1/*
2 * Copyright 2014-present Facebook, Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <folly/IPAddressV6.h>
18
19#include <ostream>
20#include <string>
21
22#include <folly/Format.h>
23#include <folly/IPAddress.h>
24#include <folly/IPAddressV4.h>
25#include <folly/MacAddress.h>
26#include <folly/detail/IPAddressSource.h>
27
28#if !_WIN32
29#include <net/if.h>
30#else
31// Because of the massive pain that is libnl, this can't go into the socket
32// portability header as you can't include <linux/if.h> and <net/if.h> in
33// the same translation unit without getting errors -_-...
34#include <iphlpapi.h> // @manual
35#include <ntddndis.h> // @manual
36
37// Alias the max size of an interface name to what posix expects.
38#define IFNAMSIZ IF_NAMESIZE
39#endif
40
41using std::ostream;
42using std::string;
43
44namespace folly {
45
46// public static const
47const uint32_t IPAddressV6::PREFIX_TEREDO = 0x20010000;
48const uint32_t IPAddressV6::PREFIX_6TO4 = 0x2002;
49
50// free functions
51size_t hash_value(const IPAddressV6& addr) {
52 return addr.hash();
53}
54ostream& operator<<(ostream& os, const IPAddressV6& addr) {
55 os << addr.str();
56 return os;
57}
58void toAppend(IPAddressV6 addr, string* result) {
59 result->append(addr.str());
60}
61void toAppend(IPAddressV6 addr, fbstring* result) {
62 result->append(addr.str());
63}
64
65bool IPAddressV6::validate(StringPiece ip) noexcept {
66 return tryFromString(ip).hasValue();
67}
68
69// public default constructor
70IPAddressV6::IPAddressV6() {}
71
72// public string constructor
73IPAddressV6::IPAddressV6(StringPiece addr) {
74 auto maybeIp = tryFromString(addr);
75 if (maybeIp.hasError()) {
76 throw IPAddressFormatException(
77 to<std::string>("Invalid IPv6 address '", addr, "'"));
78 }
79 *this = std::move(maybeIp.value());
80}
81
82Expected<IPAddressV6, IPAddressFormatError> IPAddressV6::tryFromString(
83 StringPiece str) noexcept {
84 auto ip = str.str();
85
86 // Allow addresses surrounded in brackets
87 if (ip.size() < 2) {
88 return makeUnexpected(IPAddressFormatError::INVALID_IP);
89 }
90 if (ip.front() == '[' && ip.back() == ']') {
91 ip = ip.substr(1, ip.size() - 2);
92 }
93
94 struct addrinfo* result;
95 struct addrinfo hints;
96 memset(&hints, 0, sizeof(hints));
97 hints.ai_family = AF_INET6;
98 hints.ai_socktype = SOCK_STREAM;
99 hints.ai_flags = AI_NUMERICHOST;
100 if (::getaddrinfo(ip.c_str(), nullptr, &hints, &result) == 0) {
101 SCOPE_EXIT {
102 ::freeaddrinfo(result);
103 };
104 const struct sockaddr_in6* sa =
105 reinterpret_cast<struct sockaddr_in6*>(result->ai_addr);
106 return IPAddressV6(*sa);
107 }
108 return makeUnexpected(IPAddressFormatError::INVALID_IP);
109}
110
111// in6_addr constructor
112IPAddressV6::IPAddressV6(const in6_addr& src) noexcept : addr_(src) {}
113
114// sockaddr_in6 constructor
115IPAddressV6::IPAddressV6(const sockaddr_in6& src) noexcept
116 : addr_(src.sin6_addr), scope_(uint16_t(src.sin6_scope_id)) {}
117
118// ByteArray16 constructor
119IPAddressV6::IPAddressV6(const ByteArray16& src) noexcept : addr_(src) {}
120
121// link-local constructor
122IPAddressV6::IPAddressV6(LinkLocalTag, MacAddress mac) : addr_(mac) {}
123
124IPAddressV6::AddressStorage::AddressStorage(MacAddress mac) {
125 // The link-local address uses modified EUI-64 format,
126 // See RFC 4291 sections 2.5.1, 2.5.6, and Appendix A
127 const auto* macBytes = mac.bytes();
128 memcpy(&bytes_.front(), "\xfe\x80\x00\x00\x00\x00\x00\x00", 8);
129 bytes_[8] = uint8_t(macBytes[0] ^ 0x02);
130 bytes_[9] = macBytes[1];
131 bytes_[10] = macBytes[2];
132 bytes_[11] = 0xff;
133 bytes_[12] = 0xfe;
134 bytes_[13] = macBytes[3];
135 bytes_[14] = macBytes[4];
136 bytes_[15] = macBytes[5];
137}
138
139Optional<MacAddress> IPAddressV6::getMacAddressFromLinkLocal() const {
140 // Returned MacAddress must be constructed from a link-local IPv6 address.
