Usermode/Applications/dhcpclient_src/main.c

   1 /*
   2  *
   3  * http://www.ietf.org/rfc/rfc2131.txt
   4  */
   5 #include <stdint.h>
   6 #include <stdio.h>
   7 #include <string.h>
   8 #include <stdlib.h>
   9 #include <net.h>
  10 #include <acess/sys.h>
  11
  12 #define FILENAME_MAX    255
  13 // --- Translation functions ---
  14 static inline uint32_t htonl(uint32_t v)
  15 {
  16         return    (((v >> 24) & 0xFF) <<  0)
  17                 | (((v >> 16) & 0xFF) <<  8)
  18                 | (((v >>  8) & 0xFF) << 16)
  19                 | (((v >>  0) & 0xFF) << 24);
  20 }
  21 static inline uint16_t htons(uint16_t v)
  22 {
  23         return    (((v >> 8) & 0xFF) <<  0)
  24                 | (((v >> 0) & 0xFF) <<  8);
  25 }
  26 #define htonb(v)        v
  27 #define ntohl(v)        htonl(v)
  28 #define ntohs(v)        htons(v)
  29
  30 // === CONSTANTS ===
  31 enum eStates
  32 {
  33         STATE_PREINIT,
  34         STATE_DISCOVER_SENT,
  35         STATE_REQUEST_SENT,
  36         STATE_COMPLETE,
  37 };
  38
  39 // === STRUCTURES ===
  40 #define DHCP_MAGIC      0x63825363
  41 struct sDHCP_Message
  42 {
  43         uint8_t op;
  44         uint8_t htype;  // 1 = Ethernet
  45         uint8_t hlen;   // 6 bytes for MAC
  46         uint8_t hops;   // Hop counting
  47         uint32_t        xid;
  48         uint16_t        secs;
  49         uint16_t        flags;
  50         uint32_t        ciaddr;
  51         uint32_t        yiaddr;
  52         uint32_t        siaddr;
  53         uint32_t        giaddr;
  54         uint8_t chaddr[16];
  55         uint8_t sname[64];
  56         uint8_t file[128];
  57         uint32_t        dhcp_magic;     // 0x63 0x82 0x53 0x63
  58         uint8_t options[];
  59 };
  60
  61 typedef struct sInterface
  62 {
  63         struct sInterface       *Next;
  64         char    *Adapter;
  65          int    State;
  66          int    Num;
  67          int    SocketFD;
  68          int    IfaceFD;
  69
  70         uint32_t        TransactionID;
  71         char    HWAddr[6];
  72
  73         int64_t Timeout;
  74          int    nTimeouts;
  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  int    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                                         goto _remove;
 149                         }
 150
 151                         if( _SysTimestamp() > i->Timeout )
 152                         {
 153                                 if( Handle_Timeout(i) )
 154                                 {
 155                                         fprintf(stderr, "%s timed out\n", i->Adapter);
 156                                         goto _remove;
 157                                 }
 158                         }
 159                         continue ;
 160                 _remove:
 161                         _SysClose(i->SocketFD);
 162                         _SysClose(i->IfaceFD);
 163                         p->Next = i->Next;
 164                         free(i);
 165                         i = p;
 166                 }
 167         }
 168         return 0;
 169 }
 170
 171 void Scan_Dir(tInterface **IfaceList, const char *Directory)
 172 {
 173         int dp = _SysOpen(Directory, OPENFLAG_READ);
 174         char filename[FILENAME_MAX];
 175
 176         if( dp == -1 ) {
 177                 fprintf(stderr, "Unable to open directory '%s'\n", Directory);
 178                 return ;
 179         }
 180
 181         while( _SysReadDir(dp, filename) )
 182         {
 183                 if( filename[0] == '.' )        continue ;
 184                 if( strcmp(filename, "lo") == 0 )       continue ;
 185
 186                 tInterface *new = malloc(sizeof(tInterface) + strlen(filename)+1);
 187                 new->Adapter = (void*)(new + 1);
 188                 strcpy(new->Adapter, filename);
