Usermode/Applications/dhcpclient_src/main.c

   1 /*
   2  *
   3  * http://www.ietf.org/rfc/rfc2131.txt
   4  */
   5 #include <unistd.h>
   6 #include <stdint.h>
   7 #include <stdio.h>
   8 #include <string.h>
   9 #include <stdlib.h>
  10 #include <net.h>
  11 #include <acess/sys.h>
  12
  13 #define FILENAME_MAX    255
  14 // --- Translation functions ---
  15 static inline uint32_t htonl(uint32_t v)
  16 {
  17         return    (((v >> 24) & 0xFF) <<  0)
  18                 | (((v >> 16) & 0xFF) <<  8)
  19                 | (((v >>  8) & 0xFF) << 16)
  20                 | (((v >>  0) & 0xFF) << 24);
  21 }
  22 static inline uint16_t htons(uint16_t v)
  23 {
  24         return    (((v >> 8) & 0xFF) <<  0)
  25                 | (((v >> 0) & 0xFF) <<  8);
  26 }
  27 #define htonb(v)        v
  28 #define ntohl(v)        htonl(v)
  29 #define ntohs(v)        htons(v)
  30
  31 // === CONSTANTS ===
  32 enum eStates
  33 {
  34         STATE_PREINIT,
  35         STATE_DISCOVER_SENT,
  36         STATE_REQUEST_SENT,
  37         STATE_COMPLETE
  38 };
  39
  40 // === STRUCTURES ===
  41 #define DHCP_MAGIC      0x63825363
  42 struct sDHCP_Message
  43 {
  44         uint8_t op;
  45         uint8_t htype;  // 1 = Ethernet
  46         uint8_t hlen;   // 6 bytes for MAC
  47         uint8_t hops;   // Hop counting
  48         uint32_t        xid;
  49         uint16_t        secs;
  50         uint16_t        flags;
  51         uint32_t        ciaddr;
  52         uint32_t        yiaddr;
  53         uint32_t        siaddr;
  54         uint32_t        giaddr;
  55         uint8_t chaddr[16];
  56         uint8_t sname[64];
  57         uint8_t file[128];
  58         uint32_t        dhcp_magic;     // 0x63 0x82 0x53 0x63
  59         uint8_t options[];
  60 };
  61
  62 typedef struct sInterface
  63 {
  64         struct sInterface       *Next;
  65         char    *Adapter;
  66          int    State;
  67          int    Num;
  68          int    SocketFD;
  69          int    IfaceFD;
  70
  71         uint32_t        TransactionID;
  72         char    HWAddr[6];
  73
  74         int64_t Timeout;
  75 } tInterface;
  76
  77 // === PROTOTYPES ===
  78 int     main(int argc, char *argv[]);
  79 void    Scan_Dir(tInterface **IfaceList, const char *Directory);
  80 int     Start_Interface(tInterface *Iface);
  81 void    Send_DHCPDISCOVER(tInterface *Iface);
  82 void    Send_DHCPREQUEST(tInterface *Iface, void *OfferBuffer, int TypeOffset);
  83 int     Handle_Packet(tInterface *Iface);
  84 void    Handle_Timeout(tInterface *Iface);
  85 void    Update_State(tInterface *Iface, int newState);
  86 void    SetAddress(tInterface *Iface, void *Addr, void *Mask, void *Router);
  87
  88 // === CODE ===
  89 int main(int argc, char *argv[])
  90 {
  91         tInterface      *ifaces = NULL, *i;
  92
  93         // TODO: Scan /Devices and search for network adapters
  94         if( argc > 2 ) {
  95                 fprintf(stderr, "Usage: %s <interface>\n", argv[0]);
  96                 return -1;
  97         }
  98
  99         if( argc == 2 ) {
 100                 ifaces = malloc(sizeof(tInterface));
 101                 ifaces->Next = NULL;
 102                 ifaces->Adapter = argv[1];
 103         }
 104         else {
 105                 Scan_Dir( &ifaces, "/Devices/ip/adapters" );
 106         }
 107
 108         for( i = ifaces; i; i = i->Next )
 109         {
 110                 if( Start_Interface(i) < 0 ) {
 111                         return -1;
 112                 }
 113                 i->State = STATE_PREINIT;
 114
 115                 // Send request
 116                 Send_DHCPDISCOVER(i);
 117         }
 118
 119         while( ifaces )
 120         {
 121                  int    maxfd;
 122                 fd_set  fds;
 123                 tInterface      *p;
 124                 int64_t timeout = 1000;
 125
 126                 maxfd = 0;