141 if (!isLinkLocal()) {
142 return folly::none;
143 }
144 return getMacAddressFromEUI64();
145}
146
147Optional<MacAddress> IPAddressV6::getMacAddressFromEUI64() const {
148 if (!(addr_.bytes_[11] == 0xff && addr_.bytes_[12] == 0xfe)) {
149 return folly::none;
150 }
151 // The auto configured address uses modified EUI-64 format,
152 // See RFC 4291 sections 2.5.1, 2.5.6, and Appendix A
153 std::array<uint8_t, MacAddress::SIZE> bytes;
154 // Step 1: first 8 bytes are network prefix, and can be stripped
155 // Step 2: invert the universal/local (U/L) flag (bit 7)
156 bytes[0] = addr_.bytes_[8] ^ 0x02;
157 // Step 3: copy these bytes as they are
158 bytes[1] = addr_.bytes_[9];
159 bytes[2] = addr_.bytes_[10];
160 // Step 4: strip bytes (0xfffe), which are bytes_[11] and bytes_[12]
161 // Step 5: copy the rest.
162 bytes[3] = addr_.bytes_[13];
163 bytes[4] = addr_.bytes_[14];
164 bytes[5] = addr_.bytes_[15];
165 return Optional<MacAddress>(MacAddress::fromBinary(range(bytes)));
166}
167
168IPAddressV6 IPAddressV6::fromBinary(ByteRange bytes) {
169 auto maybeIp = tryFromBinary(bytes);
170 if (maybeIp.hasError()) {
171 throw IPAddressFormatException(to<std::string>(
172 "Invalid IPv6 binary data: length must be 16 bytes, got ",
173 bytes.size()));
174 }
175 return maybeIp.value();
176}
177
178Expected<IPAddressV6, IPAddressFormatError> IPAddressV6::tryFromBinary(
179 ByteRange bytes) noexcept {
180 IPAddressV6 addr;
181 auto setResult = addr.trySetFromBinary(bytes);
182 if (setResult.hasError()) {
183 return makeUnexpected(std::move(setResult.error()));
184 }
185 return addr;
186}
187
188Expected<Unit, IPAddressFormatError> IPAddressV6::trySetFromBinary(
189 ByteRange bytes) noexcept {
190 if (bytes.size() != 16) {
191 return makeUnexpected(IPAddressFormatError::INVALID_IP);
192 }
193 memcpy(&addr_.in6Addr_.s6_addr, bytes.data(), sizeof(in6_addr));
194 scope_ = 0;
195 return unit;
196}
197
198// static
199IPAddressV6 IPAddressV6::fromInverseArpaName(const std::string& arpaname) {
200 auto piece = StringPiece(arpaname);
201 if (!piece.removeSuffix(".ip6.arpa")) {
202 throw IPAddressFormatException(sformat(
203 "Invalid input. Should end with 'ip6.arpa'. Got '{}'", arpaname));
204 }
205 std::vector<StringPiece> pieces;
206 split(".", piece, pieces);
207 if (pieces.size() != 32) {
208 throw IPAddressFormatException(sformat("Invalid input. Got '{}'", piece));
209 }
210 std::array<char, IPAddressV6::kToFullyQualifiedSize> ip;
211 size_t pos = 0;
212 int count = 0;
213 for (size_t i = 1; i <= pieces.size(); i++) {
214 ip[pos] = pieces[pieces.size() - i][0];
215 pos++;
216 count++;
217 // add ':' every 4 chars
218 if (count == 4 && pos < ip.size()) {
219 ip[pos++] = ':';
220 count = 0;
221 }
222 }
