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 #include <errno.h>
  12
  13 enum {
  14         UDP_IOCTL_GETSETLPORT = 4,
  15         UDP_IOCTL_GETSETRPORT,
  16         UDP_IOCTL_GETSETRMASK,
  17         UDP_IOCTL_SETRADDR,
  18 };
  19
  20 #define FILENAME_MAX    255
  21 // --- Translation functions ---
  22 static inline uint32_t htonl(uint32_t v)
  23 {
  24         return    (((v >> 24) & 0xFF) <<  0)
  25                 | (((v >> 16) & 0xFF) <<  8)
  26                 | (((v >>  8) & 0xFF) << 16)
  27                 | (((v >>  0) & 0xFF) << 24);
  28 }
  29 static inline uint16_t htons(uint16_t v)
  30 {
  31         return    (((v >> 8) & 0xFF) <<  0)
  32                 | (((v >> 0) & 0xFF) <<  8);
  33 }
  34 #define htonb(v)        v
  35 #define ntohl(v)        htonl(v)
  36 #define ntohs(v)        htons(v)
  37
  38 // === CONSTANTS ===
  39 enum eStates
  40 {
  41         STATE_PREINIT,
  42         STATE_DISCOVER_SENT,
  43         STATE_REQUEST_SENT,
  44         STATE_COMPLETE,
  45 };
  46
  47 // === STRUCTURES ===
  48 #define DHCP_MAGIC      0x63825363
  49 struct sDHCP_Message
  50 {
  51         uint8_t op;
  52         uint8_t htype;  // 1 = Ethernet
  53         uint8_t hlen;   // 6 bytes for MAC
  54         uint8_t hops;   // Hop counting
  55         uint32_t        xid;
  56         uint16_t        secs;
  57         uint16_t        flags;
  58         uint32_t        ciaddr;
  59         uint32_t        yiaddr;
  60         uint32_t        siaddr;
  61         uint32_t        giaddr;
  62         uint8_t chaddr[16];
  63         uint8_t sname[64];
  64         uint8_t file[128];
  65         uint32_t        dhcp_magic;     // 0x63 0x82 0x53 0x63
  66         uint8_t options[];
  67 };
  68
  69 typedef struct sInterface
  70 {
  71         struct sInterface       *Next;
  72         char    *Adapter;
  73          int    State;
  74          int    Num;
  75          int    SocketFD;
  76          int    IfaceFD;
  77
  78         uint32_t        TransactionID;
  79         char    HWAddr[6];
  80
  81         int64_t StartTime;
  82         int64_t Timeout;
  83          int    nTimeouts;
  84 } tInterface;
  85
  86 // === PROTOTYPES ===
  87 int     main(int argc, char *argv[]);
  88 void    Scan_Dir(tInterface **IfaceList, const char *Directory);
  89 int     Start_Interface(tInterface *Iface);
  90 void    Send_DHCPDISCOVER(tInterface *Iface);
  91 void    Send_DHCPREQUEST(tInterface *Iface, void *OfferBuffer, int TypeOffset);
  92  int    Handle_Packet(tInterface *Iface);
  93  int    Handle_Timeout(tInterface *Iface);
  94 void    Update_State(tInterface *Iface, int newState);
  95 void    SetAddress(tInterface *Iface, void *Addr, void *Mask, void *Router);
  96
  97 // === CODE ===
  98 int main(int argc, char *argv[])
  99 {
 100         tInterface      *ifaces = NULL;
 101
 102         if( argc > 2 ) {
 103                 fprintf(stderr, "Usage: %s <interface>\n", argv[0]);
 104                 return -1;
 105         }
 106
 107         if( argc == 2 ) {
 108                 ifaces = malloc(sizeof(tInterface));
 109                 ifaces->Next = NULL;
 110                 ifaces->Adapter = argv[1];
 111         }
 112         else {
 113                 Scan_Dir( &ifaces, "/Devices/ip/adapters" );
 114         }
 115
 116         for( tInterface *i = ifaces; i; i = i->Next )
 117         {
 118                 if( Start_Interface(i) < 0 ) {
 119                         return -1;
 120                 }
 121                 i->State = STATE_PREINIT;
 122                 i->StartTime = _SysTimestamp();
 123
