1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
|
// Copyright (c) 2019-2020, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
// conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
// of conditions and the following disclaimer in the documentation and/or other
// materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
// used to endorse or promote products derived from this software without specific
// prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "net/levin_base.h"
#include "int-util.h"
namespace epee
{
namespace levin
{
bucket_head2 make_header(uint32_t command, uint64_t msg_size, uint32_t flags, bool expect_response) noexcept
{
bucket_head2 head = {0};
head.m_signature = SWAP64LE(LEVIN_SIGNATURE);
head.m_have_to_return_data = expect_response;
head.m_cb = SWAP64LE(msg_size);
head.m_command = SWAP32LE(command);
head.m_protocol_version = SWAP32LE(LEVIN_PROTOCOL_VER_1);
head.m_flags = SWAP32LE(flags);
return head;
}
byte_slice make_notify(int command, epee::span<const std::uint8_t> payload)
{
const bucket_head2 head = make_header(command, payload.size(), LEVIN_PACKET_REQUEST, false);
return byte_slice{epee::as_byte_span(head), payload};
}
byte_slice make_noise_notify(const std::size_t noise_bytes)
{
static constexpr const std::uint32_t flags =
LEVIN_PACKET_BEGIN | LEVIN_PACKET_END;
if (noise_bytes < sizeof(bucket_head2))
return nullptr;
std::string buffer(noise_bytes, char(0));
const bucket_head2 head = make_header(0, noise_bytes - sizeof(bucket_head2), flags, false);
std::memcpy(std::addressof(buffer[0]), std::addressof(head), sizeof(head));
return byte_slice{std::move(buffer)};
}
byte_slice make_fragmented_notify(const byte_slice& noise_message, int command, epee::span<const std::uint8_t> payload)
{
const size_t noise_size = noise_message.size();
if (noise_size < sizeof(bucket_head2) * 2)
return nullptr;
if (payload.size() <= noise_size - sizeof(bucket_head2))
{
/* The entire message can be sent at once, and the levin binary parser
will ignore extra bytes. So just pad with zeroes and otherwise send
a "normal", not fragmented message. */
const size_t padding = noise_size - sizeof(bucket_head2) - payload.size();
const span<const uint8_t> padding_bytes{noise_message.end() - padding, padding};
const bucket_head2 head = make_header(command, noise_size - sizeof(bucket_head2), LEVIN_PACKET_REQUEST, false);
return byte_slice{as_byte_span(head), payload, padding_bytes};
}
// fragment message
const size_t payload_space = noise_size - sizeof(bucket_head2);
const size_t expected_fragments = ((payload.size() - 2) / payload_space) + 1;
std::string buffer{};
buffer.reserve((expected_fragments + 1) * noise_size); // +1 here overselects for internal bucket_head2 value
bucket_head2 head = make_header(0, noise_size - sizeof(bucket_head2), LEVIN_PACKET_BEGIN, false);
buffer.append(reinterpret_cast<const char*>(&head), sizeof(head));
head.m_command = command;
head.m_flags = LEVIN_PACKET_REQUEST;
head.m_cb = payload.size();
buffer.append(reinterpret_cast<const char*>(&head), sizeof(head));
size_t copy_size = payload.remove_prefix(payload_space - sizeof(bucket_head2));
buffer.append(reinterpret_cast<const char*>(payload.data()) - copy_size, copy_size);
head.m_command = 0;
head.m_flags = 0;
head.m_cb = noise_size - sizeof(bucket_head2);
while (!payload.empty())
{
copy_size = payload.remove_prefix(payload_space);
if (payload.empty())
head.m_flags = LEVIN_PACKET_END;
buffer.append(reinterpret_cast<const char*>(&head), sizeof(head));
buffer.append(reinterpret_cast<const char*>(payload.data()) - copy_size, copy_size);
}
const size_t padding = noise_size - copy_size - sizeof(bucket_head2);
buffer.append(reinterpret_cast<const char*>(noise_message.end()) - padding, padding);
return byte_slice{std::move(buffer)};
}
} // levin
} // epee
|
