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#pragma once
18
19#include <cstring>
20
21#include <array>
22#include <functional>
23#include <iosfwd>
24#include <map>
25#include <stdexcept>
26
27#include <folly/Expected.h>
28#include <folly/FBString.h>
29#include <folly/IPAddressException.h>
30#include <folly/Optional.h>
31#include <folly/Range.h>
32#include <folly/detail/IPAddress.h>
33#include <folly/hash/Hash.h>
34
35namespace folly {
36
37class IPAddress;
38class IPAddressV4;
39class IPAddressV6;
40class MacAddress;
41
42/**
43 * Pair of IPAddressV6, netmask
44 */
45typedef std::pair<IPAddressV6, uint8_t> CIDRNetworkV6;
46
47/**
48 * Specialization for IPv6 addresses
49 */
50typedef std::array<uint8_t, 16> ByteArray16;
51
52/**
53 * IPv6 variation of IPAddress.
54 *
55 * Added methods: createIPv4, getIPv4For6To4, is6To4,
56 * isTeredo, isIPv4Mapped, tryCreateIPv4, type
57 *
58 * @see IPAddress
59 *
60 * Notes on scope ID parsing:
61 *
62 * getaddrinfo() uses if_nametoindex() to convert interface names
63 * into a numerical index. For instance,
64 * "fe80::202:c9ff:fec1:ee08%eth0" may return scope ID 2 on some
65 * hosts, but other numbers on other hosts. It will fail entirely on
66 * hosts without an eth0 interface.
67 *
68 * Serializing / Deserializing IPAddressB6's on different hosts
69 * that use link-local scoping probably won't work.
70 */
71class IPAddressV6 {
72 public:
73 // V6 Address Type
74 enum Type {
75 TEREDO,
76 T6TO4,
77 NORMAL,
78 };
79 // A constructor parameter to indicate that we should create a link-local
80 // IPAddressV6.
81 enum LinkLocalTag {
82 LINK_LOCAL,
83 };
84 // Thrown when a type assertion fails
85 typedef std::runtime_error TypeError;
86
87 // Binary prefix for teredo networks
88 static const uint32_t PREFIX_TEREDO;
89 // Binary prefix for 6to4 networks
90 static const uint32_t PREFIX_6TO4;
91
92 // Size of std::string returned by toFullyQualified.
93 static constexpr size_t kToFullyQualifiedSize =
94 8 /*words*/ * 4 /*hex chars per word*/ + 7 /*separators*/;
95
96 // returns true iff the input string can be parsed as an ipv6-address
97 static bool validate(StringPiece ip) noexcept;
98
99 /**
100 * Create a new IPAddress instance from the provided binary data.
101 * @throws IPAddressFormatException if the input length is not 16 bytes.
102 */
103 static IPAddressV6 fromBinary(ByteRange bytes);
104
105 /**
106 * Non-throwing version of fromBinary().
107 * On failure returns IPAddressFormatError.
108 */
109 static Expected<IPAddressV6, IPAddressFormatError> tryFromBinary(
110 ByteRange bytes) noexcept;
111
112 /**
113 * Tries to create a new IPAddressV6 instance from provided string and
114 * returns it on success. Returns IPAddressFormatError on failure.
115 */
116 static Expected<IPAddressV6, IPAddressFormatError> tryFromString(
117 StringPiece str) noexcept;
118
119 /**
120 * Create a new IPAddress instance from the ip6.arpa representation.
121 * @throws IPAddressFormatException if the input is not a valid ip6.arpa
122 * representation
123 */
124 static IPAddressV6 fromInverseArpaName(const std::string& arpaname);
125
126 /**
127 * Returns the address as a Range.
128 */
129 ByteRange toBinary() const {
130 return ByteRange((const unsigned char*)&addr_.in6Addr_.s6_addr, 16);
131 }
132
133 /**
134 * Default constructor for IPAddressV6.
135 *
136 * The address value will be ::0
137 */
138 IPAddressV6();
139
140 // Create an IPAddressV6 from a string
141 // @throws IPAddressFormatException
142 //
143 explicit IPAddressV6(StringPiece ip);
144
145 // ByteArray16 constructor
146 explicit IPAddressV6(const ByteArray16& src) noexcept;
147
148 // in6_addr constructor
149 explicit IPAddressV6(const in6_addr& src) noexcept;
150
151 // sockaddr_in6 constructor
152 explicit IPAddressV6(const sockaddr_in6& src) noexcept;
153
154 /**
155 * Create a link-local IPAddressV6 from the specified ethernet MAC address.
156 */
157 IPAddressV6(LinkLocalTag tag, MacAddress mac);
158
159 // return the mapped V4 address
160 // @throws IPAddressFormatException if !isIPv4Mapped
161 IPAddressV4 createIPv4() const;
162
163 /**
164 * Return a V4 address if this is a 6To4 address.
