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