src/netaddress.cpp

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2016 The Bitcoin Core developers
   3 // Distributed under the MIT software license, see the accompanying
   4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5
   6 #ifdef HAVE_CONFIG_H
   7 #include "config/bitcoin-config.h"
   8 #endif
   9
  10 #include "netaddress.h"
  11 #include "hash.h"
  12 #include "utilstrencodings.h"
  13 #include "tinyformat.h"
  14
  15 static const unsigned char pchIPv4[12] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff };
  16 static const unsigned char pchOnionCat[] = {0xFD,0x87,0xD8,0x7E,0xEB,0x43};
  17
  18 void CNetAddr::Init()
  19 {
  20     memset(ip, 0, sizeof(ip));
  21     scopeId = 0;
  22 }
  23
  24 void CNetAddr::SetIP(const CNetAddr& ipIn)
  25 {
  26     memcpy(ip, ipIn.ip, sizeof(ip));
  27 }
  28
  29 void CNetAddr::SetRaw(Network network, const uint8_t *ip_in)
  30 {
  31     switch(network)
  32     {
  33         case NET_IPV4:
  34             memcpy(ip, pchIPv4, 12);
  35             memcpy(ip+12, ip_in, 4);
  36             break;
  37         case NET_IPV6:
  38             memcpy(ip, ip_in, 16);
  39             break;
  40         default:
  41             assert(!"invalid network");
  42     }
  43 }
  44
  45 bool CNetAddr::SetSpecial(const std::string &strName)
  46 {
  47     if (strName.size()>6 && strName.substr(strName.size() - 6, 6) == ".onion") {
  48         std::vector<unsigned char> vchAddr = DecodeBase32(strName.substr(0, strName.size() - 6).c_str());
  49         if (vchAddr.size() != 16-sizeof(pchOnionCat))
  50             return false;
  51         memcpy(ip, pchOnionCat, sizeof(pchOnionCat));
  52         for (unsigned int i=0; i<16-sizeof(pchOnionCat); i++)
  53             ip[i + sizeof(pchOnionCat)] = vchAddr[i];
  54         return true;
  55     }
  56     return false;
  57 }
  58
  59 CNetAddr::CNetAddr()
  60 {
  61     Init();
  62 }
  63
  64 CNetAddr::CNetAddr(const struct in_addr& ipv4Addr)
  65 {
  66     SetRaw(NET_IPV4, (const uint8_t*)&ipv4Addr);
  67 }
  68
  69 CNetAddr::CNetAddr(const struct in6_addr& ipv6Addr, const uint32_t scope)
  70 {
  71     SetRaw(NET_IPV6, (const uint8_t*)&ipv6Addr);
  72     scopeId = scope;
  73 }
  74
  75 unsigned int CNetAddr::GetByte(int n) const
  76 {
  77     return ip[15-n];
  78 }
  79
  80 bool CNetAddr::IsIPv4() const
  81 {
  82     return (memcmp(ip, pchIPv4, sizeof(pchIPv4)) == 0);
  83 }
  84
  85 bool CNetAddr::IsIPv6() const
  86 {
  87     return (!IsIPv4() && !IsTor());
  88 }
  89
  90 bool CNetAddr::IsRFC1918() const
  91 {
  92     return IsIPv4() && (
  93         GetByte(3) == 10 ||
  94         (GetByte(3) == 192 && GetByte(2) == 168) ||
  95         (GetByte(3) == 172 && (GetByte(2) >= 16 && GetByte(2) <= 31)));
  96 }
  97
  98 bool CNetAddr::IsRFC2544() const
  99 {
 100     return IsIPv4() && GetByte(3) == 198 && (GetByte(2) == 18 || GetByte(2) == 19);
 101 }
 102
 103 bool CNetAddr::IsRFC3927() const
 104 {