165 * @throws TypeError if not a 6To4 address
166 */
167 IPAddressV4 getIPv4For6To4() const;
168
169 // Return true if a 6TO4 address
170 bool is6To4() const {
171 return type() == IPAddressV6::Type::T6TO4;
172 }
173
174 // Return true if a TEREDO address
175 bool isTeredo() const {
176 return type() == IPAddressV6::Type::TEREDO;
177 }
178
179 // return true if this is v4-to-v6-mapped
180 bool isIPv4Mapped() const;
181
182 // Return the V6 address type
183 Type type() const;
184
185 /**
186 * @see IPAddress#bitCount
187 * @returns 128
188 */
189 static constexpr size_t bitCount() {
190 return 128;
191 }
192
193 /**
194 * @see IPAddress#toJson
195 */
196 std::string toJson() const;
197
198 size_t hash() const;
199
200 // @see IPAddress#inSubnet
201 // @throws IPAddressFormatException if string doesn't contain a V6 address
202 bool inSubnet(StringPiece cidrNetwork) const;
203
204 // return true if address is in subnet
205 bool inSubnet(const IPAddressV6& subnet, uint8_t cidr) const {
206 return inSubnetWithMask(subnet, fetchMask(cidr));
207 }
208 bool inSubnetWithMask(const IPAddressV6& subnet, const ByteArray16& mask)
209 const;
210
211 // @see IPAddress#isLoopback
212 bool isLoopback() const;
213
214 // @see IPAddress#isNonroutable
215 bool isNonroutable() const {
216 return !isRoutable();
217 }
218
219 /**
220 * Return true if this address is routable.
221 */
222 bool isRoutable() const;
223
224 // @see IPAddress#isPrivate
225 bool isPrivate() const;
226
227 /**
228 * Return true if this is a link-local IPv6 address.
229 *
230 * Note that this only returns true for addresses in the fe80::/10 range.
231 * It returns false for the loopback address (::1), even though this address
232 * is also effectively has link-local scope. It also returns false for
233 * link-scope and interface-scope multicast addresses.
234 */
235 bool isLinkLocal() const;
236
237 /**
238 * Return the mac address if this is a link-local IPv6 address.
239 *
240 * @return an Optional<MacAddress> union representing the mac address.
241 *
242 * If the address is not a link-local one it will return an empty Optional.
243 * You can use Optional::value() to check whether the mac address is not null.
244 */
245 Optional<MacAddress> getMacAddressFromLinkLocal() const;
246
247 /**
248 * Return the mac address if this is an auto-configured IPv6 address based on
249 * EUI-64
250 *
251 * @return an Optional<MacAddress> union representing the mac address.
252 * If the address is not based on EUI-64 it will return an empty Optional.
253 * You can use Optional::value() to check whether the mac address is not null.
254 */
255 Optional<MacAddress> getMacAddressFromEUI64() const;
256
257 /**
258 * Return true if this is a multicast address.
259 */
260 bool isMulticast() const;
261
262 /**
263 * Return the flags for a multicast address.
264 * This method may only be called on multicast addresses.
265 */
266 uint8_t getMulticastFlags() const;
267
268 /**
269 * Return the scope for a multicast address.
270 * This method may only be called on multicast addresses.
271 */
272 uint8_t getMulticastScope() const;
273
274 // @see IPAddress#isZero
275 bool isZero() const {
276 constexpr auto zero = ByteArray16{{}};
277 return 0 == std::memcmp(bytes(), zero.data(), zero.size());
278 }
279
280 bool isLinkLocalBroadcast() const;
281
282 // @see IPAddress#mask
283 IPAddressV6 mask(size_t numBits) const;
284
285 // return underlying in6_addr structure
286 in6_addr toAddr() const {
287 return addr_.in6Addr_;
288 }
289
290 uint16_t getScopeId() const {
291 return scope_;
292 }
293 void setScopeId(uint16_t scope) {
294 scope_ = scope;
295 }
296
297 sockaddr_in6 toSockAddr() const {
298 sockaddr_in6 addr;
299 memset(&addr, 0, sizeof(sockaddr_in6));
300 addr.sin6_family = AF_INET6;
301 addr.sin6_scope_id = scope_;
302 memcpy(&addr.sin6_addr, &addr_.in6Addr_, sizeof(in6_addr));
303 return addr;
304 }
305
306 ByteArray16 toByteArray() const {
307 ByteArray16 ba{{0}};
308 std::memcpy(ba.data(), bytes(), 16);
309 return ba;
310 }
311
312 // @see IPAddress#toFullyQualified
313 std::string toFullyQualified() const;
314
315 // @see IPAddress#toFullyQualifiedAppend
316 void toFullyQualifiedAppend(std::string& out) const;
317
318 std::string toInverseArpaName() const;
319
320 // @see IPAddress#str
321 std::string str() const;
322
323 // @see IPAddress#version
324 uint8_t version() const {
325 return 6;
326 }
327
328 /**
329 * Return the solicited-node multicast address for this address.