 127                 FD_ZERO(&fds);
 128                 for( i = ifaces; i; i = i->Next )
 129                 {
 130                         FD_SET(i->SocketFD, &fds);
 131                         if(maxfd < i->SocketFD) maxfd = i->SocketFD;
 132                 }
 133
 134                 if( select(maxfd+1, &fds, NULL, NULL, &timeout) < 0 )
 135                 {
 136                         // TODO: Check error result
 137                         return -1;
 138                 }
 139
 140                 _SysDebug("select() returned");
 141
 142                 // Check for changes (with magic to allow inline deletion)
 143                 for( p = (void*)&ifaces, i = ifaces; i; p=i,i = i->Next )
 144                 {
 145                         if( FD_ISSET(i->SocketFD, &fds) )
 146                         {
 147                                 if( Handle_Packet( i ) )
 148                                 {
 149                                         _SysClose(i->SocketFD);
 150                                         _SysClose(i->IfaceFD);
 151                                         p->Next = i->Next;
 152                                         free(i);
 153                                         i = p;
 154                                 }
 155                         }
 156
 157                         if( _SysTimestamp() > i->Timeout )
 158                         {
 159                                 Handle_Timeout(i);
 160                         }
 161                 }
 162         }
 163         return 0;
 164 }
 165
 166 void Scan_Dir(tInterface **IfaceList, const char *Directory)
 167 {
 168         int dp = _SysOpen(Directory, OPENFLAG_READ);
 169         char filename[FILENAME_MAX];
 170
 171         if( dp == -1 ) {
 172                 fprintf(stderr, "Unable to open directory '%s'\n", Directory);
 173                 return ;
 174         }
 175
 176         while( _SysReadDir(dp, filename) )
 177         {
 178                 if( filename[0] == '.' )        continue ;
 179                 if( strcmp(filename, "lo") == 0 )       continue ;
 180
 181                 tInterface *new = malloc(sizeof(tInterface) + strlen(filename)+1);
 182                 new->Adapter = (void*)(new + 1);
 183                 strcpy(new->Adapter, filename);
 184                 new->Next = *IfaceList;
 185                 *IfaceList = new;
 186         }
 187         _SysClose(dp);
 188 }
 189
 190 // RETURN: Client FD
 191 int Start_Interface(tInterface *Iface)
 192 {
 193          int    fd, tmp;
 194         char    path[] = "/Devices/ip/XXXXX/udpc";
 195         char    addr[4] = {0,0,0,0};
 196
 197         // TODO: Check that the adapter is not in use
 198
 199         // Request MAC address from network adapter
 200         {
 201                 char    path[] = "/Devices/ip/adapters/ethXXXX";
 202                 sprintf(path, "/Devices/ip/adapters/%s", Iface->Adapter);
 203                 fd = _SysOpen(path, 0);
 204                 if(fd == -1) {
 205                         _SysDebug("Unable to open adapter %s", path);
 206                         return -1;
 207                 }
 208                 _SysIOCtl(fd, 4, Iface->HWAddr);
 209                 // TODO: Check if ioctl() failed
 210                 _SysClose(fd);
 211         }
 212
 213         // Initialise an interface, with a dummy IP address (zero)
 214         fd = _SysOpen("/Devices/ip", 0);
 215         if( fd == -1 ) {
 216                 fprintf(stderr, "ERROR: Unable to open '/Devices/ip'\n");
 217                 return -1;
 218         }
 219         Iface->Num = _SysIOCtl(fd, 4, (void*)Iface->Adapter);   // Create interface
 220         if( Iface->Num == -1 ) {
 221                 fprintf(stderr, "ERROR: Unable to create new interface\n");
 222                 return -1;
 223         }
 224         _SysClose(fd);
 225
 226         // Open new interface
 227         snprintf(path, sizeof(path), "/Devices/ip/%i", Iface->Num);
