1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4//
5// Some helpers for quic.
6
7#ifndef NET_QUIC_QUIC_UTILS_H_
8#define NET_QUIC_QUIC_UTILS_H_
9
10#include "net/base/int128.h"
11#include "net/base/net_export.h"
12#include "net/quic/quic_protocol.h"
13
14namespace net {
15
16class NET_EXPORT_PRIVATE QuicUtils {
17 public:
18  enum Priority {
19    LOCAL_PRIORITY,
20    PEER_PRIORITY,
21  };
22
23  // Returns the 64 bit FNV1a hash of the data.  See
24  // http://www.isthe.com/chongo/tech/comp/fnv/index.html#FNV-param
25  static uint64 FNV1a_64_Hash(const char* data, int len);
26
27  // returns the 128 bit FNV1a hash of the data.  See
28  // http://www.isthe.com/chongo/tech/comp/fnv/index.html#FNV-param
29  static uint128 FNV1a_128_Hash(const char* data, int len);
30
31  // FindMutualTag sets |out_result| to the first tag in the priority list that
32  // is also in the other list and returns true. If there is no intersection it
33  // returns false.
34  //
35  // Which list has priority is determined by |priority|.
36  //
37  // If |out_index| is non-NULL and a match is found then the index of that
38  // match in |their_tags| is written to |out_index|.
39  static bool FindMutualTag(const QuicTagVector& our_tags,
40                            const QuicTag* their_tags,
41                            size_t num_their_tags,
42                            Priority priority,
43                            QuicTag* out_result,
44                            size_t* out_index);
45
46  // SerializeUint128 writes |v| in little-endian form to |out|.
47  static void SerializeUint128(uint128 v, uint8* out);
48
49  // SerializeUint128 writes the first 96 bits of |v| in little-endian form
50  // to |out|.
51  static void SerializeUint128Short(uint128 v, uint8* out);
52
53  // Returns the name of the QuicRstStreamErrorCode as a char*
54  static const char* StreamErrorToString(QuicRstStreamErrorCode error);
55
56  // Returns the name of the QuicErrorCode as a char*
57  static const char* ErrorToString(QuicErrorCode error);
58
59  // Returns the level of encryption as a char*
60  static const char* EncryptionLevelToString(EncryptionLevel level);
61
62  // Returns TransmissionType as a char*
63  static const char* TransmissionTypeToString(TransmissionType type);
64
65  // TagToString is a utility function for pretty-printing handshake messages
66  // that converts a tag to a string. It will try to maintain the human friendly
67  // name if possible (i.e. kABCD -> "ABCD"), or will just treat it as a number
68  // if not.
69  static std::string TagToString(QuicTag tag);
70
71  // Given a binary buffer, return a hex+ASCII dump in the style of
72  // tcpdump's -X and -XX options:
73  // "0x0000:  0090 69bd 5400 000d 610f 0189 0800 4500  ..i.T...a.....E.\n"
74  // "0x0010:  001c fb98 4000 4001 7e18 d8ef 2301 455d  ....@.@.~...#.E]\n"
75  // "0x0020:  7fe2 0800 6bcb 0bc6 806e                 ....k....n\n"
76  static std::string StringToHexASCIIDump(base::StringPiece in_buffer);
77
78  static char* AsChars(unsigned char* data) {
79    return reinterpret_cast<char*>(data);
80  }
81
82  static QuicPriority LowestPriority();
83
84  static QuicPriority HighestPriority();
85
86 private:
87  DISALLOW_COPY_AND_ASSIGN(QuicUtils);
88};
89
90// Utility function that returns an IOVector object wrapped around |str|.
91inline IOVector MakeIOVector(base::StringPiece str) {
92  IOVector iov;
93  iov.Append(const_cast<char*>(str.data()), str.size());
94  return iov;
95}
96
97}  // namespace net
98
99#endif  // NET_QUIC_QUIC_UTILS_H_
100