Usermode/Applications/telnetd_src/main.c

   1 /*
   2  * Acess2 Telnet Server (TCP server test case)
   3  * - By John Hodge (thePowersGang)
   4  *
   5  * main.c
   6  * - All
   7  */
   8 #include <stddef.h>
   9 #include <net.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <acess/sys.h>
  13 #include <assert.h>
  14
  15 // === TYPES ===
  16 enum eTelnetMode
  17 {
  18         MODE_DATA,
  19         MODE_IAC,
  20         MODE_WILL,
  21         MODE_WONT,
  22         MODE_DO,
  23         MODE_DONT
  24 };
  25
  26 typedef struct sClient
  27 {
  28         enum eTelnetMode        Mode;
  29          int    Socket;
  30          int    pty;
  31          int    stdin;
  32          int    stdout;
  33 } tClient;
  34
  35 // === PROTOTYPES ===
  36 void    EventLoop(void);
  37 void    Server_NewClient(int FD);
  38 void    HandleServerBoundData(tClient *Client);
  39 void    HandleClientBoundData(tClient *Client);
  40
  41 // === GLOBALS ===
  42 // --- Configuration ---
  43  int    giConfig_MaxClients = 5;
  44 // --- State ---
  45  int    giServerFD;
  46 tClient *gaClients;
  47  int    giNumClients;
  48
  49 // === CODE ===
  50 int main(int argc, char *argv[])
  51 {
  52         // TODO: Configure
  53
  54         // Initialise
  55         gaClients = calloc(giConfig_MaxClients, sizeof(tClient));
  56
  57         // Open server
  58         {
  59                 uint8_t data[16];
  60                  int    addrtype = Net_ParseAddress("10.0.2.10", data);
  61                  int    port = 23;
  62                 giServerFD = Net_OpenSocket(addrtype, data, "tcps");
  63                 _SysIOCtl(giServerFD, 4, &port);        // Set port and start listening
  64         }
  65
  66         // Event loop
  67         EventLoop();
  68
  69         return 0;
  70 }
  71
  72 static void FD_SET_MAX(fd_set *set, int fd, int *maxfd)
  73 {
  74         FD_SET(fd, set);
  75         if(*maxfd < fd) *maxfd = fd;
  76 }
  77
  78 void EventLoop(void)
  79 {
  80         fd_set  fds;
  81          int    maxfd;
  82
  83         for( ;; )
  84         {
  85                 FD_ZERO(&fds);
  86                 maxfd = 0;
  87                 // Fill select
  88                 FD_SET_MAX(&fds, giServerFD, &maxfd);
  89                 for( int i = 0; i < giConfig_MaxClients; i ++ )
  90                 {
  91                         if( gaClients[i].Socket == 0 )  continue ;
  92                         _SysDebug("Socket = %i, pty = %i",
  93                                 gaClients[i].Socket, gaClients[i].pty);
  94                         FD_SET_MAX(&fds, gaClients[i].Socket, &maxfd);
  95                         FD_SET_MAX(&fds, gaClients[i].pty,  &maxfd);
  96                 }
  97
  98                 // Select!
  99                 _SysSelect( maxfd+1, &fds, NULL, NULL, NULL, 0 );
 100
 101                 // Check events
 102                 if( FD_ISSET(giServerFD, &fds) )
 103                 {
 104                         Server_NewClient(giServerFD);
 105                 }
 106                 for( int i = 0; i < giConfig_MaxClients; i ++ )
 107                 {
 108                         if( FD_ISSET(gaClients[i].Socket, &fds) )
 109                         {
 110                                 // Handle client data
 111                                 HandleServerBoundData(&gaClients[i]);
 112                         }
 113                         if( FD_ISSET(gaClients[i].pty, &fds) )
 114                         {
 115                                 // Handle output from terminal
 116                                 HandleClientBoundData(&gaClients[i]);
 117                         }
 118                 }
 119         }
 120 }
 121
 122 void Server_NewClient(int FD)
 123 {
 124         tClient *clt = NULL;
 125
 126         // TODO: Is this done in the IPStack?