223 return IPAddressV6(folly::range(ip));
224}
225
226// public
227IPAddressV4 IPAddressV6::createIPv4() const {
228 if (!isIPv4Mapped()) {
229 throw IPAddressFormatException("addr is not v4-to-v6-mapped");
230 }
231 const unsigned char* by = bytes();
232 return IPAddressV4(detail::Bytes::mkAddress4(&by[12]));
233}
234
235// convert two uint8_t bytes into a uint16_t as hibyte.lobyte
236static inline uint16_t unpack(uint8_t lobyte, uint8_t hibyte) {
237 return uint16_t((uint16_t(hibyte) << 8) | lobyte);
238}
239
240// given a src string, unpack count*2 bytes into dest
241// dest must have as much storage as count
242static inline void
243unpackInto(const unsigned char* src, uint16_t* dest, size_t count) {
244 for (size_t i = 0, hi = 1, lo = 0; i < count; i++) {
245 dest[i] = unpack(src[hi], src[lo]);
246 hi += 2;
247 lo += 2;
248 }
249}
250
251// public
252IPAddressV4 IPAddressV6::getIPv4For6To4() const {
253 if (!is6To4()) {
254 throw IPAddressV6::TypeError(
255 sformat("Invalid IP '{}': not a 6to4 address", str()));
256 }
257 // convert 16x8 bytes into first 4x16 bytes
258 uint16_t ints[4] = {0, 0, 0, 0};
259 unpackInto(bytes(), ints, 4);
260 // repack into 4x8
261 union {
262 unsigned char bytes[4];
263 in_addr addr;
264 } ipv4;
265 ipv4.bytes[0] = (uint8_t)((ints[1] & 0xFF00) >> 8);
266 ipv4.bytes[1] = (uint8_t)(ints[1] & 0x00FF);
267 ipv4.bytes[2] = (uint8_t)((ints[2] & 0xFF00) >> 8);
268 ipv4.bytes[3] = (uint8_t)(ints[2] & 0x00FF);
269 return IPAddressV4(ipv4.addr);
270}
271
272// public
273bool IPAddressV6::isIPv4Mapped() const {
274 // v4 mapped addresses have their first 10 bytes set to 0, the next 2 bytes
275 // set to 255 (0xff);
276 const unsigned char* by = bytes();
277
278 // check if first 10 bytes are 0
279 for (int i = 0; i < 10; i++) {
280 if (by[i] != 0x00) {
281 return false;
282 }
283 }
284 // check if bytes 11 and 12 are 255
285 if (by[10] == 0xff && by[11] == 0xff) {
286 return true;
287 }
288 return false;
289}
290
291// public
292IPAddressV6::Type IPAddressV6::type() const {
293 // convert 16x8 bytes into first 2x16 bytes
294 uint16_t ints[2] = {0, 0};
295 unpackInto(bytes(), ints, 2);
296
297 if ((((uint32_t)ints[0] << 16) | ints[1]) == IPAddressV6::PREFIX_TEREDO) {
298 return Type::TEREDO;
299 }
300
301 if ((uint32_t)ints[0] == IPAddressV6::PREFIX_6TO4) {
302 return Type::T6TO4;
303 }
304
305 return Type::NORMAL;
306}
307
308// public
309string IPAddressV6::toJson() const {
310 return sformat("{{family:'AF_INET6', addr:'{}', hash:{}}}", str(), hash());
311}
312
313// public
314size_t IPAddressV6::hash() const {
315 if (isIPv4Mapped()) {
316 /* An IPAddress containing this object would be equal (i.e. operator==)
317 to an IPAddress containing the corresponding IPv4.
