OpenTTD Source: src/network/core/packet.h Source File

OpenTTD Source 15.0-beta1

packet.h
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1/*
2 * This file is part of OpenTTD.
3 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
4 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
5 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
6 */
7
12#ifndef NETWORK_CORE_PACKET_H
13#define NETWORK_CORE_PACKET_H
14
15#include "os_abstraction.h"
16#include "config.h"
17#include "core.h"
18#include "../../string_type.h"
19
20 typedef uint16_t PacketSize;
21 typedef uint8_t PacketType;
22
42 struct Packet {
43 static constexpr size_t EncodedLengthOfPacketSize() { return sizeof(PacketSize); }
44 static constexpr size_t EncodedLengthOfPacketType() { return sizeof(PacketType); }
45private:
47 PacketSize pos;
49 std::vector<uint8_t> buffer;
51 size_t limit;
52
54 NetworkSocketHandler *cs;
55
56public:
57 Packet(NetworkSocketHandler *cs, size_t limit, size_t initial_read_size = EncodedLengthOfPacketSize());
58 Packet(NetworkSocketHandler *cs, PacketType type, size_t limit = COMPAT_MTU);
59
60 /* Sending/writing of packets */
61 void PrepareToSend();
62
63 bool CanWriteToPacket(size_t bytes_to_write);
64 void Send_bool (bool data);
65 void Send_uint8 (uint8_t data);
66 void Send_uint16(uint16_t data);
67 void Send_uint32(uint32_t data);
68 void Send_uint64(uint64_t data);
69 void Send_string(const std::string_view data);
70 void Send_buffer(const std::vector<uint8_t> &data);
71 std::span<const uint8_t> Send_bytes(const std::span<const uint8_t> span);
72
73 /* Reading/receiving of packets */
74 bool HasPacketSizeData() const;
75 bool ParsePacketSize();
76 size_t Size() const;
77 [[nodiscard]] bool PrepareToRead();
78 PacketType GetPacketType() const;
79
80 bool CanReadFromPacket(size_t bytes_to_read, bool close_connection = false);
81 bool Recv_bool ();
82 uint8_t Recv_uint8 ();
83 uint16_t Recv_uint16();
84 uint32_t Recv_uint32();
85 uint64_t Recv_uint64();
86 std::vector<uint8_t> Recv_buffer();
87 size_t Recv_bytes(std::span<uint8_t> span);
88 std::string Recv_string(size_t length, StringValidationSettings settings = SVS_REPLACE_WITH_QUESTION_MARK);
89
90 size_t RemainingBytesToTransfer() const;
91
104 template <
105 typename A = size_t,
106 typename F,
107 typename D,
108 typename ... Args>
109 ssize_t TransferOutWithLimit(F transfer_function, size_t limit, D destination, Args&& ... args)
110 {
111 size_t amount = std::min(this->RemainingBytesToTransfer(), limit);
112 if (amount == 0) return 0;
113
114 assert(this->pos < this->buffer.size());
115 assert(this->pos + amount <= this->buffer.size());
116 /* Making buffer a char means casting a lot in the Recv/Send functions. */
117 const char *output_buffer = reinterpret_cast<const char*>(this->buffer.data() + this->pos);
118 ssize_t bytes = transfer_function(destination, output_buffer, static_cast<A>(amount), std::forward<Args>(args)...);
119 if (bytes > 0) this->pos += bytes;
120 return bytes;
121 }
122
138 template <typename A = size_t, typename F, typename D, typename ... Args>
139 ssize_t TransferOut(F transfer_function, D destination, Args&& ... args)
140 {
141 return TransferOutWithLimit<A>(transfer_function, std::numeric_limits<size_t>::max(), destination, std::forward<Args>(args)...);
142 }
143
173 template <typename A = size_t, typename F, typename S, typename ... Args>
174 ssize_t TransferIn(F transfer_function, S source, Args&& ... args)
175 {
176 size_t amount = this->RemainingBytesToTransfer();
177 if (amount == 0) return 0;
178
179 assert(this->pos < this->buffer.size());
180 assert(this->pos + amount <= this->buffer.size());
181 /* Making buffer a char means casting a lot in the Recv/Send functions. */
182 char *input_buffer = reinterpret_cast<char*>(this->buffer.data() + this->pos);
183 ssize_t bytes = transfer_function(source, input_buffer, static_cast<A>(amount), std::forward<Args>(args)...);
184 if (bytes > 0) this->pos += bytes;
185 return bytes;
186 }
187};
188
189#endif /* NETWORK_CORE_PACKET_H */
NetworkSocketHandler
SocketHandler for all network sockets in OpenTTD.
Definition core.h:43
config.h
Configuration options of the network stuff.
COMPAT_MTU
static const size_t COMPAT_MTU
Number of bytes we can pack in a single packet for backward compatibility.
Definition config.h:46
core.h
Base for all network types (UDP and TCP)
settings
fluid_settings_t * settings
FluidSynth settings handle.
Definition fluidsynth.cpp:21
os_abstraction.h
Network stuff has many things that needs to be included and/or implemented by default.
PacketType
uint8_t PacketType
Identifier for the packet.