 127         if( giNumClients == giConfig_MaxClients )
 128         {
 129                 // Open, reject
 130                 _SysClose( _SysOpenChild(FD, "", OPENFLAG_READ) );
 131                 return ;
 132         }
 133
 134         // Allocate client structure and open socket
 135         for( int i = 0; i < giConfig_MaxClients; i ++ )
 136         {
 137                 if( gaClients[i].Socket == 0 ) {
 138                         clt = &gaClients[i];
 139                         break;
 140                 }
 141         }
 142         assert(clt);
 143         // Accept the connection
 144         clt->Socket = _SysOpenChild(FD, "", OPENFLAG_READ|OPENFLAG_WRITE);
 145         giNumClients ++;
 146
 147         // Create stdin/stdout
 148         // TODO: Use PTYs
 149         clt->stdin = _SysOpen("/Devices/fifo/anon", OPENFLAG_READ|OPENFLAG_WRITE);
 150         clt->stdout = _SysOpen("/Devices/fifo/anon", OPENFLAG_READ|OPENFLAG_WRITE);
 151
 152         // TODO: Arguments and envp
 153         {
 154                  int    clientfd = _SysOpen("/Devices/pts/telnetd0c", OPENFLAG_READ|OPENFLAG_WRITE);
 155                 if(clientfd < 0) {
 156                         perror("Unable to open login PTY");
 157                         _SysClose(clt->Socket);
 158                         _SysClose(clt->pty);
 159                         clt->Socket = 0;
 160                         return ;
 161                 }
 162                 int fds[3] = {clientfd, clientfd, clientfd};
 163                 const char      *argv[] = {"login", NULL};
 164                 _SysSpawn("/Acess/SBin/login", argv, argv, 3, fds, NULL);
 165         }
 166 }
 167
 168 void HandleServerBoundData(tClient *Client)
 169 {
 170         uint8_t buf[BUFSIZ];
 171         size_t  len;
 172
 173         len = _SysRead(Client->Socket, buf, BUFSIZ);
 174         if( len == 0 )  return ;
 175         if( len == -1 ) {
 176                 return ;
 177         }
 178         // handle options
 179          int    last_flush = 0;
 180         for( int i = 0; i < len; i ++ )
 181         {
 182                 switch(Client->Mode)
 183                 {
 184                 case MODE_IAC:
 185                         Client->Mode = MODE_DATA;
 186                         switch(buf[i])
 187                         {
 188                         case 240:       // End of subnegotiation parameters
 189                         case 241:       // Nop
 190                                 break;
 191                         case 242:       // SYNCH
 192                         case 243:       // NVT Break
 193                         case 244:       // Function 'IP' (Ctrl-C)
 194
 195                                 break;
 196                         case 245:       // Function 'AO'
 197                         case 246:       // Function 'AYT'
 198                         case 247:       // Function 'EC'
 199                         case 248:       // Function 'EL'
 200                         case 249:       // GA Signal
 201                         case 250:       // Subnegotation
 202                                 break;
 203                         case 251:       // WILL
 204                                 Client->Mode = MODE_WILL;
 205                                 break;
 206                         case 252:       // WONT
 207                                 Client->Mode = MODE_WILL;
 208                                 break;
 209                         case 253:       // DO
 210                                 Client->Mode = MODE_WILL;
 211                                 break;
 212                         case 254:       // DONT
 213                                 Client->Mode = MODE_WILL;
 214                                 break;
 215                         case 255:       // Literal 255
 216                                 Client->Mode = MODE_DATA;
 217                                 i --;   // hacky!
 218                                 break;
 219                         }
 220                         break;
 221                 case MODE_WILL:
 222                         _SysDebug("Option %i WILL", buf[i]);
 223                         Client->Mode = MODE_DATA;
 224                         break;
 225                 case MODE_WONT:
 226                         _SysDebug("Option %i WONT", buf[i]);
 227                         Client->Mode = MODE_DATA;
 228                         break;
 229                 case MODE_DO:
 230                         _SysDebug("Option %i DO", buf[i]);
 231                         Client->Mode = MODE_DATA;
 232                         break;
 233                 case MODE_DONT:
 234                         _SysDebug("Option %i DONT", buf[i]);
 235                         Client->Mode = MODE_DATA;
 236                         break;
 237                 case MODE_DATA:
 238                         if( buf[i] == 255 )
 239                                 Client->Mode = MODE_IAC;
 240                         else
 241                                 _SysWrite(Client->pty, buf+i, 1);
 242                         break;
 243                 }
 244         }
 245 }
 246
 247 void HandleClientBoundData(tClient *Client)
 248 {
 249         char    buf[BUFSIZ];
 250          int    len;
 251
 252         len = _SysRead(Client->pty, buf, BUFSIZ);
 253         if( len <= 0 )  return ;
 254         _SysWrite(Client->Socket, buf, len);
 255 }
 256