# packet.cpp

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    00001 /* $Id$ */
    00002
    00003 /*
    00004  * This file is part of OpenTTD.
    00005  * 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.
    00006  * 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.
    00007  * 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/>.
    00008  */
    00009
    00014 #ifdef ENABLE_NETWORK
    00015
    00016 #include "../../stdafx.h"
    00017 #include "../../string_func.h"
    00018
    00019 #include "packet.h"
    00020
    00025 Packet::Packet(NetworkSocketHandler *cs)
    00026 {
    00027   assert(cs != NULL);
    00028
    00029   this->cs     = cs;
    00030   this->next   = NULL;
    00031   this->pos    = 0; // We start reading from here
    00032   this->size   = 0;
    00033   this->buffer = MallocT<byte>(SEND_MTU);
    00034 }
    00035
    00040 Packet::Packet(PacketType type)
    00041 {
    00042   this->cs                   = NULL;
    00043   this->next                 = NULL;
    00044
    00045   /* Skip the size so we can write that in before sending the packet */
    00046   this->pos                  = 0;
    00047   this->size                 = sizeof(PacketSize);
    00048   this->buffer               = MallocT<byte>(SEND_MTU);
    00049   this->buffer[this->size++] = type;
    00050 }
    00051
    00055 Packet::~Packet()
    00056 {
    00057   free(this->buffer);
    00058 }
    00059
    00063 void Packet::PrepareToSend()
    00064 {
    00065   assert(this->cs == NULL && this->next == NULL);
    00066
    00067   this->buffer[0] = GB(this->size, 0, 8);
    00068   this->buffer[1] = GB(this->size, 8, 8);
    00069
    00070   this->pos  = 0; // We start reading from here
    00071 }
    00072
    00085 void Packet::Send_bool(bool data)
    00086 {
    00087   this->Send_uint8(data ? 1 : 0);
    00088 }
    00089
    00090 void Packet::Send_uint8(uint8 data)
    00091 {
    00092   assert(this->size < SEND_MTU - sizeof(data));
    00093   this->buffer[this->size++] = data;
    00094 }
    00095
    00096 void Packet::Send_uint16(uint16 data)
    00097 {
    00098   assert(this->size < SEND_MTU - sizeof(data));
    00099   this->buffer[this->size++] = GB(data, 0, 8);
    00100   this->buffer[this->size++] = GB(data, 8, 8);
    00101 }
    00102
    00103 void Packet::Send_uint32(uint32 data)
    00104 {
    00105   assert(this->size < SEND_MTU - sizeof(data));
    00106   this->buffer[this->size++] = GB(data,  0, 8);
    00107   this->buffer[this->size++] = GB(data,  8, 8);
    00108   this->buffer[this->size++] = GB(data, 16, 8);
    00109   this->buffer[this->size++] = GB(data, 24, 8);
    00110 }
    00111
    00112 void Packet::Send_uint64(uint64 data)
    00113 {
    00114   assert(this->size < SEND_MTU - sizeof(data));
    00115   this->buffer[this->size++] = GB(data,  0, 8);
    00116   this->buffer[this->size++] = GB(data,  8, 8);
    00117   this->buffer[this->size++] = GB(data, 16, 8);
    00118   this->buffer[this->size++] = GB(data, 24, 8);
    00119   this->buffer[this->size++] = GB(data, 32, 8);
    00120   this->buffer[this->size++] = GB(data, 40, 8);
    00121   this->buffer[this->size++] = GB(data, 48, 8);
    00122   this->buffer[this->size++] = GB(data, 56, 8);
    00123 }
    00124
    00130 void Packet::Send_string(const char *data)
    00131 {
    00132   assert(data != NULL);
    00133   /* The <= *is* valid due to the fact that we are comparing sizes and not the index. */
    00134   assert(this->size + strlen(data) + 1 <= SEND_MTU);
    00135   while ((this->buffer[this->size++] = *data++) != '\0') {}
    00136 }
    00137
    00138