 189                 new->Next = *IfaceList;
 190                 *IfaceList = new;
 191         }
 192         _SysClose(dp);
 193 }
 194
 195 // RETURN: Client FD
 196 int Start_Interface(tInterface *Iface)
 197 {
 198          int    fd, tmp;
 199         char    path[] = "/Devices/ip/XXXXX/udpc";
 200         char    addr[4] = {0,0,0,0};
 201
 202         // TODO: Check that the adapter is not in use
 203
 204         // Request MAC address from network adapter
 205         {
 206                 char    path[] = "/Devices/ip/adapters/ethXXXX";
 207                 sprintf(path, "/Devices/ip/adapters/%s", Iface->Adapter);
 208                 fd = _SysOpen(path, 0);
 209                 if(fd == -1) {
 210                         _SysDebug("Unable to open adapter %s", path);
 211                         return -1;
 212                 }
 213                 _SysIOCtl(fd, 4, Iface->HWAddr);
 214                 // TODO: Check if ioctl() failed
 215                 _SysClose(fd);
 216         }
 217
 218         // Initialise an interface, with a dummy IP address (zero)
 219         fd = _SysOpen("/Devices/ip", 0);
 220         if( fd == -1 ) {
 221                 fprintf(stderr, "ERROR: Unable to open '/Devices/ip'\n");
 222                 return -1;
 223         }
 224         Iface->Num = _SysIOCtl(fd, 4, (void*)Iface->Adapter);   // Create interface
 225         if( Iface->Num == -1 ) {
 226                 fprintf(stderr, "ERROR: Unable to create new interface\n");
 227                 return -1;
 228         }
 229         _SysClose(fd);
 230
 231         // Open new interface
 232         snprintf(path, sizeof(path), "/Devices/ip/%i", Iface->Num);
 233         Iface->IfaceFD = fd = _SysOpen(path, 0);
 234         if( fd == -1 ) {
 235                 fprintf(stderr, "ERROR: Unable to open '%s'\n", path);
 236                 return -1;
 237         }
 238         tmp = 4; _SysIOCtl(fd, 4, &tmp);        // Set to IPv4
 239         _SysIOCtl(fd, 6, addr); // Set address to 0.0.0.0
 240         tmp = 0; _SysIOCtl(fd, 7, &tmp);        // Set subnet mask to 0
 241
 242         // Open UDP Client
 243         snprintf(path, sizeof(path), "/Devices/ip/%i/udp", Iface->Num);
 244         Iface->SocketFD = fd = _SysOpen(path, OPENFLAG_READ|OPENFLAG_WRITE);
 245         if( fd == -1 ) {
 246                 fprintf(stderr, "ERROR: Unable to open '%s'\n", path);
 247                 return -1;
 248         }
 249         tmp = 68; _SysIOCtl(fd, 4, &tmp);       // Local port
 250         tmp = 67; _SysIOCtl(fd, 5, &tmp);       // Remote port
 251         tmp = 0;        _SysIOCtl(fd, 7, &tmp); // Remote addr mask bits - we don't care where the reply comes from
 252         addr[0] = addr[1] = addr[2] = addr[3] = 255;    // 255.255.255.255
 253         _SysIOCtl(fd, 8, addr); // Remote address
 254
 255         return 0;
 256 }
 257
 258 void Send_DHCPRELEASE(tInterface *Iface)
 259 {
 260 }
 261
 262 void Send_DHCPDISCOVER(tInterface *Iface)
 263 {
 264         uint32_t        transaction_id;
 265         struct sDHCP_Message    *msg;
 266         char    data[8 + sizeof(struct sDHCP_Message) + 3 + 1];
 267         msg = (void*)data + 8;
 268
 269         _SysDebug("DHCPDISCOVER to %s", Iface->Adapter);
 270
 271         transaction_id = rand();
 272         Iface->TransactionID = transaction_id;
 273
 274         msg->op    = htonb(1);  // BOOTREQUEST
 275         msg->htype = htonb(1);  // 10mb Ethernet
 276         msg->hlen  = htonb(6);  // 6 byte MAC
 277         msg->hops  = htonb(0);  // Hop count so far
 278         msg->xid   = htonl(transaction_id);     // Transaction ID
 279         msg->secs  = htons(0);  // secs - No time has elapsed
 280         msg->flags = htons(0x0000);     // flags - Broadcast is unset
 281         msg->ciaddr = htonl(0); // ciaddr - Zero, as we don't have one yet
 282         msg->yiaddr = htonl(0); // yiaddr - Zero?
