1 /*
2  * Copyright (c) Facebook, Inc. and its affiliates.
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 
25 #include <folly/Expected.h>
26 #include <folly/FBString.h>
27 #include <folly/IPAddressException.h>
28 #include <folly/Range.h>
29 #include <folly/detail/IPAddress.h>
30 #include <folly/hash/Hash.h>
31 
32 #ifdef __XROS__
33 #include <xros/portability/third_party/include/netinet/in.h> // @manual
34 #endif
35 
36 namespace folly {
37 
38 class IPAddress;
39 class IPAddressV4;
40 class IPAddressV6;
41 
42 /**
43  * Pair of IPAddressV4, netmask
44  */
45 typedef std::pair<IPAddressV4, uint8_t> CIDRNetworkV4;
46 
47 /**
48  * Specialization for IPv4 addresses
49  */
50 typedef std::array<uint8_t, 4> ByteArray4;
51 
52 /**
53  * IPv4 variation of IPAddress.
54  *
55  * Added methods: toLong, toLongHBO and createIPv6
56  *
57  * @note toLong/fromLong deal in network byte order, use toLongHBO/fromLongHBO
58  * if working in host byte order.
59  *
60  * @see IPAddress
61  */
62 class IPAddressV4 {
63  public:
64   // Max size of std::string returned by toFullyQualified.
65   static constexpr size_t kMaxToFullyQualifiedSize =
66       4 /*words*/ * 3 /*max chars per word*/ + 3 /*separators*/;
67 
68   // returns true iff the input string can be parsed as an ipv4-address
69   static bool validate(StringPiece ip) noexcept;
70 
71   // create an IPAddressV4 instance from a uint32_t (network byte order)
72   static IPAddressV4 fromLong(uint32_t src);
73   // same as above but host byte order
74   static IPAddressV4 fromLongHBO(uint32_t src);
75 
76   /**
77    * Create a new IPAddress instance from the provided binary data.
78    * @throws IPAddressFormatException if the input length is not 4 bytes.
79    */
80   static IPAddressV4 fromBinary(ByteRange bytes);
81 
82   /**
83    * Non-throwing version of fromBinary().
84    * On failure returns IPAddressFormatError.
85    */
86   static Expected<IPAddressV4, IPAddressFormatError> tryFromBinary(
87       ByteRange bytes) noexcept;
88 
89   /**
90    * Tries to create a new IPAddressV4 instance from provided string and
91    * returns it on success. Returns IPAddressFormatError on failure.
92    */
93   static Expected<IPAddressV4, IPAddressFormatError> tryFromString(
94       StringPiece str) noexcept;
95 
96   /**
97    * Returns the address as a Range.
98    */
toBinary()99   ByteRange toBinary() const {
100     return ByteRange((const unsigned char*)&addr_.inAddr_.s_addr, 4);
101   }
102 
103   /**
104    * Create a new IPAddress instance from the in-addr.arpa representation.
105    * @throws IPAddressFormatException if the input is not a valid in-addr.arpa
106    * representation
107    */
108   static IPAddressV4 fromInverseArpaName(const std::string& arpaname);
109 
110   /**
111    * Convert a IPv4 address string to a long in network byte order.
112    * @param [in] ip the address to convert
113    * @return the long representation of the address
114    */
115   static uint32_t toLong(StringPiece ip);
116   // Same as above, but in host byte order.
117   // This is slightly slower than toLong.
118   static uint32_t toLongHBO(StringPiece ip);
119 
120   /**
121    * Default constructor for IPAddressV4.
122    *
123    * The address value will be 0.0.0.0
124    */
125   IPAddressV4();
126 
127   // Create an IPAddressV4 from a string
128   // @throws IPAddressFormatException
129   explicit IPAddressV4(StringPiece addr);
130 
131   // ByteArray4 constructor
132   explicit IPAddressV4(const ByteArray4& src) noexcept;
133 
134   // in_addr constructor
135   explicit IPAddressV4(const in_addr src) noexcept;
136 
137   // Return the V6 mapped representation of the address.