 105     return IsIPv4() && (GetByte(3) == 169 && GetByte(2) == 254);
 106 }
 107
 108 bool CNetAddr::IsRFC6598() const
 109 {
 110     return IsIPv4() && GetByte(3) == 100 && GetByte(2) >= 64 && GetByte(2) <= 127;
 111 }
 112
 113 bool CNetAddr::IsRFC5737() const
 114 {
 115     return IsIPv4() && ((GetByte(3) == 192 && GetByte(2) == 0 && GetByte(1) == 2) ||
 116         (GetByte(3) == 198 && GetByte(2) == 51 && GetByte(1) == 100) ||
 117         (GetByte(3) == 203 && GetByte(2) == 0 && GetByte(1) == 113));
 118 }
 119
 120 bool CNetAddr::IsRFC3849() const
 121 {
 122     return GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0x0D && GetByte(12) == 0xB8;
 123 }
 124
 125 bool CNetAddr::IsRFC3964() const
 126 {
 127     return (GetByte(15) == 0x20 && GetByte(14) == 0x02);
 128 }
 129
 130 bool CNetAddr::IsRFC6052() const
 131 {
 132     static const unsigned char pchRFC6052[] = {0,0x64,0xFF,0x9B,0,0,0,0,0,0,0,0};
 133     return (memcmp(ip, pchRFC6052, sizeof(pchRFC6052)) == 0);
 134 }
 135
 136 bool CNetAddr::IsRFC4380() const
 137 {
 138     return (GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0 && GetByte(12) == 0);
 139 }
 140
 141 bool CNetAddr::IsRFC4862() const
 142 {
 143     static const unsigned char pchRFC4862[] = {0xFE,0x80,0,0,0,0,0,0};
 144     return (memcmp(ip, pchRFC4862, sizeof(pchRFC4862)) == 0);
 145 }
 146
 147 bool CNetAddr::IsRFC4193() const
 148 {
 149     return ((GetByte(15) & 0xFE) == 0xFC);
 150 }
 151
 152 bool CNetAddr::IsRFC6145() const
 153 {
 154     static const unsigned char pchRFC6145[] = {0,0,0,0,0,0,0,0,0xFF,0xFF,0,0};
 155     return (memcmp(ip, pchRFC6145, sizeof(pchRFC6145)) == 0);
 156 }
 157
 158 bool CNetAddr::IsRFC4843() const
 159 {
 160     return (GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0x00 && (GetByte(12) & 0xF0) == 0x10);
 161 }
 162
 163 bool CNetAddr::IsTor() const
 164 {
 165     return (memcmp(ip, pchOnionCat, sizeof(pchOnionCat)) == 0);
 166 }
 167
 168 bool CNetAddr::IsLocal() const
 169 {
 170     // IPv4 loopback
 171    if (IsIPv4() && (GetByte(3) == 127 || GetByte(3) == 0))
 172        return true;
 173
 174    // IPv6 loopback (::1/128)
 175    static const unsigned char pchLocal[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
 176    if (memcmp(ip, pchLocal, 16) == 0)
 177        return true;
 178
 179    return false;
 180 }
 181
 182 bool CNetAddr::IsMulticast() const
 183 {
 184     return    (IsIPv4() && (GetByte(3) & 0xF0) == 0xE0)
 185            || (GetByte(15) == 0xFF);
 186 }
 187
 188 bool CNetAddr::IsValid() const
 189 {
 190     // Cleanup 3-byte shifted addresses caused by garbage in size field
 191     // of addr messages from versions before 0.2.9 checksum.
 192     // Two consecutive addr messages look like this:
 193     // header20 vectorlen3 addr26 addr26 addr26 header20 vectorlen3 addr26 addr26 addr26...
 194     // so if the first length field is garbled, it reads the second batch
 195     // of addr misaligned by 3 bytes.