 124                 // Send request
 125                 Send_DHCPDISCOVER(i);
 126         }
 127
 128         while( ifaces )
 129         {
 130                  int    maxfd;
 131                 fd_set  fds;
 132                 int64_t timeout = 1000;
 133
 134                 maxfd = 0;
 135                 FD_ZERO(&fds);
 136                 for( tInterface *i = ifaces; i; i = i->Next )
 137                 {
 138                         FD_SET(i->SocketFD, &fds);
 139                         if(maxfd < i->SocketFD) maxfd = i->SocketFD;
 140                 }
 141
 142                 if( _SysSelect(maxfd+1, &fds, NULL, NULL, &timeout, 0) < 0 )
 143                 {
 144                         perror("_SysSelect returned error");
 145                         return -1;
 146                 }
 147
 148                 _SysDebug("select() returned");
 149
 150                 // Check for changes (with magic to allow inline deletion)
 151                 for( tInterface *p = (void*)&ifaces, *i = ifaces; i; p=i,i = i->Next )
 152                 {
 153                         if( FD_ISSET(i->SocketFD, &fds) )
 154                         {
 155                                 if( Handle_Packet( i ) )
 156                                         goto _remove;
 157                         }
 158
 159                         if( _SysTimestamp() > i->Timeout )
 160                         {
 161                                 if( Handle_Timeout(i) )
 162                                 {
 163                                         fprintf(stderr, "DHCP on %s timed out\n", i->Adapter);
 164                                         goto _remove;
 165                                 }
 166                         }
 167                         continue ;
 168                 _remove:
 169                         _SysClose(i->SocketFD);
 170                         _SysClose(i->IfaceFD);
 171                         p->Next = i->Next;
 172                         free(i);
 173                         i = p;
 174                 }
 175         }
 176         return 0;
 177 }
 178
 179 void Scan_Dir(tInterface **IfaceList, const char *Directory)
 180 {
 181         int dp = _SysOpen(Directory, OPENFLAG_READ);
 182         char filename[FILENAME_MAX];
 183
 184         if( dp == -1 ) {
 185                 fprintf(stderr, "Unable to open directory '%s'\n", Directory);
 186                 return ;
 187         }
 188
 189         while( _SysReadDir(dp, filename) )
 190         {
 191                 if( filename[0] == '.' )        continue ;
 192                 if( strcmp(filename, "lo") == 0 )       continue ;
 193
 194                 tInterface *new = malloc(sizeof(tInterface) + strlen(filename)+1);
 195                 new->Adapter = (void*)(new + 1);
 196                 strcpy(new->Adapter, filename);
 197                 new->Next = *IfaceList;
 198                 *IfaceList = new;
 199         }
 200         _SysClose(dp);
 201 }
 202
 203 // RETURN: Client FD
 204 int Start_Interface(tInterface *Iface)
 205 {
 206          int    fd, tmp;
 207         char    path[] = "/Devices/ip/XXXXX/udpc";
 208         char    addr[4] = {0,0,0,0};
 209
 210         // TODO: Check that the adapter is not in use
 211
 212         // Request MAC address from network adapter
 213         {
 214                 char    path[] = "/Devices/ip/adapters/ethXXXX";
 215                 sprintf(path, "/Devices/ip/adapters/%s", Iface->Adapter);
 216                 fd = _SysOpen(path, 0);
 217                 if(fd == -1) {
 218                         perror("Opening adapter");