138   IPAddressV6 createIPv6() const;
139 
140   /**
141    * Return a V6 address in the format of an 6To4 address.
142    */
143   IPAddressV6 getIPv6For6To4() const;
144 
145   // Return the long (network byte order) representation of the address.
toLong()146   uint32_t toLong() const { return toAddr().s_addr; }
147 
148   // Return the long (host byte order) representation of the address.
149   // This is slightly slower than toLong.
toLongHBO()150   uint32_t toLongHBO() const { return ntohl(toLong()); }
151 
152   /**
153    * @see IPAddress#bitCount
154    * @returns 32
155    */
bitCount()156   static constexpr size_t bitCount() { return 32; }
157 
158   /**
159    * @See IPAddress#toJson
160    */
161   std::string toJson() const;
162 
hash()163   size_t hash() const {
164     static const uint32_t seed = AF_INET;
165     uint32_t hashed = hash::fnv32_buf(&addr_, 4);
166     return hash::hash_combine(seed, hashed);
167   }
168 
169   // @see IPAddress#inSubnet
170   // @throws IPAddressFormatException if string doesn't contain a V4 address
171   bool inSubnet(StringPiece cidrNetwork) const;
172 
173   // return true if address is in subnet
inSubnet(const IPAddressV4 & subnet,uint8_t cidr)174   bool inSubnet(const IPAddressV4& subnet, uint8_t cidr) const {
175     return inSubnetWithMask(subnet, fetchMask(cidr));
176   }
177   bool inSubnetWithMask(const IPAddressV4& subnet, const ByteArray4 mask) const;
178 
179   // @see IPAddress#isLoopback
180   bool isLoopback() const;
181 
182   // @see IPAddress#isLinkLocal
183   bool isLinkLocal() const;
184 
185   // @see IPAddress#isNonroutable
186   bool isNonroutable() const;
187 
188   // @see IPAddress#isPrivate
189   bool isPrivate() const;
190 
191   // @see IPAddress#isMulticast
192   bool isMulticast() const;
193 
194   // @see IPAddress#isZero
isZero()195   bool isZero() const {
196     constexpr auto zero = ByteArray4{{}};
197     return 0 == std::memcmp(bytes(), zero.data(), zero.size());
198   }
199 
isLinkLocalBroadcast()200   bool isLinkLocalBroadcast() const {
201     return (INADDR_BROADCAST == toLongHBO());
202   }
203 
204   // @see IPAddress#mask
205   IPAddressV4 mask(size_t numBits) const;
206 
207   // @see IPAddress#str
208   std::string str() const;
209 
210   std::string toInverseArpaName() const;
211 
212   // return underlying in_addr structure
toAddr()213   in_addr toAddr() const { return addr_.inAddr_; }
214 
toSockAddr()215   sockaddr_in toSockAddr() const {
216     sockaddr_in addr;
217     memset(&addr, 0, sizeof(sockaddr_in));
218     addr.sin_family = AF_INET;
219     memcpy(&addr.sin_addr, &addr_.inAddr_, sizeof(in_addr));
220     return addr;
221   }
222 
toByteArray()223   ByteArray4 toByteArray() const {
224     ByteArray4 ba{{0}};
225     std::memcpy(ba.data(), bytes(), 4);
226     return ba;
227   }
228 
229   // @see IPAddress#toFullyQualified
toFullyQualified()230   std::string toFullyQualified() const { return str(); }
231 
232   // @see IPAddress#toFullyQualifiedAppend
233   void toFullyQualifiedAppend(std::string& out) const;
234 
235   // @see IPAddress#version
version()236   uint8_t version() const { return 4; }
237 
238   /**
239    * Return the mask associated with the given number of bits.
240    * If for instance numBits was 24 (e.g. /24) then the V4 mask returned should
241    * be {0xff, 0xff, 0xff, 0x00}.