 196     if (memcmp(ip, pchIPv4+3, sizeof(pchIPv4)-3) == 0)
 197         return false;
 198
 199     // unspecified IPv6 address (::/128)
 200     unsigned char ipNone6[16] = {};
 201     if (memcmp(ip, ipNone6, 16) == 0)
 202         return false;
 203
 204     // documentation IPv6 address
 205     if (IsRFC3849())
 206         return false;
 207
 208     if (IsIPv4())
 209     {
 210         // INADDR_NONE
 211         uint32_t ipNone = INADDR_NONE;
 212         if (memcmp(ip+12, &ipNone, 4) == 0)
 213             return false;
 214
 215         // 0
 216         ipNone = 0;
 217         if (memcmp(ip+12, &ipNone, 4) == 0)
 218             return false;
 219     }
 220
 221     return true;
 222 }
 223
 224 bool CNetAddr::IsRoutable() const
 225 {
 226     return IsValid() && !(IsRFC1918() || IsRFC2544() || IsRFC3927() || IsRFC4862() || IsRFC6598() || IsRFC5737() || (IsRFC4193() && !IsTor()) || IsRFC4843() || IsLocal());
 227 }
 228
 229 enum Network CNetAddr::GetNetwork() const
 230 {
 231     if (!IsRoutable())
 232         return NET_UNROUTABLE;
 233
 234     if (IsIPv4())
 235         return NET_IPV4;
 236
 237     if (IsTor())
 238         return NET_TOR;
 239
 240     return NET_IPV6;
 241 }
 242
 243 std::string CNetAddr::ToStringIP() const
 244 {
 245     if (IsTor())
 246         return EncodeBase32(&ip[6], 10) + ".onion";
 247     CService serv(*this, 0);
 248     struct sockaddr_storage sockaddr;
 249     socklen_t socklen = sizeof(sockaddr);
 250     if (serv.GetSockAddr((struct sockaddr*)&sockaddr, &socklen)) {
 251         char name[1025] = "";
 252         if (!getnameinfo((const struct sockaddr*)&sockaddr, socklen, name, sizeof(name), NULL, 0, NI_NUMERICHOST))
 253             return std::string(name);
 254     }
 255     if (IsIPv4())
 256         return strprintf("%u.%u.%u.%u", GetByte(3), GetByte(2), GetByte(1), GetByte(0));
 257     else
 258         return strprintf("%x:%x:%x:%x:%x:%x:%x:%x",
 259                          GetByte(15) << 8 | GetByte(14), GetByte(13) << 8 | GetByte(12),
 260                          GetByte(11) << 8 | GetByte(10), GetByte(9) << 8 | GetByte(8),
 261                          GetByte(7) << 8 | GetByte(6), GetByte(5) << 8 | GetByte(4),
 262                          GetByte(3) << 8 | GetByte(2), GetByte(1) << 8 | GetByte(0));
 263 }
 264
 265 std::string CNetAddr::ToString() const
 266 {
 267     return ToStringIP();
 268 }
 269
 270 bool operator==(const CNetAddr& a, const CNetAddr& b)
 271 {
 272     return (memcmp(a.ip, b.ip, 16) == 0);
 273 }
 274
 275 bool operator!=(const CNetAddr& a, const CNetAddr& b)
 276 {
 277     return (memcmp(a.ip, b.ip, 16) != 0);
 278 }
 279
 280 bool operator<(const CNetAddr& a, const CNetAddr& b)
 281 {
 282     return (memcmp(a.ip, b.ip, 16) < 0);
 283 }
 284
 285 bool CNetAddr::GetInAddr(struct in_addr* pipv4Addr) const
 286 {
 287     if (!IsIPv4())
 288         return false;
 289     memcpy(pipv4Addr, ip+12, 4);
 290     return true;
 291 }
 292
 293 bool CNetAddr::GetIn6Addr(struct in6_addr* pipv6Addr) const
 294 {
 295     memcpy(pipv6Addr, ip, 16);
 296     return true;
 297 }
 298
 299 // get canonical identifier of an address' group
 300 // no two connections will be attempted to addresses with the same group
 301 std::vector<unsigned char> CNetAddr::GetGroup() const