    00147 bool Packet::CanReadFromPacket(uint bytes_to_read)
    00148 {
    00149   /* Don't allow reading from a quit client/client who send bad data */
    00150   if (this->cs->HasClientQuit()) return false;
    00151
    00152   /* Check if variable is within packet-size */
    00153   if (this->pos + bytes_to_read > this->size) {
    00154     this->cs->NetworkSocketHandler::CloseConnection();
    00155     return false;
    00156   }
    00157
    00158   return true;
    00159 }
    00160
    00164 void Packet::ReadRawPacketSize()
    00165 {
    00166   assert(this->cs != NULL && this->next == NULL);
    00167   this->size  = (PacketSize)this->buffer[0];
    00168   this->size += (PacketSize)this->buffer[1] << 8;
    00169 }
    00170
    00174 void Packet::PrepareToRead()
    00175 {
    00176   this->ReadRawPacketSize();
    00177
    00178   /* Put the position on the right place */
    00179   this->pos = sizeof(PacketSize);
    00180 }
    00181
    00182 bool Packet::Recv_bool()
    00183 {
    00184   return this->Recv_uint8() != 0;
    00185 }
    00186
    00187 uint8 Packet::Recv_uint8()
    00188 {
    00189   uint8 n;
    00190
    00191   if (!this->CanReadFromPacket(sizeof(n))) return 0;
    00192
    00193   n = this->buffer[this->pos++];
    00194   return n;
    00195 }
    00196
    00197 uint16 Packet::Recv_uint16()
    00198 {
    00199   uint16 n;
    00200
    00201   if (!this->CanReadFromPacket(sizeof(n))) return 0;
    00202
    00203   n  = (uint16)this->buffer[this->pos++];
    00204   n += (uint16)this->buffer[this->pos++] << 8;
    00205   return n;
    00206 }
    00207
    00208 uint32 Packet::Recv_uint32()
    00209 {
    00210   uint32 n;
    00211
    00212   if (!this->CanReadFromPacket(sizeof(n))) return 0;
    00213
    00214   n  = (uint32)this->buffer[this->pos++];
    00215   n += (uint32)this->buffer[this->pos++] << 8;
    00216   n += (uint32)this->buffer[this->pos++] << 16;
    00217   n += (uint32)this->buffer[this->pos++] << 24;
    00218   return n;
    00219 }
    00220
    00221 uint64 Packet::Recv_uint64()
    00222 {
    00223   uint64 n;
    00224
    00225   if (!this->CanReadFromPacket(sizeof(n))) return 0;
    00226
    00227   n  = (uint64)this->buffer[this->pos++];
    00228   n += (uint64)this->buffer[this->pos++] << 8;
    00229   n += (uint64)this->buffer[this->pos++] << 16;
    00230   n += (uint64)this->buffer[this->pos++] << 24;
    00231   n += (uint64)this->buffer[this->pos++] << 32;
    00232   n += (uint64)this->buffer[this->pos++] << 40;
    00233   n += (uint64)this->buffer[this->pos++] << 48;
    00234   n += (uint64)this->buffer[this->pos++] << 56;
    00235   return n;
    00236 }
    00237
    00239 void Packet::Recv_string(char *buffer, size_t size, bool allow_newlines)
    00240 {
    00241   PacketSize pos;
    00242   char *bufp = buffer;
    00243   const char *last = buffer + size - 1;
    00244
    00245   /* Don't allow reading from a closed socket */
    00246   if (cs->HasClientQuit()) return;
    00247
    00248   pos = this->pos;
    00249   while (--size > 0 && pos < this->size && (*buffer++ = this->buffer[pos++]) != '\0') {}
    00250
    00251   if (size == 0 || pos == this->size) {
    00252     *buffer = '\0';
    00253     /* If size was sooner to zero then the string in the stream
    00254      *  skip till the \0, so than packet can be read out correctly for the rest */
    00255     while (pos < this->size && this->buffer[pos] != '\0') pos++;
    00256     pos++;
    00257   }
    00258   this->pos = pos;
    00259
    00260   str_validate(bufp, last, allow_newlines);
    00261 }
    00262
    00263 #endif /* ENABLE_NETWORK */