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1 /* $Id$ */ |
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2 |
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3 #ifdef ENABLE_NETWORK |
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4 |
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5 #include "../../stdafx.h" |
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6 #include "../../macros.h" |
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7 #include "../../string.h" |
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8 |
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9 #include "os_abstraction.h" |
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10 #include "config.h" |
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11 #include "packet.h" |
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12 |
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13 /** |
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14 * @file packet.h Basic functions to create, fill and read packets. |
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15 */ |
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16 |
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17 |
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18 /* Do not want to include functions.h and all required headers */ |
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19 extern void NORETURN CDECL error(const char *str, ...); |
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20 |
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21 |
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22 /** |
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23 * Create a packet for sending |
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24 * @param type the of packet |
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25 * @return the newly created packet |
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26 */ |
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27 Packet *NetworkSend_Init(PacketType type) |
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28 { |
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29 Packet *packet = malloc(sizeof(Packet)); |
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30 /* An error is inplace here, because it simply means we ran out of memory. */ |
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31 if (packet == NULL) error("Failed to allocate Packet"); |
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32 |
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33 /* Skip the size so we can write that in before sending the packet */ |
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34 packet->size = sizeof(packet->size); |
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35 packet->buffer[packet->size++] = type; |
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36 packet->pos = 0; |
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37 |
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38 return packet; |
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39 } |
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40 |
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41 /** |
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42 * Writes the packet size from the raw packet from packet->size |
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43 * @param packet the packet to write the size of |
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44 */ |
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45 void NetworkSend_FillPacketSize(Packet *packet) |
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46 { |
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47 packet->buffer[0] = GB(packet->size, 0, 8); |
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48 packet->buffer[1] = GB(packet->size, 8, 8); |
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49 } |
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50 |
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51 /** |
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52 * The next couple of functions make sure we can send |
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53 * uint8, uint16, uint32 and uint64 endian-safe |
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54 * over the network. The least significant bytes are |
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55 * sent first. |
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56 * |
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57 * So 0x01234567 would be sent as 67 45 23 01. |
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58 */ |
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59 |
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60 void NetworkSend_uint8(Packet *packet, uint8 data) |
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61 { |
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62 assert(packet->size < sizeof(packet->buffer) - sizeof(data)); |
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63 packet->buffer[packet->size++] = data; |
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64 } |
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65 |
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66 void NetworkSend_uint16(Packet *packet, uint16 data) |
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67 { |
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68 assert(packet->size < sizeof(packet->buffer) - sizeof(data)); |
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69 packet->buffer[packet->size++] = GB(data, 0, 8); |
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70 packet->buffer[packet->size++] = GB(data, 8, 8); |
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71 } |
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72 |
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73 void NetworkSend_uint32(Packet *packet, uint32 data) |
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74 { |
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75 assert(packet->size < sizeof(packet->buffer) - sizeof(data)); |
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76 packet->buffer[packet->size++] = GB(data, 0, 8); |
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77 packet->buffer[packet->size++] = GB(data, 8, 8); |
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78 packet->buffer[packet->size++] = GB(data, 16, 8); |
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79 packet->buffer[packet->size++] = GB(data, 24, 8); |
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80 } |
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81 |
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82 void NetworkSend_uint64(Packet *packet, uint64 data) |
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83 { |
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84 assert(packet->size < sizeof(packet->buffer) - sizeof(data)); |
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85 packet->buffer[packet->size++] = GB(data, 0, 8); |
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86 packet->buffer[packet->size++] = GB(data, 8, 8); |
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87 packet->buffer[packet->size++] = GB(data, 16, 8); |
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88 packet->buffer[packet->size++] = GB(data, 24, 8); |
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89 packet->buffer[packet->size++] = GB(data, 32, 8); |
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90 packet->buffer[packet->size++] = GB(data, 40, 8); |
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91 packet->buffer[packet->size++] = GB(data, 48, 8); |
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92 packet->buffer[packet->size++] = GB(data, 56, 8); |
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93 } |
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94 |
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95 /** |
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96 * Sends a string over the network. It sends out |
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97 * the string + '\0'. No size-byte or something. |
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98 */ |
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99 void NetworkSend_string(Packet *packet, const char* data) |
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100 { |
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101 assert(data != NULL); |
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102 assert(packet->size < sizeof(packet->buffer) - strlen(data) - 1); |
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103 while ((packet->buffer[packet->size++] = *data++) != '\0') {} |
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104 } |
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105 |
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106 |
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107 /** |
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108 * Receiving commands |