 219                         _SysDebug("Unable to open adapter %s", path);
 220                         return -1;
 221                 }
 222                 if( _SysIOCtl(fd, 4, Iface->HWAddr) ) {
 223                         perror("Getting MAC address");
 224                         return -1;
 225                 }
 226                 _SysClose(fd);
 227         }
 228
 229         // Initialise an interface, with a dummy IP address (zero)
 230         fd = _SysOpen("/Devices/ip", 0);
 231         if( fd == -1 ) {
 232                 fprintf(stderr, "ERROR: Unable to open '/Devices/ip'\n");
 233                 return -1;
 234         }
 235         struct {
 236                 const char *Device;
 237                 const char *Name;
 238                  int    Type;
 239         } ifinfo;
 240         ifinfo.Device = Iface->Adapter;
 241         ifinfo.Name = "";
 242         ifinfo.Type = 4;
 243         Iface->Num = _SysIOCtl(fd, 4, &ifinfo); // Create interface
 244         if( Iface->Num == -1 ) {
 245                 fprintf(stderr, "ERROR: Unable to create new interface\n");
 246                 return -1;
 247         }
 248         _SysClose(fd);
 249
 250         // Open new interface
 251         snprintf(path, sizeof(path), "/Devices/ip/%i", Iface->Num);
 252         Iface->IfaceFD = fd = _SysOpen(path, 0);
 253         if( fd == -1 ) {
 254                 fprintf(stderr, "ERROR: Unable to open '%s'\n", path);
 255                 return -1;
 256         }
 257         _SysIOCtl(fd, 6, addr); // Set address to 0.0.0.0
 258         tmp = 0; _SysIOCtl(fd, 7, &tmp);        // Set subnet mask to 0
 259
 260         // Open UDP Client
 261         snprintf(path, sizeof(path), "/Devices/ip/%i/udp", Iface->Num);
 262         Iface->SocketFD = fd = _SysOpen(path, OPENFLAG_READ|OPENFLAG_WRITE);
 263         if( fd == -1 ) {
 264                 fprintf(stderr, "ERROR: Unable to open '%s'\n", path);
 265                 return -1;
 266         }
 267         tmp = 68; _SysIOCtl(fd, UDP_IOCTL_GETSETLPORT, &tmp);   // Local port
 268         tmp = 67; _SysIOCtl(fd, UDP_IOCTL_GETSETRPORT, &tmp);   // Remote port
 269         tmp = 0;  _SysIOCtl(fd, UDP_IOCTL_GETSETRMASK, &tmp);   // Remote addr mask bits - don't care source
 270         addr[0] = addr[1] = addr[2] = addr[3] = 255;    // 255.255.255.255
 271         _SysIOCtl(fd, UDP_IOCTL_SETRADDR, addr);        // Remote address
 272
 273         return 0;
 274 }
 275
 276 void Send_DHCPRELEASE(tInterface *Iface)
 277 {
 278 }
 279
 280 void Send_DHCPDISCOVER(tInterface *Iface)
 281 {
 282         uint32_t        transaction_id;
 283         struct sDHCP_Message    *msg;
 284         char    data[8 + sizeof(struct sDHCP_Message) + 3 + 1];
 285         msg = (void*)data + 8;
 286
 287         _SysDebug("DHCPDISCOVER to %s", Iface->Adapter);
 288
 289         transaction_id = rand();
 290         Iface->TransactionID = transaction_id;
 291
 292         msg->op    = htonb(1);  // BOOTREQUEST
 293         msg->htype = htonb(1);  // 10mb Ethernet
 294         msg->hlen  = htonb(6);  // 6 byte MAC
 295         msg->hops  = htonb(0);  // Hop count so far
 296         msg->xid   = htonl(transaction_id);     // Transaction ID
 297         msg->secs  = htons(0);  // secs - No time has elapsed
 298         msg->flags = htons(0x0000);     // flags - Broadcast is unset
 299         msg->ciaddr = htonl(0); // ciaddr - Zero, as we don't have one yet
 300         msg->yiaddr = htonl(0); // yiaddr - Zero?
 301         msg->siaddr = htonl(0); // siaddr - Zero? maybe -1
 302         msg->giaddr = htonl(0); // giaddr - Zero?