 302 {
 303     std::vector<unsigned char> vchRet;
 304     int nClass = NET_IPV6;
 305     int nStartByte = 0;
 306     int nBits = 16;
 307
 308     // all local addresses belong to the same group
 309     if (IsLocal())
 310     {
 311         nClass = 255;
 312         nBits = 0;
 313     }
 314
 315     // all unroutable addresses belong to the same group
 316     if (!IsRoutable())
 317     {
 318         nClass = NET_UNROUTABLE;
 319         nBits = 0;
 320     }
 321     // for IPv4 addresses, '1' + the 16 higher-order bits of the IP
 322     // includes mapped IPv4, SIIT translated IPv4, and the well-known prefix
 323     else if (IsIPv4() || IsRFC6145() || IsRFC6052())
 324     {
 325         nClass = NET_IPV4;
 326         nStartByte = 12;
 327     }
 328     // for 6to4 tunnelled addresses, use the encapsulated IPv4 address
 329     else if (IsRFC3964())
 330     {
 331         nClass = NET_IPV4;
 332         nStartByte = 2;
 333     }
 334     // for Teredo-tunnelled IPv6 addresses, use the encapsulated IPv4 address
 335     else if (IsRFC4380())
 336     {
 337         vchRet.push_back(NET_IPV4);
 338         vchRet.push_back(GetByte(3) ^ 0xFF);
 339         vchRet.push_back(GetByte(2) ^ 0xFF);
 340         return vchRet;
 341     }
 342     else if (IsTor())
 343     {
 344         nClass = NET_TOR;
 345         nStartByte = 6;
 346         nBits = 4;
 347     }
 348     // for he.net, use /36 groups
 349     else if (GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0x04 && GetByte(12) == 0x70)
 350         nBits = 36;
 351     // for the rest of the IPv6 network, use /32 groups
 352     else
 353         nBits = 32;
 354
 355     vchRet.push_back(nClass);
 356     while (nBits >= 8)
 357     {
 358         vchRet.push_back(GetByte(15 - nStartByte));
 359         nStartByte++;
 360         nBits -= 8;
 361     }
 362     if (nBits > 0)
 363         vchRet.push_back(GetByte(15 - nStartByte) | ((1 << (8 - nBits)) - 1));
 364
 365     return vchRet;
 366 }
 367
 368 uint64_t CNetAddr::GetHash() const
 369 {
 370     uint256 hash = Hash(&ip[0], &ip[16]);
 371     uint64_t nRet;
 372     memcpy(&nRet, &hash, sizeof(nRet));
 373     return nRet;
 374 }
 375
 376 // private extensions to enum Network, only returned by GetExtNetwork,
 377 // and only used in GetReachabilityFrom
 378 static const int NET_UNKNOWN = NET_MAX + 0;
 379 static const int NET_TEREDO  = NET_MAX + 1;
 380 int static GetExtNetwork(const CNetAddr *addr)
 381 {
 382     if (addr == NULL)
 383         return NET_UNKNOWN;
 384     if (addr->IsRFC4380())
 385         return NET_TEREDO;
 386     return addr->GetNetwork();
 387 }
 388
 389 /** Calculates a metric for how reachable (*this) is from a given partner */
 390 int CNetAddr::GetReachabilityFrom(const CNetAddr *paddrPartner) const
 391 {
 392     enum Reachability {
 393         REACH_UNREACHABLE,
 394         REACH_DEFAULT,
 395         REACH_TEREDO,
 396         REACH_IPV6_WEAK,
 397         REACH_IPV4,
 398         REACH_IPV6_STRONG,
 399         REACH_PRIVATE
 400     };
 401
 402     if (!IsRoutable())
 403         return REACH_UNREACHABLE;
 404
 405     int ourNet = GetExtNetwork(this);
 406     int theirNet = GetExtNetwork(paddrPartner);
 407     bool fTunnel = IsRFC3964() || IsRFC6052() || IsRFC6145();
 408