 283         msg->siaddr = htonl(0); // siaddr - Zero? maybe -1
 284         msg->giaddr = htonl(0); // giaddr - Zero?
 285         memcpy(msg->chaddr, Iface->HWAddr, 6);
 286
 287         memset(msg->sname, 0, sizeof(msg->sname));      // Nuke the rest
 288         memset(msg->file, 0, sizeof(msg->file));        // Nuke the rest
 289         msg->dhcp_magic = htonl(DHCP_MAGIC);
 290
 291         int i = 0;
 292         msg->options[i++] =  53;        // DHCP Message Type
 293         msg->options[i++] =   1;
 294         msg->options[i++] =   1;        // - DHCPDISCOVER
 295         msg->options[i++] = 255;        // End of list
 296
 297
 298         data[0] = 67;   data[1] = 0;    // Port
 299         data[2] = 4;    data[3] = 0;    // AddrType
 300         data[4] = 255;  data[5] = 255;  data[6] = 255;  data[7] = 255;
 301
 302         i = _SysWrite(Iface->SocketFD, data, sizeof(data));
 303         if( i != sizeof(data) ) {
 304                 _SysDebug("_SysWrite failed (%i != %i)", i, sizeof(data));
 305         }
 306         Update_State(Iface, STATE_DISCOVER_SENT);
 307 }
 308
 309 void Send_DHCPREQUEST(tInterface *Iface, void *OfferPacket, int TypeOffset)
 310 {
 311         struct sDHCP_Message    *msg;
 312          int    i;
 313         msg = (void*) ((char*)OfferPacket) + 8;
 314
 315         // Reuses old data :)
 316         msg->op    = 1;
 317         msg->htype = 1;
 318         msg->hlen  = 6;
 319         msg->hops  = 0;
 320         msg->xid   = msg->xid;
 321         msg->secs  = htons(0);  // TODO: Maintain times
 322         msg->flags = htons(0);
 323         memcpy(msg->chaddr, Iface->HWAddr, 6);
 324         memset(msg->sname, 0, sizeof(msg->sname));      // Nuke the rest
 325         memset(msg->file, 0, sizeof(msg->file));        // Nuke the rest
 326
 327         i = 0;
 328         msg->options[i++] = 53; // Message type = DHCPREQUEST
 329         msg->options[i++] = 1;
 330         msg->options[i++] = 3;
 331         msg->options[i++] = 50; // Requested Address
 332         msg->options[i++] = 4;
 333         memcpy(msg->options + i, &msg->yiaddr, 4);      i += 4;
 334 //      msg->options[i++] = 54; // Server identifier
 335 //      msg->options[i++] = 4;
 336 //      memcpy(msg->options + i, (char*)OfferPacket + 4, 4);    i += 4;
 337         msg->options[i++] = 255;
 338
 339         // Clear last because yiaddr is needed in option setup
 340         msg->ciaddr = htonl(0);
 341         msg->yiaddr = htonl(0);
 342         msg->siaddr = htonl(0);
 343         msg->giaddr = htonl(0);
 344
 345         // HACK
 346         ((uint8_t*)OfferPacket)[4] = 255;
 347         ((uint8_t*)OfferPacket)[5] = 255;
 348         ((uint8_t*)OfferPacket)[6] = 255;
 349         ((uint8_t*)OfferPacket)[7] = 255;
 350
 351         _SysWrite(Iface->SocketFD, OfferPacket, 8 + sizeof(*msg) + i);
 352         Update_State(Iface, STATE_REQUEST_SENT);
 353 }
 354
 355 int Handle_Packet(tInterface *Iface)
 356 {
 357         char    data[8+576];
 358         struct sDHCP_Message    *msg = (void*)(data + 8);
 359          int    len, i;
 360
 361          int    dhcp_msg_type = 0, dhcp_msg_type_ofs;