 228         Iface->IfaceFD = fd = _SysOpen(path, 0);
 229         if( fd == -1 ) {
 230                 fprintf(stderr, "ERROR: Unable to open '%s'\n", path);
 231                 return -1;
 232         }
 233         tmp = 4; _SysIOCtl(fd, 4, &tmp);        // Set to IPv4
 234         _SysIOCtl(fd, 6, addr); // Set address to 0.0.0.0
 235         tmp = 0; _SysIOCtl(fd, 7, &tmp);        // Set subnet mask to 0
 236
 237         // Open UDP Client
 238         snprintf(path, sizeof(path), "/Devices/ip/%i/udp", Iface->Num);
 239         Iface->SocketFD = fd = _SysOpen(path, O_RDWR);
 240         if( fd == -1 ) {
 241                 fprintf(stderr, "ERROR: Unable to open '%s'\n", path);
 242                 return -1;
 243         }
 244         tmp = 68; _SysIOCtl(fd, 4, &tmp);       // Local port
 245         tmp = 67; _SysIOCtl(fd, 5, &tmp);       // Remote port
 246         tmp = 0;        _SysIOCtl(fd, 7, &tmp); // Remote addr mask bits - we don't care where the reply comes from
 247         addr[0] = addr[1] = addr[2] = addr[3] = 255;    // 255.255.255.255
 248         _SysIOCtl(fd, 8, addr); // Remote address
 249
 250         return 0;
 251 }
 252
 253 void Send_DHCPRELEASE(tInterface *Iface)
 254 {
 255 }
 256
 257 void Send_DHCPDISCOVER(tInterface *Iface)
 258 {
 259         uint32_t        transaction_id;
 260         struct sDHCP_Message    *msg;
 261         char    data[8 + sizeof(struct sDHCP_Message) + 3 + 1];
 262         msg = (void*)data + 8;
 263
 264         _SysDebug("DHCPDISCOVER to %s", Iface->Adapter);
 265
 266         transaction_id = rand();
 267         Iface->TransactionID = transaction_id;
 268
 269         msg->op    = htonb(1);  // BOOTREQUEST
 270         msg->htype = htonb(1);  // 10mb Ethernet
 271         msg->hlen  = htonb(6);  // 6 byte MAC
 272         msg->hops  = htonb(0);  // Hop count so far
 273         msg->xid   = htonl(transaction_id);     // Transaction ID
 274         msg->secs  = htons(0);  // secs - No time has elapsed
 275         msg->flags = htons(0x0000);     // flags - Broadcast is unset
 276         msg->ciaddr = htonl(0); // ciaddr - Zero, as we don't have one yet
 277         msg->yiaddr = htonl(0); // yiaddr - Zero?
 278         msg->siaddr = htonl(0); // siaddr - Zero? maybe -1
 279         msg->giaddr = htonl(0); // giaddr - Zero?
 280         memcpy(msg->chaddr, Iface->HWAddr, 6);
 281
 282         memset(msg->sname, 0, sizeof(msg->sname));      // Nuke the rest
 283         memset(msg->file, 0, sizeof(msg->file));        // Nuke the rest
 284         msg->dhcp_magic = htonl(DHCP_MAGIC);
 285
 286         int i = 0;
 287         msg->options[i++] =  53;        // DHCP Message Type
 288         msg->options[i++] =   1;
 289         msg->options[i++] =   1;        // - DHCPDISCOVER
 290         msg->options[i++] = 255;        // End of list
 291
 292
 293         data[0] = 67;   data[1] = 0;    // Port
 294         data[2] = 4;    data[3] = 0;    // AddrType
 295         data[4] = 255;  data[5] = 255;  data[6] = 255;  data[7] = 255;
 296
 297         _SysWrite(Iface->SocketFD, data, sizeof(data));
 298         Update_State(Iface, STATE_DISCOVER_SENT);
 299 }
 300
 301 void Send_DHCPREQUEST(tInterface *Iface, void *OfferPacket, int TypeOffset)
 302 {
 303         struct sDHCP_Message    *msg;
 304          int    i;
 305         msg = (void*) ((char*)OfferPacket) + 8;
 306
 307         // Reuses old data :)
 308         msg->op    = 1;
 309         msg->htype = 1;
 310         msg->hlen  = 6;
 311         msg->hops  = 0;
 312         msg->xid   = msg->xid;
 313         msg->secs  = htons(0);  // TODO: Maintain times
 314         msg->flags = htons(0);
 315         memcpy(msg->chaddr, Iface->HWAddr, 6);
 316         memset(msg->sname, 0, sizeof(msg->sname));      // Nuke the rest
 317         memset(msg->file, 0, sizeof(msg->file));        // Nuke the rest
 318
 319         i = 0;