 303         memcpy(msg->chaddr, Iface->HWAddr, 6);
 304         memset(msg->chaddr+6, 0, sizeof(msg->chaddr)-6);
 305
 306         memset(msg->sname, 0, sizeof(msg->sname));      // Nuke the rest
 307         memset(msg->file, 0, sizeof(msg->file));        // Nuke the rest
 308         msg->dhcp_magic = htonl(DHCP_MAGIC);
 309
 310         int i = 0;
 311         msg->options[i++] =  53;        // DHCP Message Type
 312         msg->options[i++] =   1;
 313         msg->options[i++] =   1;        // - DHCPDISCOVER
 314         msg->options[i  ] = 255;        // End of list
 315
 316
 317         // UDP Header
 318         data[0] = 67;   data[1] = 0;    // Port
 319         data[2] = 4;    data[3] = 0;    // AddrType
 320         data[4] = 255;  data[5] = 255;  data[6] = 255;  data[7] = 255;
 321
 322         i = _SysWrite(Iface->SocketFD, data, sizeof(data));
 323         if( i != sizeof(data) ) {
 324                 _SysDebug("_SysWrite failed (%i != %i): %s", i, sizeof(data),
 325                         strerror(errno));
 326         }
 327         Update_State(Iface, STATE_DISCOVER_SENT);
 328 }
 329
 330 void Send_DHCPREQUEST(tInterface *Iface, void *OfferPacket, int TypeOffset)
 331 {
 332         struct sDHCP_Message    *msg;
 333          int    i;
 334         msg = (void*) ((char*)OfferPacket) + 8;
 335
 336         if( msg->xid != Iface->TransactionID ) {
 337                 return ;
 338         }
 339
 340         // Reuses old data :)
 341         msg->op    = htonb(1);
 342         msg->htype = htonb(1);
 343         msg->hlen  = htonb(6);
 344         msg->hops  = htonb(0);
 345         msg->xid   = htonl(Iface->TransactionID);
 346         msg->secs  = htons( (_SysTimestamp()-Iface->StartTime+499)/1000 );      // TODO: Maintain times
 347         msg->flags = htons(0x0000);
 348         memcpy(msg->chaddr, Iface->HWAddr, 6);
 349         memset(msg->sname, 0, sizeof(msg->sname));      // Nuke the rest
 350         memset(msg->file, 0, sizeof(msg->file));        // Nuke the rest
 351
 352         i = 0;
 353         msg->options[i++] = 53; // Message type = DHCPREQUEST
 354         msg->options[i++] = 1;
 355         msg->options[i++] = 3;
 356         msg->options[i++] = 50; // Requested Address
 357         msg->options[i++] = 4;
 358         memcpy(msg->options + i, &msg->yiaddr, 4);      i += 4;
 359 //      msg->options[i++] = 54; // Server identifier
 360 //      msg->options[i++] = 4;
 361 //      memcpy(msg->options + i, (char*)OfferPacket + 4, 4);    i += 4;
 362         msg->options[i++] = 255;
 363
 364         // Clear last because yiaddr is needed in option setup
 365         msg->ciaddr = htonl(0);
 366         msg->yiaddr = htonl(0);
 367         msg->siaddr = htonl(0);
 368         msg->giaddr = htonl(0);
 369
 370         // HACK
 371         ((uint8_t*)OfferPacket)[4] = 255;
 372         ((uint8_t*)OfferPacket)[5] = 255;
 373         ((uint8_t*)OfferPacket)[6] = 255;
 374         ((uint8_t*)OfferPacket)[7] = 255;
 375
 376         _SysWrite(Iface->SocketFD, OfferPacket, 8 + sizeof(*msg) + i);
 377         Update_State(Iface, STATE_REQUEST_SENT);
 378 }
 379
 380 int Handle_Packet(tInterface *Iface)
 381 {
 382         char    data[8+576];
 383         struct sDHCP_Message    *msg = (void*)(data + 8);
 384          int    len, i;
 385
 386          int    dhcp_msg_type = 0, dhcp_msg_type_ofs;
 387         void    *router = NULL;
 388         void    *subnet_mask = NULL;
 389
 390         _SysDebug("Doing read on %s %i", Iface->Adapter, Iface->SocketFD);
 391         len = _SysRead(Iface->SocketFD, data, sizeof(data));
 392         _SysDebug("len = %i", len);
 393
 394         _SysDebug("*msg = {");
 395         _SysDebug("  .op = %i", msg->op);
