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
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
|
/* $Id$ */
#ifdef ENABLE_NETWORK
#include "../../stdafx.h"
#include "../../macros.h"
#include "../../string.h"
#include "os_abstraction.h"
#include "config.h"
#include "packet.h"
/**
* @file packet.h Basic functions to create, fill and read packets.
*/
/* Do not want to include functions.h and all required headers */
extern void NORETURN CDECL error(const char *str, ...);
/**
* Create a packet for sending
* @param type the of packet
* @return the newly created packet
*/
Packet *NetworkSend_Init(PacketType type)
{
Packet *packet = malloc(sizeof(Packet));
/* An error is inplace here, because it simply means we ran out of memory. */
if (packet == NULL) error("Failed to allocate Packet");
/* Skip the size so we can write that in before sending the packet */
packet->size = sizeof(packet->size);
packet->buffer[packet->size++] = type;
packet->pos = 0;
return packet;
}
/**
* Writes the packet size from the raw packet from packet->size
* @param packet the packet to write the size of
*/
void NetworkSend_FillPacketSize(Packet *packet)
{
packet->buffer[0] = GB(packet->size, 0, 8);
packet->buffer[1] = GB(packet->size, 8, 8);
}
/**
* The next couple of functions make sure we can send
* uint8, uint16, uint32 and uint64 endian-safe
* over the network. The least significant bytes are
* sent first.
*
* So 0x01234567 would be sent as 67 45 23 01.
*/
void NetworkSend_uint8(Packet *packet, uint8 data)
{
assert(packet->size < sizeof(packet->buffer) - sizeof(data));
packet->buffer[packet->size++] = data;
}
void NetworkSend_uint16(Packet *packet, uint16 data)
{
assert(packet->size < sizeof(packet->buffer) - sizeof(data));
packet->buffer[packet->size++] = GB(data, 0, 8);
packet->buffer[packet->size++] = GB(data, 8, 8);
}
void NetworkSend_uint32(Packet *packet, uint32 data)
{
assert(packet->size < sizeof(packet->buffer) - sizeof(data));
packet->buffer[packet->size++] = GB(data, 0, 8);
packet->buffer[packet->size++] = GB(data, 8, 8);
packet->buffer[packet->size++] = GB(data, 16, 8);
packet->buffer[packet->size++] = GB(data, 24, 8);
}
void NetworkSend_uint64(Packet *packet, uint64 data)
{
assert(packet->size < sizeof(packet->buffer) - sizeof(data));
packet->buffer[packet->size++] = GB(data, 0, 8);
packet->buffer[packet->size++] = GB(data, 8, 8);
packet->buffer[packet->size++] = GB(data, 16, 8);
packet->buffer[packet->size++] = GB(data, 24, 8);
packet->buffer[packet->size++] = GB(data, 32, 8);
packet->buffer[packet->size++] = GB(data, 40, 8);
packet->buffer[packet->size++] = GB(data, 48, 8);
packet->buffer[packet->size++] = GB(data, 56, 8);
}
/**
* Sends a string over the network. It sends out
* the string + '\0'. No size-byte or something.
*/
void NetworkSend_string(Packet *packet, const char* data)
{
assert(data != NULL);
assert(packet->size < sizeof(packet->buffer) - strlen(data) - 1);
while ((packet->buffer[packet->size++] = *data++) != '\0') {}
}
/**
* Receiving commands
* Again, the next couple of functions are endian-safe
* see the comment before NetworkSend_uint8 for more info.
*/
extern uint CloseConnection(NetworkClientState *cs);
/** Is it safe to read from the packet, i.e. didn't we run over the buffer ? */
static inline bool CanReadFromPacket(NetworkClientState *cs, Packet *packet, uint bytes_to_read)
{
/* Don't allow reading from a closed socket */
if (HasClientQuit(cs)) return false;
/* Check if variable is within packet-size */
if (packet->pos + bytes_to_read > packet->size) {
CloseConnection(cs);
return false;
}
return true;
}
/**
* Reads the packet size from the raw packet and stores it in the packet->size
* @param packet the packet to read the size of
*/
void NetworkRecv_ReadPacketSize(Packet *packet)
{
packet->size = (uint16)packet->buffer[0];
packet->size += (uint16)packet->buffer[1] << 8;
}
uint8 NetworkRecv_uint8(NetworkClientState *cs, Packet *packet)
{
uint8 n;
if (!CanReadFromPacket(cs, packet, sizeof(n))) return 0;
n = packet->buffer[packet->pos++];
return n;
}
uint16 NetworkRecv_uint16(NetworkClientState *cs, Packet *packet)
{
uint16 n;
if (!CanReadFromPacket(cs, packet, sizeof(n))) return 0;
n = (uint16)packet->buffer[packet->pos++];
n += (uint16)packet->buffer[packet->pos++] << 8;
return n;
}
uint32 NetworkRecv_uint32(NetworkClientState *cs, Packet *packet)
{
uint32 n;
if (!CanReadFromPacket(cs, packet, sizeof(n))) return 0;
n = (uint32)packet->buffer[packet->pos++];
n += (uint32)packet->buffer[packet->pos++] << 8;
n += (uint32)packet->buffer[packet->pos++] << 16;
n += (uint32)packet->buffer[packet->pos++] << 24;
return n;
}
uint64 NetworkRecv_uint64(NetworkClientState *cs, Packet *packet)
{
uint64 n;
if (!CanReadFromPacket(cs, packet, sizeof(n))) return 0;
n = (uint64)packet->buffer[packet->pos++];
n += (uint64)packet->buffer[packet->pos++] << 8;
n += (uint64)packet->buffer[packet->pos++] << 16;
n += (uint64)packet->buffer[packet->pos++] << 24;
n += (uint64)packet->buffer[packet->pos++] << 32;
n += (uint64)packet->buffer[packet->pos++] << 40;
n += (uint64)packet->buffer[packet->pos++] << 48;
n += (uint64)packet->buffer[packet->pos++] << 56;
return n;
}
/** Reads a string till it finds a '\0' in the stream */
void NetworkRecv_string(NetworkClientState *cs, Packet *p, char *buffer, size_t size)
{
PacketSize pos;
char *bufp = buffer;
/* Don't allow reading from a closed socket */
if (HasClientQuit(cs)) return;
pos = p->pos;
while (--size > 0 && pos < p->size && (*buffer++ = p->buffer[pos++]) != '\0') {}
if (size == 0 || pos == p->size) {
*buffer = '\0';
/* If size was sooner to zero then the string in the stream
* skip till the \0, so than packet can be read out correctly for the rest */
while (pos < p->size && p->buffer[pos] != '\0') pos++;
pos++;
}
p->pos = pos;
str_validate(bufp);
}
#endif /* ENABLE_NETWORK */
|