 320         msg->options[i++] = 53; // Message type = DHCPREQUEST
 321         msg->options[i++] = 1;
 322         msg->options[i++] = 3;
 323         msg->options[i++] = 50; // Requested Address
 324         msg->options[i++] = 4;
 325         memcpy(msg->options + i, &msg->yiaddr, 4);      i += 4;
 326 //      msg->options[i++] = 54; // Server identifier
 327 //      msg->options[i++] = 4;
 328 //      memcpy(msg->options + i, (char*)OfferPacket + 4, 4);    i += 4;
 329         msg->options[i++] = 255;
 330
 331         // Clear last because yiaddr is needed in option setup
 332         msg->ciaddr = htonl(0);
 333         msg->yiaddr = htonl(0);
 334         msg->siaddr = htonl(0);
 335         msg->giaddr = htonl(0);
 336
 337         // HACK
 338         ((uint8_t*)OfferPacket)[4] = 255;
 339         ((uint8_t*)OfferPacket)[5] = 255;
 340         ((uint8_t*)OfferPacket)[6] = 255;
 341         ((uint8_t*)OfferPacket)[7] = 255;
 342
 343         _SysWrite(Iface->SocketFD, OfferPacket, 8 + sizeof(*msg) + i);
 344         Update_State(Iface, STATE_REQUEST_SENT);
 345 }
 346
 347 int Handle_Packet(tInterface *Iface)
 348 {
 349         char    data[8+576];
 350         struct sDHCP_Message    *msg = (void*)(data + 8);
 351          int    len, i;
 352
 353          int    dhcp_msg_type = 0, dhcp_msg_type_ofs;
 354         void    *router = NULL;
 355         void    *subnet_mask = NULL;
 356
 357         _SysDebug("Doing read on %i", Iface->SocketFD);
 358         len = _SysRead(Iface->SocketFD, data, sizeof(data));
 359         _SysDebug("len = %i", len);
 360
 361         _SysDebug("*msg = {");
 362         _SysDebug("  .op = %i", msg->op);
 363         _SysDebug("  .htype = %i", msg->htype);
 364         _SysDebug("  .ciaddr = 0x%x", ntohl(msg->ciaddr));
 365         _SysDebug("  .yiaddr = 0x%x", ntohl(msg->yiaddr));
 366         _SysDebug("}");
 367         if( msg->op != 2 ) {
 368                 // Not a response
 369                 _SysDebug("Not a response message");
 370                 return 0;
 371         }
 372
 373         if( htonl(msg->dhcp_magic) != DHCP_MAGIC ) {
 374                 _SysDebug("DHCP magic doesn't match (got 0x%x, expected 0x%x)",
 375                         htonl(msg->dhcp_magic), DHCP_MAGIC);
 376                 return 0;
 377         }
 378
 379
 380         // Check if the packet is related to our requests
 381         if( ntohl(msg->xid) != Iface->TransactionID ) {
 382                 _SysDebug("Transaction ID mis-match, ignoring (0x%x != 0x%x)",
 383                         ntohl(msg->xid), Iface->TransactionID);
 384                 return 0;
 385         }
 386         if( memcmp(msg->chaddr, Iface->HWAddr, 6) != 0 ) {
 387                 _SysDebug("Hardware address mis-match, ignoring");
 388                 return 0;
 389         }
 390
 391         // Parse options
 392         i = 0;
 393         while( i < len - sizeof(*msg) - 8 && msg->options[i] != 255 )
 394         {
 395                 if( msg->options[i] == 0 ) {
 396                         i ++;
 397                         continue ;
 398                 }
 399                 _SysDebug("Option %i, %i bytes long", msg->options[i], msg->options[i+1]);
 400                 switch(msg->options[i])
 401                 {
 402                 case 1:
 403                         subnet_mask = &msg->options[i+2];
 404                         break;
 405                 case 3:
 406                         router = &msg->options[i+2];
 407                         break;
 408                 case 53:
 409                         dhcp_msg_type_ofs = i;
 410                         dhcp_msg_type = msg->options[i+2];
 411                         break;
 412                 }
 413                 i += msg->options[i+1]+2;
 414         }
 415
 416         _SysDebug("dhcp_msg_type = %i", dhcp_msg_type);
 417
 418         switch( dhcp_msg_type )
 419         {
 420         case 1: // DHCPDISCOVER - wut?