Definition packet.h:21
PacketSize
uint16_t PacketSize
Size of the whole packet.
Definition packet.h:20
StringValidationSettings
StringValidationSettings
Settings for the string validation.
Definition string_type.h:44
SVS_REPLACE_WITH_QUESTION_MARK
@ SVS_REPLACE_WITH_QUESTION_MARK
Replace the unknown/bad bits with question marks.
Definition string_type.h:46
Packet
Internal entity of a packet.
Definition packet.h:42
Packet::Size
size_t Size() const
Get the number of bytes in the packet.
Definition packet.cpp:250
Packet::Recv_uint16
uint16_t Recv_uint16()
Read a 16 bits integer from the packet.
Definition packet.cpp:332
Packet::TransferOutWithLimit
ssize_t TransferOutWithLimit(F transfer_function, size_t limit, D destination, Args &&... args)
Transfer data from the packet to the given function.
Definition packet.h:109
Packet::Recv_bytes
size_t Recv_bytes(std::span< uint8_t > span)
Extract at most the length of the span bytes from the packet into the span.
Definition packet.cpp:403
Packet::Recv_uint64
uint64_t Recv_uint64()
Read a 64 bits integer from the packet.
Definition packet.cpp:364
Packet::Recv_bool
bool Recv_bool()
Read a boolean from the packet.
Definition packet.cpp:309
Packet::Recv_uint32
uint32_t Recv_uint32()
Read a 32 bits integer from the packet.
Definition packet.cpp:347
Packet::cs
NetworkSocketHandler * cs
Socket we're associated with.
Definition packet.h:54
Packet::Send_bool
void Send_bool(bool data)
Package a boolean in the packet.
Definition packet.cpp:111
Packet::PrepareToRead
bool PrepareToRead()
Prepares the packet so it can be read.
Definition packet.cpp:278
Packet::GetPacketType
PacketType GetPacketType() const
Get the PacketType from this packet.
Definition packet.cpp:297
Packet::pos
PacketSize pos
The current read/write position in the packet.
Definition packet.h:47
Packet::Send_bytes
std::span< const uint8_t > Send_bytes(const std::span< const uint8_t > span)
Send as many of the bytes as possible in the packet.
Definition packet.cpp:197
Packet::limit
size_t limit
The limit for the packet size.
Definition packet.h:51
Packet::HasPacketSizeData
bool HasPacketSizeData() const
Check whether the packet, given the position of the "write" pointer, has read enough of the packet to...
Definition packet.cpp:238
Packet::Recv_uint8
uint8_t Recv_uint8()
Read a 8 bits integer from the packet.
Definition packet.cpp:318
Packet::ParsePacketSize
bool ParsePacketSize()
Reads the packet size from the raw packet and stores it in the packet->size.
Definition packet.cpp:259
Packet::buffer
std::vector< uint8_t > buffer
The buffer of this packet.
Definition packet.h:49
Packet::TransferIn
ssize_t TransferIn(F transfer_function, S source, Args &&... args)
Transfer data from the given function into the packet.
Definition packet.h:174
Packet::PrepareToSend
void PrepareToSend()
Writes the packet size from the raw packet from packet->size.
Definition packet.cpp:66
Packet::Send_uint8
void Send_uint8(uint8_t data)
Package a 8 bits integer in the packet.
Definition packet.cpp:120
Packet::RemainingBytesToTransfer
size_t RemainingBytesToTransfer() const
Get the amount of bytes that are still available for the Transfer functions.
Definition packet.cpp:447
Packet::Send_uint32
void Send_uint32(uint32_t data)
Package a 32 bits integer in the packet.
Definition packet.cpp:141
Packet::TransferOut
ssize_t TransferOut(F transfer_function, D destination, Args &&... args)
Transfer data from the packet to the given function.
Definition packet.h:139
Packet::Send_buffer
void Send_buffer(const std::vector< uint8_t > &data)
Copy a sized byte buffer into the packet.
Definition packet.cpp:183
Packet::Recv_buffer
std::vector< uint8_t > Recv_buffer()
Extract a sized byte buffer from the packet.
Definition packet.cpp:385
Packet::Send_uint16
void Send_uint16(uint16_t data)
Package a 16 bits integer in the packet.
Definition packet.cpp:130
Packet::CanReadFromPacket
bool CanReadFromPacket(size_t bytes_to_read, bool close_connection=false)
Is it safe to read from the packet, i.e.
Definition packet.cpp:219
Packet::CanWriteToPacket
bool CanWriteToPacket(size_t bytes_to_write)
Is it safe to write to the packet, i.e.
Definition packet.cpp:90
Packet::Recv_string
std::string Recv_string(size_t length, StringValidationSettings settings=SVS_REPLACE_WITH_QUESTION_MARK)
Reads characters (bytes) from the packet until it finds a '\0', or reaches a maximum of length charac...
Definition packet.cpp:425
Packet::Send_string
void Send_string(const std::string_view data)
Sends a string over the network.
Definition packet.cpp:172
Packet::Send_uint64
void Send_uint64(uint64_t data)
Package a 64 bits integer in the packet.
Definition packet.cpp:154