318 So we must make sure that the hash values are the same as well */
319 return IPAddress::createIPv4(*this).hash();
320 }
321
322 static const uint64_t seed = AF_INET6;
323 uint64_t hash1 = 0, hash2 = 0;
324 hash::SpookyHashV2::Hash128(&addr_, 16, &hash1, &hash2);
325 return hash::hash_combine(seed, hash1, hash2);
326}
327
328// public
329bool IPAddressV6::inSubnet(StringPiece cidrNetwork) const {
330 auto subnetInfo = IPAddress::createNetwork(cidrNetwork);
331 auto addr = subnetInfo.first;
332 if (!addr.isV6()) {
333 throw IPAddressFormatException(
334 sformat("Address '{}' is not a V6 address", addr.toJson()));
335 }
336 return inSubnetWithMask(addr.asV6(), fetchMask(subnetInfo.second));
337}
338
339// public
340bool IPAddressV6::inSubnetWithMask(
341 const IPAddressV6& subnet,
342 const ByteArray16& cidrMask) const {
343 const auto mask = detail::Bytes::mask(toByteArray(), cidrMask);
344 const auto subMask = detail::Bytes::mask(subnet.toByteArray(), cidrMask);
345 return (mask == subMask);
346}
347
348// public
349bool IPAddressV6::isLoopback() const {
350 // Check if v4 mapped is loopback
351 if (isIPv4Mapped() && createIPv4().isLoopback()) {
352 return true;
353 }
354 auto socka = toSockAddr();
355 return IN6_IS_ADDR_LOOPBACK(&socka.sin6_addr);
356}
357
358bool IPAddressV6::isRoutable() const {
359 return
360 // 2000::/3 is the only assigned global unicast block
361 inBinarySubnet({{0x20, 0x00}}, 3) ||
362 // ffxe::/16 are global scope multicast addresses,
363 // which are eligible to be routed over the internet
364 (isMulticast() && getMulticastScope() == 0xe);
365}
366
367bool IPAddressV6::isLinkLocalBroadcast() const {
368 static const IPAddressV6 kLinkLocalBroadcast("ff02::1");
369 return *this == kLinkLocalBroadcast;
370}
371
372// public
373bool IPAddressV6::isPrivate() const {
374 // Check if mapped is private
375 if (isIPv4Mapped() && createIPv4().isPrivate()) {
376 return true;
377 }
378 return isLoopback() || inBinarySubnet({{0xfc, 0x00}}, 7);
379}
380
381// public
382bool IPAddressV6::isLinkLocal() const {
383 return inBinarySubnet({{0xfe, 0x80}}, 10);
384}
385
386bool IPAddressV6::isMulticast() const {
387 return addr_.bytes_[0] == 0xff;
388}
389
390uint8_t IPAddressV6::getMulticastFlags() const {
391 DCHECK(isMulticast());
392 return uint8_t((addr_.bytes_[1] >> 4) & 0xf);
393}
394
395uint8_t IPAddressV6::getMulticastScope() const {
396 DCHECK(isMulticast());
397 return uint8_t(addr_.bytes_[1] & 0xf);
398}
399
400IPAddressV6 IPAddressV6::getSolicitedNodeAddress() const {
401 // Solicted node addresses must be constructed from unicast (or anycast)
402 // addresses
403 DCHECK(!isMulticast());
404
405 uint8_t bytes[16] = {
406 0xff,
407 0x02,
408 0x00,
409 0x00,
410 0x00,
411 0x00,
412 0x00,
413 0x00,
414 0x00,
415 0x00,
416 0x00,
417 0x01,
418 0xff,
419 addr_.bytes_[13],
420 addr_.bytes_[14],
421 addr_.bytes_[15],
422 };
423 return IPAddressV6::fromBinary(ByteRange(bytes, 16));
424}
425
426// public
427IPAddressV6 IPAddressV6::mask(size_t numBits) const {
428 static const auto bits = bitCount();
429 if (numBits > bits) {
430 throw IPAddressFormatException(