 362         void    *router = NULL;
 363         void    *subnet_mask = NULL;
 364
 365         _SysDebug("Doing read on %i", Iface->SocketFD);
 366         len = _SysRead(Iface->SocketFD, data, sizeof(data));
 367         _SysDebug("len = %i", len);
 368
 369         _SysDebug("*msg = {");
 370         _SysDebug("  .op = %i", msg->op);
 371         _SysDebug("  .htype = %i", msg->htype);
 372         _SysDebug("  .ciaddr = 0x%x", ntohl(msg->ciaddr));
 373         _SysDebug("  .yiaddr = 0x%x", ntohl(msg->yiaddr));
 374         _SysDebug("}");
 375         if( msg->op != 2 ) {
 376                 // Not a response
 377                 _SysDebug("Not a response message");
 378                 return 0;
 379         }
 380
 381         if( htonl(msg->dhcp_magic) != DHCP_MAGIC ) {
 382                 _SysDebug("DHCP magic doesn't match (got 0x%x, expected 0x%x)",
 383                         htonl(msg->dhcp_magic), DHCP_MAGIC);
 384                 return 0;
 385         }
 386
 387
 388         // Check if the packet is related to our requests
 389         if( ntohl(msg->xid) != Iface->TransactionID ) {
 390                 _SysDebug("Transaction ID mis-match, ignoring (0x%x != 0x%x)",
 391                         ntohl(msg->xid), Iface->TransactionID);
 392                 return 0;
 393         }
 394         if( memcmp(msg->chaddr, Iface->HWAddr, 6) != 0 ) {
 395                 _SysDebug("Hardware address mis-match, ignoring");
 396                 return 0;
 397         }
 398
 399         // Parse options
 400         i = 0;
 401         while( i < len - sizeof(*msg) - 8 && msg->options[i] != 255 )
 402         {
 403                 if( msg->options[i] == 0 ) {
 404                         i ++;
 405                         continue ;
 406                 }
 407                 _SysDebug("Option %i, %i bytes long", msg->options[i], msg->options[i+1]);
 408                 switch(msg->options[i])
 409                 {
 410                 case 1:
 411                         subnet_mask = &msg->options[i+2];
 412                         break;
 413                 case 3:
 414                         router = &msg->options[i+2];
 415                         break;
 416                 case 53:
 417                         dhcp_msg_type_ofs = i;
 418                         dhcp_msg_type = msg->options[i+2];
 419                         break;
 420                 }
 421                 i += msg->options[i+1]+2;
 422         }
 423
 424         _SysDebug("dhcp_msg_type = %i", dhcp_msg_type);
 425
 426         switch( dhcp_msg_type )
 427         {
 428         case 1: // DHCPDISCOVER - wut?
 429                 break;
 430         case 2: // DHCPOFFER
 431                 // Send out request for this address
 432                 if( Iface->State != STATE_DISCOVER_SENT ) {
 433                         _SysDebug("Ignoring DHCPOFFER when not in STATE_DISCOVER_SENT");
 434                         return 0;
 435                 }
 436                 Send_DHCPREQUEST(Iface, data, dhcp_msg_type_ofs);
 437                 break;
 438         case 3: // DHCPREQUEST - wut?
 439                 break;
 440         case 4: // DHCPDECLINE - ?