 409     switch(theirNet) {
 410     case NET_IPV4:
 411         switch(ourNet) {
 412         default:       return REACH_DEFAULT;
 413         case NET_IPV4: return REACH_IPV4;
 414         }
 415     case NET_IPV6:
 416         switch(ourNet) {
 417         default:         return REACH_DEFAULT;
 418         case NET_TEREDO: return REACH_TEREDO;
 419         case NET_IPV4:   return REACH_IPV4;
 420         case NET_IPV6:   return fTunnel ? REACH_IPV6_WEAK : REACH_IPV6_STRONG; // only prefer giving our IPv6 address if it's not tunnelled
 421         }
 422     case NET_TOR:
 423         switch(ourNet) {
 424         default:         return REACH_DEFAULT;
 425         case NET_IPV4:   return REACH_IPV4; // Tor users can connect to IPv4 as well
 426         case NET_TOR:    return REACH_PRIVATE;
 427         }
 428     case NET_TEREDO:
 429         switch(ourNet) {
 430         default:          return REACH_DEFAULT;
 431         case NET_TEREDO:  return REACH_TEREDO;
 432         case NET_IPV6:    return REACH_IPV6_WEAK;
 433         case NET_IPV4:    return REACH_IPV4;
 434         }
 435     case NET_UNKNOWN:
 436     case NET_UNROUTABLE:
 437     default:
 438         switch(ourNet) {
 439         default:          return REACH_DEFAULT;
 440         case NET_TEREDO:  return REACH_TEREDO;
 441         case NET_IPV6:    return REACH_IPV6_WEAK;
 442         case NET_IPV4:    return REACH_IPV4;
 443         case NET_TOR:     return REACH_PRIVATE; // either from Tor, or don't care about our address
 444         }
 445     }
 446 }
 447
 448 void CService::Init()
 449 {
 450     port = 0;
 451 }
 452
 453 CService::CService()
 454 {
 455     Init();
 456 }
 457
 458 CService::CService(const CNetAddr& cip, unsigned short portIn) : CNetAddr(cip), port(portIn)
 459 {
 460 }
 461
 462 CService::CService(const struct in_addr& ipv4Addr, unsigned short portIn) : CNetAddr(ipv4Addr), port(portIn)
 463 {
 464 }
 465
 466 CService::CService(const struct in6_addr& ipv6Addr, unsigned short portIn) : CNetAddr(ipv6Addr), port(portIn)
 467 {
 468 }
 469
 470 CService::CService(const struct sockaddr_in& addr) : CNetAddr(addr.sin_addr), port(ntohs(addr.sin_port))
 471 {
 472     assert(addr.sin_family == AF_INET);
 473 }
 474
 475 CService::CService(const struct sockaddr_in6 &addr) : CNetAddr(addr.sin6_addr, addr.sin6_scope_id), port(ntohs(addr.sin6_port))
 476 {
 477    assert(addr.sin6_family == AF_INET6);
 478 }
 479
 480 bool CService::SetSockAddr(const struct sockaddr *paddr)
 481 {
 482     switch (paddr->sa_family) {
 483     case AF_INET:
 484         *this = CService(*(const struct sockaddr_in*)paddr);
 485         return true;
 486     case AF_INET6:
 487         *this = CService(*(const struct sockaddr_in6*)paddr);
 488         return true;
 489     default:
 490         return false;
 491     }
 492 }
 493
 494 unsigned short CService::GetPort() const
 495 {
 496     return port;
 497 }
 498
 499 bool operator==(const CService& a, const CService& b)
 500 {
 501     return (CNetAddr)a == (CNetAddr)b && a.port == b.port;
 502 }
 503
 504 bool operator!=(const CService& a, const CService& b)
 505 {
 506     return (CNetAddr)a != (CNetAddr)b || a.port != b.port;
 507 }
 508
 509 bool operator<(const CService& a, const CService& b)
 510 {