330 */
331 IPAddressV6 getSolicitedNodeAddress() const;
332
333 /**
334 * Return the mask associated with the given number of bits.
335 * If for instance numBits was 24 (e.g. /24) then the V4 mask returned should
336 * be {0xff, 0xff, 0xff, 0x00}.
337 * @param [in] numBits bitmask to retrieve
338 * @throws abort if numBits == 0 or numBits > bitCount()
339 * @return mask associated with numBits
340 */
341 static const ByteArray16 fetchMask(size_t numBits);
342 // Given 2 IPAddressV6,mask pairs extract the longest common IPAddress,
343 // mask pair
344 static CIDRNetworkV6 longestCommonPrefix(
345 const CIDRNetworkV6& one,
346 const CIDRNetworkV6& two);
347 // Number of bytes in the address representation.
348 static constexpr size_t byteCount() {
349 return 16;
350 }
351
352 // get nth most significant bit - 0 indexed
353 bool getNthMSBit(size_t bitIndex) const {
354 return detail::getNthMSBitImpl(*this, bitIndex, AF_INET6);
355 }
356 // get nth most significant byte - 0 indexed
357 uint8_t getNthMSByte(size_t byteIndex) const;
358 // get nth bit - 0 indexed
359 bool getNthLSBit(size_t bitIndex) const {
360 return getNthMSBit(bitCount() - bitIndex - 1);
361 }
362 // get nth byte - 0 indexed
363 uint8_t getNthLSByte(size_t byteIndex) const {
364 return getNthMSByte(byteCount() - byteIndex - 1);
365 }
366
367 const unsigned char* bytes() const {
368 return addr_.in6Addr_.s6_addr;
369 }
370
371 protected:
372 /**
373 * Helper that returns true if the address is in the binary subnet specified
374 * by addr.
375 */
376 bool inBinarySubnet(const std::array<uint8_t, 2> addr, size_t numBits) const;
377
378 private:
379 auto tie() const {
380 return std::tie(addr_.bytes_, scope_);
381 }
382
383 public:
384 friend inline bool operator==(const IPAddressV6& a, const IPAddressV6& b) {
385 return a.tie() == b.tie();
386 }
387 friend inline bool operator!=(const IPAddressV6& a, const IPAddressV6& b) {
388 return a.tie() != b.tie();
389 }
390 friend inline bool operator<(const IPAddressV6& a, const IPAddressV6& b) {
391 return a.tie() < b.tie();
392 }
393 friend inline bool operator>(const IPAddressV6& a, const IPAddressV6& b) {
394 return a.tie() > b.tie();
395 }
396 friend inline bool operator<=(const IPAddressV6& a, const IPAddressV6& b) {
397 return a.tie() <= b.tie();
398 }
399 friend inline bool operator>=(const IPAddressV6& a, const IPAddressV6& b) {
400 return a.tie() >= b.tie();
401 }
402
403 private:
404 union AddressStorage {
405 in6_addr in6Addr_;
406 ByteArray16 bytes_;
407 AddressStorage() {
408 std::memset(this, 0, sizeof(AddressStorage));
409 }
410 explicit AddressStorage(const ByteArray16& bytes) : bytes_(bytes) {}
411 explicit AddressStorage(const in6_addr& addr) : in6Addr_(addr) {}
412 explicit AddressStorage(MacAddress mac);
413 } addr_;
414
415 // Link-local scope id. This should always be 0 for IPAddresses that
416 // are *not* link-local.
417 uint16_t scope_{0};
418
419 /**
420 * Set the current IPAddressV6 object to have the address specified by bytes.
421 * Returns IPAddressFormatError if bytes.size() is not 16.
422 */
423 Expected<Unit, IPAddressFormatError> trySetFromBinary(
424 ByteRange bytes) noexcept;
425};
426
427// boost::hash uses hash_value() so this allows boost::hash to work
428// automatically for IPAddressV6
429std::size_t hash_value(const IPAddressV6& addr);
430std::ostream& operator<<(std::ostream& os, const IPAddressV6& addr);
431// Define toAppend() to allow IPAddressV6 to be used with to<string>
432void toAppend(IPAddressV6 addr, std::string* result);
433void toAppend(IPAddressV6 addr, fbstring* result);
434
435} // namespace folly
436
437namespace std {
438template <>
439struct hash<folly::IPAddressV6> {
440 size_t operator()(const folly::IPAddressV6& addr) const {
441 return addr.hash();
442 }
443};
444} // namespace std
445