242    * @param [in] numBits bitmask to retrieve
243    * @throws abort if numBits == 0 or numBits > bitCount()
244    * @return mask associated with numBits
245    */
246   static ByteArray4 fetchMask(size_t numBits);
247 
248   // Given 2 IPAddressV4, mask pairs extract the longest common IPAddress,
249   // mask pair
250   static CIDRNetworkV4 longestCommonPrefix(
251       const CIDRNetworkV4& one, const CIDRNetworkV4& two);
252   // Number of bytes in the address representation.
byteCount()253   static size_t byteCount() { return 4; }
254   // get nth most significant bit - 0 indexed
getNthMSBit(size_t bitIndex)255   bool getNthMSBit(size_t bitIndex) const {
256     return detail::getNthMSBitImpl(*this, bitIndex, AF_INET);
257   }
258   // get nth most significant byte - 0 indexed
259   uint8_t getNthMSByte(size_t byteIndex) const;
260   // get nth bit - 0 indexed
getNthLSBit(size_t bitIndex)261   bool getNthLSBit(size_t bitIndex) const {
262     return getNthMSBit(bitCount() - bitIndex - 1);
263   }
264   // get nth byte - 0 indexed
getNthLSByte(size_t byteIndex)265   uint8_t getNthLSByte(size_t byteIndex) const {
266     return getNthMSByte(byteCount() - byteIndex - 1);
267   }
268 
bytes()269   const unsigned char* bytes() const { return addr_.bytes_.data(); }
270 
271  private:
272   union AddressStorage {
273     static_assert(
274         sizeof(in_addr) == sizeof(ByteArray4),
275         "size of in_addr and ByteArray4 are different");
276     in_addr inAddr_;
277     ByteArray4 bytes_;
AddressStorage()278     AddressStorage() { std::memset(this, 0, sizeof(AddressStorage)); }
AddressStorage(const ByteArray4 bytes)279     explicit AddressStorage(const ByteArray4 bytes) : bytes_(bytes) {}
AddressStorage(const in_addr addr)280     explicit AddressStorage(const in_addr addr) : inAddr_(addr) {}
281   } addr_;
282 
283   /**
284    * Set the current IPAddressV4 object to have the address specified by bytes.
285    * Returns IPAddressFormatError if bytes.size() is not 4.
286    */
287   Expected<Unit, IPAddressFormatError> trySetFromBinary(
288       ByteRange bytes) noexcept;
289 };
290 
291 // boost::hash uses hash_value() so this allows boost::hash to work
292 // automatically for IPAddressV4
293 size_t hash_value(const IPAddressV4& addr);
294 std::ostream& operator<<(std::ostream& os, const IPAddressV4& addr);
295 // Define toAppend() to allow IPAddressV4 to be used with to<string>
296 void toAppend(IPAddressV4 addr, std::string* result);
297 void toAppend(IPAddressV4 addr, fbstring* result);
298 
299 /**
300  * Return true if two addresses are equal.
301  */
302 inline bool operator==(const IPAddressV4& addr1, const IPAddressV4& addr2) {
303   return (addr1.toLong() == addr2.toLong());
304 }
305 // Return true if addr1 < addr2
306 inline bool operator<(const IPAddressV4& addr1, const IPAddressV4& addr2) {
307   return (addr1.toLongHBO() < addr2.toLongHBO());
308 }
309 // Derived operators
310 inline bool operator!=(const IPAddressV4& a, const IPAddressV4& b) {
311   return !(a == b);
312 }
313 inline bool operator>(const IPAddressV4& a, const IPAddressV4& b) {
314   return b < a;
315 }
316 inline bool operator<=(const IPAddressV4& a, const IPAddressV4& b) {
317   return !(a > b);
318 }
319 inline bool operator>=(const IPAddressV4& a, const IPAddressV4& b) {
320   return !(a < b);
321 }
322 
323 } // namespace folly
324 
325 namespace std {
326 template <>
327 struct hash<folly::IPAddressV4> {
328   size_t operator()(const folly::IPAddressV4 addr) const { return addr.hash(); }
329 };
330 } // namespace std
331