 511     return (CNetAddr)a < (CNetAddr)b || ((CNetAddr)a == (CNetAddr)b && a.port < b.port);
 512 }
 513
 514 bool CService::GetSockAddr(struct sockaddr* paddr, socklen_t *addrlen) const
 515 {
 516     if (IsIPv4()) {
 517         if (*addrlen < (socklen_t)sizeof(struct sockaddr_in))
 518             return false;
 519         *addrlen = sizeof(struct sockaddr_in);
 520         struct sockaddr_in *paddrin = (struct sockaddr_in*)paddr;
 521         memset(paddrin, 0, *addrlen);
 522         if (!GetInAddr(&paddrin->sin_addr))
 523             return false;
 524         paddrin->sin_family = AF_INET;
 525         paddrin->sin_port = htons(port);
 526         return true;
 527     }
 528     if (IsIPv6()) {
 529         if (*addrlen < (socklen_t)sizeof(struct sockaddr_in6))
 530             return false;
 531         *addrlen = sizeof(struct sockaddr_in6);
 532         struct sockaddr_in6 *paddrin6 = (struct sockaddr_in6*)paddr;
 533         memset(paddrin6, 0, *addrlen);
 534         if (!GetIn6Addr(&paddrin6->sin6_addr))
 535             return false;
 536         paddrin6->sin6_scope_id = scopeId;
 537         paddrin6->sin6_family = AF_INET6;
 538         paddrin6->sin6_port = htons(port);
 539         return true;
 540     }
 541     return false;
 542 }
 543
 544 std::vector<unsigned char> CService::GetKey() const
 545 {
 546      std::vector<unsigned char> vKey;
 547      vKey.resize(18);
 548      memcpy(&vKey[0], ip, 16);
 549      vKey[16] = port / 0x100;
 550      vKey[17] = port & 0x0FF;
 551      return vKey;
 552 }
 553
 554 std::string CService::ToStringPort() const
 555 {
 556     return strprintf("%u", port);
 557 }
 558
 559 std::string CService::ToStringIPPort() const
 560 {
 561     if (IsIPv4() || IsTor()) {
 562         return ToStringIP() + ":" + ToStringPort();
 563     } else {
 564         return "[" + ToStringIP() + "]:" + ToStringPort();
 565     }
 566 }
 567
 568 std::string CService::ToString() const
 569 {
 570     return ToStringIPPort();
 571 }
 572
 573 void CService::SetPort(unsigned short portIn)
 574 {
 575     port = portIn;
 576 }
 577
 578 CSubNet::CSubNet():
 579     valid(false)
 580 {
 581     memset(netmask, 0, sizeof(netmask));
 582 }
 583
 584 CSubNet::CSubNet(const CNetAddr &addr, int32_t mask)
 585 {
 586     valid = true;
 587     network = addr;
 588     // Default to /32 (IPv4) or /128 (IPv6), i.e. match single address
 589     memset(netmask, 255, sizeof(netmask));
 590
 591     // IPv4 addresses start at offset 12, and first 12 bytes must match, so just offset n
 592     const int astartofs = network.IsIPv4() ? 12 : 0;
 593
 594     int32_t n = mask;
 595     if(n >= 0 && n <= (128 - astartofs*8)) // Only valid if in range of bits of address
 596     {
 597         n += astartofs*8;
 598         // Clear bits [n..127]
 599         for (; n < 128; ++n)
 600             netmask[n>>3] &= ~(1<<(7-(n&7)));
 601     } else
 602         valid = false;
 603
 604     // Normalize network according to netmask
 605     for(int x=0; x<16; ++x)
 606         network.ip[x] &= netmask[x];
 607 }
 608
 609 CSubNet::CSubNet(const CNetAddr &addr, const CNetAddr &mask)
 610 {
 611     valid = true;
 612     network = addr;
 613     // Default to /32 (IPv4) or /128 (IPv6), i.e. match single address
 614     memset(netmask, 255, sizeof(netmask));
 615