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109 * Again, the next couple of functions are endian-safe |
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110 * see the comment before NetworkSend_uint8 for more info. |
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111 */ |
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112 |
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113 |
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114 extern uint CloseConnection(NetworkClientState *cs); |
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115 |
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116 /** Is it safe to read from the packet, i.e. didn't we run over the buffer ? */ |
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117 static inline bool CanReadFromPacket(NetworkClientState *cs, Packet *packet, uint bytes_to_read) |
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118 { |
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119 /* Don't allow reading from a closed socket */ |
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120 if (HasClientQuit(cs)) return false; |
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121 |
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122 /* Check if variable is within packet-size */ |
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123 if (packet->pos + bytes_to_read > packet->size) { |
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124 CloseConnection(cs); |
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125 return false; |
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126 } |
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127 |
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128 return true; |
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129 } |
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130 |
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131 /** |
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132 * Reads the packet size from the raw packet and stores it in the packet->size |
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133 * @param packet the packet to read the size of |
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134 */ |
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135 void NetworkRecv_ReadPacketSize(Packet *packet) |
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136 { |
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137 packet->size = (uint16)packet->buffer[0]; |
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138 packet->size += (uint16)packet->buffer[1] << 8; |
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139 } |
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140 |
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141 uint8 NetworkRecv_uint8(NetworkClientState *cs, Packet *packet) |
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142 { |
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143 uint8 n; |
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144 |
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145 if (!CanReadFromPacket(cs, packet, sizeof(n))) return 0; |
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146 |
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147 n = packet->buffer[packet->pos++]; |
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148 return n; |
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149 } |
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150 |
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151 uint16 NetworkRecv_uint16(NetworkClientState *cs, Packet *packet) |
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152 { |
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153 uint16 n; |
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154 |
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155 if (!CanReadFromPacket(cs, packet, sizeof(n))) return 0; |
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156 |
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157 n = (uint16)packet->buffer[packet->pos++]; |
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158 n += (uint16)packet->buffer[packet->pos++] << 8; |
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159 return n; |
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160 } |
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161 |
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162 uint32 NetworkRecv_uint32(NetworkClientState *cs, Packet *packet) |
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163 { |
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164 uint32 n; |
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165 |
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166 if (!CanReadFromPacket(cs, packet, sizeof(n))) return 0; |
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167 |
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168 n = (uint32)packet->buffer[packet->pos++]; |
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169 n += (uint32)packet->buffer[packet->pos++] << 8; |
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170 n += (uint32)packet->buffer[packet->pos++] << 16; |
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171 n += (uint32)packet->buffer[packet->pos++] << 24; |
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172 return n; |
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173 } |
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174 |
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175 uint64 NetworkRecv_uint64(NetworkClientState *cs, Packet *packet) |
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176 { |
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177 uint64 n; |
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178 |
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179 if (!CanReadFromPacket(cs, packet, sizeof(n))) return 0; |
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180 |
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181 n = (uint64)packet->buffer[packet->pos++]; |
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182 n += (uint64)packet->buffer[packet->pos++] << 8; |
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183 n += (uint64)packet->buffer[packet->pos++] << 16; |
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184 n += (uint64)packet->buffer[packet->pos++] << 24; |
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185 n += (uint64)packet->buffer[packet->pos++] << 32; |
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186 n += (uint64)packet->buffer[packet->pos++] << 40; |
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187 n += (uint64)packet->buffer[packet->pos++] << 48; |
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188 n += (uint64)packet->buffer[packet->pos++] << 56; |
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189 return n; |
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190 } |
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191 |
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192 /** Reads a string till it finds a '\0' in the stream */ |
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193 void NetworkRecv_string(NetworkClientState *cs, Packet *p, char *buffer, size_t size) |
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194 { |
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195 PacketSize pos; |
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196 char *bufp = buffer; |
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197 |
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198 /* Don't allow reading from a closed socket */ |
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199 if (HasClientQuit(cs)) return; |
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200 |
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201 pos = p->pos; |
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202 while (--size > 0 && pos < p->size && (*buffer++ = p->buffer[pos++]) != '\0') {} |
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203 |
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204 if (size == 0 || pos == p->size) { |
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205 *buffer = '\0'; |
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206 /* If size was sooner to zero then the string in the stream |
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207 * skip till the \0, so than packet can be read out correctly for the rest */ |
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208 while (pos < p->size && p->buffer[pos] != '\0') pos++; |
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209 pos++; |
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210 } |
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211 p->pos = pos; |
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212 |
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213 str_validate(bufp); |
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214 } |
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215 |
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216 #endif /* ENABLE_NETWORK */ |