 441                 break;
 442         case 5: // DHCPACK
 443                 SetAddress(Iface, &msg->yiaddr, subnet_mask, router);
 444                 // Return 1 to remove from list
 445                 return 1;
 446         }
 447         return 0;
 448 }
 449
 450 int Handle_Timeout(tInterface *Iface)
 451 {
 452         if( Iface->nTimeouts == 3 )
 453                 return 1;
 454         switch(Iface->State)
 455         {
 456         case STATE_DISCOVER_SENT:
 457                 Send_DHCPDISCOVER(Iface);
 458                 break;
 459         default:
 460                 _SysDebug("Timeout with state = %i", Iface->State);
 461                 break;
 462         }
 463         return 0;
 464 }
 465
 466 void Update_State(tInterface *Iface, int newState)
 467 {
 468         if( Iface->State != newState )
 469         {
 470                 Iface->Timeout = _SysTimestamp() + 500;
 471                 Iface->State = newState;
 472                 Iface->nTimeouts = 0;
 473         }
 474         else
 475         {
 476                 // TODO: Exponential backoff
 477                 Iface->Timeout = _SysTimestamp() + 3000;
 478                 Iface->nTimeouts ++;
 479                 _SysDebug("State %i repeated, timeout is 3000ms now", newState);
 480         }
 481 }
 482
 483 void SetAddress(tInterface *Iface, void *Addr, void *Mask, void *Router)
 484 {
 485          int    mask_bits = 0;
 486
 487         // Translate the mask
 488         if( Mask )
 489         {
 490                 uint8_t *mask = Mask;
 491                  int    i;
 492                 _SysDebug("Mask %i.%i.%i.%i", mask[0], mask[1], mask[2], mask[3]);
 493                 for( i = 0; i < 4 && mask[i] == 0xFF; i ++ ) ;
 494                 mask_bits = i*8;
 495                 if( i == 4 )
 496                 {
 497                         // Wut? /32?
 498                 }
 499                 else
 500                 {
 501                         switch(mask[i])
 502                         {
 503                         case 0x00:      mask_bits += 0; break;
 504                         case 0x80:      mask_bits += 1; break;
 505                         case 0xC0:      mask_bits += 2; break;
 506                         case 0xE0:      mask_bits += 3; break;
 507                         case 0xF0:      mask_bits += 4; break;
 508                         case 0xF8:      mask_bits += 5; break;
 509                         case 0xFC:      mask_bits += 6; break;
 510                         case 0xFE:      mask_bits += 7; break;
 511                         default:
 512                                 // Bad mask!
 513                                 break;
 514                         }
 515                 }
 516         }
 517
 518         {
 519                 uint8_t *addr = Addr;
 520                 _SysDebug("Addr %i.%i.%i.%i/%i", addr[0], addr[1], addr[2], addr[3], mask_bits);
 521
 522                 printf("Assigned %i.%i.%i.%i/%i to IF#%i (%s)\n",
 523                         addr[0], addr[1], addr[2], addr[3], mask_bits,
 524                         Iface->Num, Iface->Adapter
 525                         );
 526         }
 527
 528         _SysIOCtl(Iface->IfaceFD, 6, Addr);
 529         _SysIOCtl(Iface->IfaceFD, 7, &mask_bits);
 530
 531         if( Router )
 532         {
 533                 uint8_t *addr = Router;
 534                 _SysDebug("Router %i.%i.%i.%i", addr[0], addr[1], addr[2], addr[3]);
 535
 536                 // Set default route
 537                  int    fd;
 538                 fd = _SysOpen("/Devices/ip/routes/4:00000000:0:0", OPENFLAG_CREATE);
 539                 if(fd == -1) {
 540                         fprintf(stderr, "ERROR: Unable to open default route\n");
 541                 }
 542                 else {
 543                         char ifname[snprintf(NULL,0,"%i",Iface->Num)+1];
 544                         sprintf(ifname, "%i", Iface->Num);
 545                         _SysIOCtl(fd, _SysIOCtl(fd, 3, "set_nexthop"), Router);
 546                         _SysIOCtl(fd, _SysIOCtl(fd, 3, "set_interface"), ifname);
 547                         _SysClose(fd);
 548                 }
 549         }
 550 }
 551