 616     // IPv4 addresses start at offset 12, and first 12 bytes must match, so just offset n
 617     const int astartofs = network.IsIPv4() ? 12 : 0;
 618
 619     for(int x=astartofs; x<16; ++x)
 620         netmask[x] = mask.ip[x];
 621
 622     // Normalize network according to netmask
 623     for(int x=0; x<16; ++x)
 624         network.ip[x] &= netmask[x];
 625 }
 626
 627 CSubNet::CSubNet(const CNetAddr &addr):
 628     valid(addr.IsValid())
 629 {
 630     memset(netmask, 255, sizeof(netmask));
 631     network = addr;
 632 }
 633
 634 bool CSubNet::Match(const CNetAddr &addr) const
 635 {
 636     if (!valid || !addr.IsValid())
 637         return false;
 638     for(int x=0; x<16; ++x)
 639         if ((addr.ip[x] & netmask[x]) != network.ip[x])
 640             return false;
 641     return true;
 642 }
 643
 644 static inline int NetmaskBits(uint8_t x)
 645 {
 646     switch(x) {
 647     case 0x00: return 0; break;
 648     case 0x80: return 1; break;
 649     case 0xc0: return 2; break;
 650     case 0xe0: return 3; break;
 651     case 0xf0: return 4; break;
 652     case 0xf8: return 5; break;
 653     case 0xfc: return 6; break;
 654     case 0xfe: return 7; break;
 655     case 0xff: return 8; break;
 656     default: return -1; break;
 657     }
 658 }
 659
 660 std::string CSubNet::ToString() const
 661 {
 662     /* Parse binary 1{n}0{N-n} to see if mask can be represented as /n */
 663     int cidr = 0;
 664     bool valid_cidr = true;
 665     int n = network.IsIPv4() ? 12 : 0;
 666     for (; n < 16 && netmask[n] == 0xff; ++n)
 667         cidr += 8;
 668     if (n < 16) {
 669         int bits = NetmaskBits(netmask[n]);
 670         if (bits < 0)
 671             valid_cidr = false;
 672         else
 673             cidr += bits;
 674         ++n;
 675     }
 676     for (; n < 16 && valid_cidr; ++n)
 677         if (netmask[n] != 0x00)
 678             valid_cidr = false;
 679
 680     /* Format output */
 681     std::string strNetmask;
 682     if (valid_cidr) {
 683         strNetmask = strprintf("%u", cidr);
 684     } else {
 685         if (network.IsIPv4())
 686             strNetmask = strprintf("%u.%u.%u.%u", netmask[12], netmask[13], netmask[14], netmask[15]);
 687         else
 688             strNetmask = strprintf("%x:%x:%x:%x:%x:%x:%x:%x",
 689                              netmask[0] << 8 | netmask[1], netmask[2] << 8 | netmask[3],
 690                              netmask[4] << 8 | netmask[5], netmask[6] << 8 | netmask[7],
 691                              netmask[8] << 8 | netmask[9], netmask[10] << 8 | netmask[11],
 692                              netmask[12] << 8 | netmask[13], netmask[14] << 8 | netmask[15]);
 693     }
 694
 695     return network.ToString() + "/" + strNetmask;
 696 }
 697
 698 bool CSubNet::IsValid() const
 699 {
 700     return valid;
 701 }
 702
 703 bool operator==(const CSubNet& a, const CSubNet& b)
 704 {
 705     return a.valid == b.valid && a.network == b.network && !memcmp(a.netmask, b.netmask, 16);
 706 }
 707
 708 bool operator!=(const CSubNet& a, const CSubNet& b)
 709 {
 710     return !(a==b);
 711 }
 712
 713 bool operator<(const CSubNet& a, const CSubNet& b)
 714 {
 715     return (a.network < b.network || (a.network == b.network && memcmp(a.netmask, b.netmask, 16) < 0));
 716 }