TelnetServer.cpp

00001 /*
00002     Original autor: Francisco
00003     Modificacao do uso da rede: rebonatto
00004 */
00005 
00006 
00007 #include "TelnetServer.h"
00008 
00009 #include "Split.h"
00010 
00011 #define OPT_WILL    251
00012 #define OPT_WONT    252
00013 #define OPT_DO      253
00014 #define OPT_DONT    254
00015 
00016 char* welcome_msg = "Protegemed - welcome to telnet\r\nType 'help' for a list of commands\r\n";
00017 char* prompt_msg = "\r\n$ ";
00018 char iac_will_echo[] = {0xFF,0xFB,0x01};
00019 char erase_cmd[] = { 0x1B,0x5B,0x44,0x1B,0x5B,0x4B};
00020 
00021 const struct telnet_cmd_handler TelnetServer::cmds[] = {
00022         {"exit",(cmd_function)-1},
00023         {"help",TelnetServer::HelpCommand},
00024         {"reset",TelnetServer::ResetCommand},
00025         {"remove",TelnetServer::RemoveCommand},
00026         {"listparam",TelnetServer::ListParamCommand},
00027         {"getparam",TelnetServer::GetParamCommand},
00028         {"setparam",TelnetServer::SetParamCommand},
00029         {"version",TelnetServer::VersionCommand},
00030         {"update",TelnetServer::UpdateCommand},
00031         {"",(cmd_function)0}
00032 };
00033 
00034 void TelnetServer::TelnetServer_Thread(void const* arg)
00035 {
00036     int r=0;
00037     printf("Telnet Thread starting... \r\nCommands up to 100 chars\n");
00038     
00039     TCPSocketServer server;                     
00040     
00041     server.bind(23);
00042     server.listen();
00043     
00044     while(1)
00045     {
00046         TCPSocketConnection* conn ;
00047         TCPSocketConnection aux;
00048         r = server.accept(aux);
00049         conn = &aux;
00050         printf("Aceitou conexao \n");
00051         if (r != 0){
00052             printf("Error in connection\n");
00053             exit(1);
00054         }            
00055         
00056         TelnetSession(conn);
00057         printf("Fechou\n");
00058         conn->close();
00059     }
00060 }
00061 
00062 void TelnetServer::TelnetSession(TCPSocketConnection *conn)
00063 {
00064     int r;
00065     int buffer_ptr=0;   
00066 
00067     printf("Connected to %s:%d\n",conn->get_address(),conn->get_port());            
00068     
00069     conn->send(welcome_msg,strlen(welcome_msg));
00070     conn->send(prompt_msg,strlen(prompt_msg));
00071     
00072     conn->set_blocking(true);
00073     
00074     while(1)
00075     {
00076         char buf_rec[260];
00077         unsigned char buf[260];
00078         char buffer[260];             
00079         
00080         //printf("Vai recevber\n");
00081         r = conn->receive(buf_rec, strlen(buf_rec) );
00082         
00083         /* need memcpy becouse commands are ready to unsigned char and tcp receive char */
00084         memcpy(buf, buf_rec, r);
00085         
00086         //printf("Receive %d\n", r);
00087         
00088         if(r == -1)
00089         {
00090             printf("Error %d %s\n", r, buf);
00091             break;
00092         }
00093         
00094         if (r > 120){
00095             printf("Max command length = 100 chars\n");
00096             //send
00097             break;        
00098         }                
00099                 
00100         //printf("Got Here\n");        
00101         
00102         for(int i=0;i<r;i++)
00103         {
00104             //check if it is a printable or any of the line control chars
00105             if((buf[i]>31 && buf[i] < 128) || buf[i]=='\r' || buf[i]=='\n' || buf[i]=='\t')
00106             {
00107                 //append to the buffer                
00108                 buffer[buffer_ptr] = buf[i];
00109                 buffer_ptr++;
00110             }
00111             else if(buf[i] == '\b')  //backspace
00112             {
00113                 //erases the character from the command buffer
00114                 if(buffer_ptr > 0)
00115                 {
00116                     buffer_ptr--;
00117                 }
00118                 //resets m variable state (will not cause error on the next block of code
00119                 
00120             }
00121             else if((int)buf[i] == 255)   //IAC - Interpret As Command
00122             {
00123                 if((int)buf[i+1] >= 251)
00124                 {
00125                     option_negotiator(conn,buf[i+1],buf[i+2]);
00126                     i+=2;
00127                 }
00128                 else
00129                     i+=1;
00130             }
00131         }                
00132         
00133         //detect a carriage return and line feed sequence. Trigger command processor
00134         if(buffer_ptr >= 2)
00135         {
00136             if(buffer[buffer_ptr-1] == '\n' && buffer[buffer_ptr-2] == '\r')
00137             {
00138                 char **command;
00139                 int command_count;
00140 
00141                 buffer[buffer_ptr-2] = '\0';
00142                 command_count = split((char*)buffer," ",&command);
00143                 
00144                 printf("Command found: %s\n", command[0]);
00145 
00146                 //must find a function in the table and then execute it, passing the command array as an argument
00147                 for(int i=0;cmds[i].pfn != 0;i++)
00148                 {
00149                     if(!strcasecmp(command[0],cmds[i].command_name))
00150                     {
00151                         if((int)cmds[i].pfn == -1)//exit cmd
00152                         {
00153                             //delete buffer;                            
00154                             return;
00155                         }
00156                         else
00157                         {
00158                             cmds[i].pfn(conn,command,command_count);
00159                             break;
00160                         }
00161                     }
00162                 }
00163 
00164                 //write the prompt
00165                 conn->send(prompt_msg,strlen(prompt_msg));
00166                 buffer_ptr=0;
00167             }
00168         }
00169     }
00170     //delete buffer;
00171 }
00172 
00173 void TelnetServer::option_negotiator(TCPSocketConnection *conn,unsigned char opt_cmd,unsigned char opt_param)
00174 {
00175     char opt[3]={0,0,0};    
00176 
00177     if(opt_param == 1 && (opt_cmd == OPT_DO || opt_cmd == OPT_DONT))    //response for our will echo
00178     {
00179         printf("HERE");
00180         return;
00181     }
00182     if(opt_cmd == OPT_DO)   //every other option that it will ask to us to do, we won't
00183     {
00184         opt[0] = 255;
00185         opt[1] = OPT_WONT;
00186         opt[2] = opt_param;
00187         conn->send(opt,3);
00188     }
00189     else if(opt_cmd == OPT_WILL && opt_param==3)    //OK to supperss go ahead
00190     {
00191         opt[0] = 255;
00192         opt[1] = OPT_DO;
00193         opt[2] = opt_param;
00194         conn->send(opt,3);
00195     }
00196     else if(opt_cmd == OPT_WILL)    //every other option that it will ask do, we don't
00197     {
00198         opt[0] = 255;
00199         opt[1] = OPT_DONT;
00200         opt[2] = opt_param;
00201         conn->send(opt,3);
00202         
00203     }
00204 
00205 }
00206