431 sformat("numBits({}) > bitCount({})", numBits, bits));
432 }
433 ByteArray16 ba = detail::Bytes::mask(fetchMask(numBits), addr_.bytes_);
434 return IPAddressV6(ba);
435}
436
437// public
438string IPAddressV6::str() const {
439 char buffer[INET6_ADDRSTRLEN + IFNAMSIZ + 1];
440
441 if (!inet_ntop(AF_INET6, toAddr().s6_addr, buffer, INET6_ADDRSTRLEN)) {
442 throw IPAddressFormatException(sformat(
443 "Invalid address with hex '{}' with error {}",
444 detail::Bytes::toHex(bytes(), 16),
445 errnoStr(errno)));
446 }
447
448 auto scopeId = getScopeId();
449 if (scopeId != 0) {
450 auto len = strlen(buffer);
451 buffer[len] = '%';
452
453 auto errsv = errno;
454 if (!if_indextoname(scopeId, buffer + len + 1)) {
455 // if we can't map the if because eg. it no longer exists,
456 // append the if index instead
457 snprintf(buffer + len + 1, IFNAMSIZ, "%u", scopeId);
458 }
459 errno = errsv;
460 }
461
462 return string(buffer);
463}
464
465// public
466string IPAddressV6::toFullyQualified() const {
467 return detail::fastIpv6ToString(addr_.in6Addr_);
468}
469
470// public
471void IPAddressV6::toFullyQualifiedAppend(std::string& out) const {
472 detail::fastIpv6AppendToString(addr_.in6Addr_, out);
473}
474
475// public
476string IPAddressV6::toInverseArpaName() const {
477 constexpr folly::StringPiece lut = "0123456789abcdef";
478 std::array<char, 32> a;
479 int j = 0;
480 for (int i = 15; i >= 0; i--) {
481 a[j] = (lut[bytes()[i] & 0xf]);
482 a[j + 1] = (lut[bytes()[i] >> 4]);
483 j += 2;
484 }
485 return sformat("{}.ip6.arpa", join(".", a));
486}
487
488// public
489uint8_t IPAddressV6::getNthMSByte(size_t byteIndex) const {
490 const auto highestIndex = byteCount() - 1;
491 if (byteIndex > highestIndex) {
492 throw std::invalid_argument(sformat(
493 "Byte index must be <= {} for addresses of type: {}",
494 highestIndex,
495 detail::familyNameStr(AF_INET6)));
496 }
497 return bytes()[byteIndex];
498}
499
500// protected
501const ByteArray16 IPAddressV6::fetchMask(size_t numBits) {
502 static const size_t bits = bitCount();
503 if (numBits > bits) {
504 throw IPAddressFormatException("IPv6 addresses are 128 bits.");
505 }
506 if (numBits == 0) {
507 return {{0}};
508 }
509 constexpr auto _0s = uint64_t(0);
510 constexpr auto _1s = ~_0s;
511 auto const fragment = Endian::big(_1s << ((128 - numBits) % 64));
512 auto const hi = numBits <= 64 ? fragment : _1s;
513 auto const lo = numBits <= 64 ? _0s : fragment;
514 uint64_t const parts[] = {hi, lo};
515 ByteArray16 arr;
516 std::memcpy(arr.data(), parts, sizeof(parts));
517 return arr;
518}
519
520// public static
521CIDRNetworkV6 IPAddressV6::longestCommonPrefix(
522 const CIDRNetworkV6& one,
523 const CIDRNetworkV6& two) {
524 auto prefix = detail::Bytes::longestCommonPrefix(
525 one.first.addr_.bytes_, one.second, two.first.addr_.bytes_, two.second);
526 return {IPAddressV6(prefix.first), prefix.second};
527}
528
529// protected
530bool IPAddressV6::inBinarySubnet(
531 const std::array<uint8_t, 2> addr,
532 size_t numBits) const {
533 auto masked = mask(numBits);
534 return (std::memcmp(addr.data(), masked.bytes(), 2) == 0);
535}
536} // namespace folly
537