 421                 break;
 422         case 2: // DHCPOFFER
 423                 // Send out request for this address
 424                 if( Iface->State != STATE_DISCOVER_SENT ) {
 425                         _SysDebug("Ignoring DHCPOFFER when not in STATE_DISCOVER_SENT");
 426                         return 0;
 427                 }
 428                 Send_DHCPREQUEST(Iface, data, dhcp_msg_type_ofs);
 429                 break;
 430         case 3: // DHCPREQUEST - wut?
 431                 break;
 432         case 4: // DHCPDECLINE - ?
 433                 break;
 434         case 5: // DHCPACK
 435                 SetAddress(Iface, &msg->yiaddr, subnet_mask, router);
 436                 // Return 1 to remove from list
 437                 return 1;
 438         }
 439         return 0;
 440 }
 441
 442 void Handle_Timeout(tInterface *Iface)
 443 {
 444         switch(Iface->State)
 445         {
 446         case STATE_DISCOVER_SENT:
 447                 Send_DHCPDISCOVER(Iface);
 448                 break;
 449         default:
 450                 _SysDebug("Timeout with state = %i", Iface->State);
 451                 break;
 452         }
 453 }
 454
 455 void Update_State(tInterface *Iface, int newState)
 456 {
 457         if( Iface->State != newState )
 458         {
 459                 Iface->Timeout = _SysTimestamp() + 500;
 460                 Iface->State = newState;
 461         }
 462         else
 463         {
 464                 // TODO: Exponential backoff
 465                 Iface->Timeout = _SysTimestamp() + 3000;
 466                 _SysDebug("State %i repeated, timeout is 3000ms now", newState);
 467         }
 468 }
 469
 470 void SetAddress(tInterface *Iface, void *Addr, void *Mask, void *Router)
 471 {
 472          int    mask_bits = 0;
 473
 474         // Translate the mask
 475         if( Mask )
 476         {
 477                 uint8_t *mask = Mask;
 478                  int    i;
 479                 _SysDebug("Mask %i.%i.%i.%i", mask[0], mask[1], mask[2], mask[3]);
 480                 for( i = 0; i < 4 && mask[i] == 0xFF; i ++ ) ;
 481                 mask_bits = i*8;
 482                 if( i == 4 )
 483                 {
 484                         // Wut? /32?
 485                 }
 486                 else
 487                 {
 488                         switch(mask[i])
 489                         {
 490                         case 0x00:      mask_bits += 0; break;
 491                         case 0x80:      mask_bits += 1; break;
 492                         case 0xC0:      mask_bits += 2; break;
 493                         case 0xE0:      mask_bits += 3; break;
 494                         case 0xF0:      mask_bits += 4; break;
 495                         case 0xF8:      mask_bits += 5; break;
 496                         case 0xFC:      mask_bits += 6; break;
 497                         case 0xFE:      mask_bits += 7; break;
 498                         default:
 499                                 // Bad mask!
 500                                 break;
 501                         }
 502                 }
 503         }
 504
 505         {
 506                 uint8_t *addr = Addr;
 507                 _SysDebug("Addr %i.%i.%i.%i/%i", addr[0], addr[1], addr[2], addr[3], mask_bits);
 508
 509                 printf("Assigned %i.%i.%i.%i/%i to IF#%i (%s)\n",
 510                         addr[0], addr[1], addr[2], addr[3], mask_bits,
 511                         Iface->Num, Iface->Adapter
 512                         );
 513         }
 514
 515         _SysIOCtl(Iface->IfaceFD, 6, Addr);
 516         _SysIOCtl(Iface->IfaceFD, 7, &mask_bits);
 517
 518         if( Router );
 519         {
 520                 uint8_t *addr = Router;
 521                 _SysDebug("Router %i.%i.%i.%i", addr[0], addr[1], addr[2], addr[3]);
 522
 523                 // Set default route
 524                  int    fd;
 525                 fd = _SysOpen("/Devices/ip/routes/4:00000000:0:0", OPENFLAG_CREATE);
 526                 if(fd == -1) {
 527                         fprintf(stderr, "ERROR: Unable to open default route\n");
 528                 }
 529                 else {
 530                         char ifname[snprintf(NULL,0,"%i",Iface->Num)+1];
 531                         sprintf(ifname, "%i", Iface->Num);
 532                         _SysIOCtl(fd, _SysIOCtl(fd, 3, "set_nexthop"), Router);
 533                         _SysIOCtl(fd, _SysIOCtl(fd, 3, "set_interface"), ifname);
 534                         _SysClose(fd);
 535                 }
 536         }
 537 }
 538