 396         _SysDebug("  .htype = %i", msg->htype);
 397         _SysDebug("  .ciaddr = 0x%x", ntohl(msg->ciaddr));
 398         _SysDebug("  .yiaddr = 0x%x", ntohl(msg->yiaddr));
 399         _SysDebug("}");
 400         if( msg->op != 2 ) {
 401                 // Not a response
 402                 _SysDebug("Not a response message");
 403                 return 0;
 404         }
 405
 406         if( htonl(msg->dhcp_magic) != DHCP_MAGIC ) {
 407                 _SysDebug("DHCP magic doesn't match (got 0x%x, expected 0x%x)",
 408                         htonl(msg->dhcp_magic), DHCP_MAGIC);
 409                 return 0;
 410         }
 411
 412
 413         // Check if the packet is related to our requests
 414         if( ntohl(msg->xid) != Iface->TransactionID ) {
 415                 _SysDebug("Transaction ID mis-match, ignoring (0x%x != 0x%x)",
 416                         ntohl(msg->xid), Iface->TransactionID);
 417                 return 0;
 418         }
 419         if( memcmp(msg->chaddr, Iface->HWAddr, 6) != 0 ) {
 420                 _SysDebug("Hardware address mis-match, ignoring");
 421                 return 0;
 422         }
 423
 424         // Parse options
 425         i = 0;
 426         while( i < len - sizeof(*msg) - 8 && msg->options[i] != 255 )
 427         {
 428                 if( msg->options[i] == 0 ) {
 429                         i ++;
 430                         continue ;
 431                 }
 432                 _SysDebug("Option %i, %i bytes long", msg->options[i], msg->options[i+1]);
 433                 switch(msg->options[i])
 434                 {
 435                 case 1:
 436                         subnet_mask = &msg->options[i+2];
 437                         break;
 438                 case 3:
 439                         router = &msg->options[i+2];
 440                         break;
 441                 case 53:
 442                         dhcp_msg_type_ofs = i;
 443                         dhcp_msg_type = msg->options[i+2];
 444                         break;
 445                 }
 446                 i += msg->options[i+1]+2;
 447         }
 448
 449         _SysDebug("dhcp_msg_type = %i", dhcp_msg_type);
 450
 451         switch( dhcp_msg_type )
 452         {
 453         case 1: // DHCPDISCOVER - wut?
 454                 break;
 455         case 2: // DHCPOFFER
 456                 // Send out request for this address
 457                 if( Iface->State != STATE_DISCOVER_SENT ) {
 458                         _SysDebug("Ignoring DHCPOFFER when not in STATE_DISCOVER_SENT");
 459                         return 0;
 460                 }
 461                 Send_DHCPREQUEST(Iface, data, dhcp_msg_type_ofs);
 462                 break;
 463         case 3: // DHCPREQUEST - wut?
 464                 break;
 465         case 4: // DHCPDECLINE - ?
 466                 break;
 467         case 5: // DHCPACK
 468                 SetAddress(Iface, &msg->yiaddr, subnet_mask, router);
 469                 // Return 1 to remove from list
 470                 return 1;
 471         }
 472         return 0;
 473 }
 474
 475 int Handle_Timeout(tInterface *Iface)
 476 {
 477         if( Iface->nTimeouts == 3 )
 478                 return 1;
 479         switch(Iface->State)
 480         {
 481         case STATE_DISCOVER_SENT:
 482                 fprintf(stderr, "DHCPDISCOVER timeout on %s, trying again\n", Iface->Adapter);
 483                 Send_DHCPDISCOVER(Iface);
 484                 break;
 485         case STATE_REQUEST_SENT:
 486                 fprintf(stderr, "DHCPREQUEST timeout on %s\n", Iface->Adapter);
 487                 return 1;
 488         default:
 489                 _SysDebug("Timeout with state = %i (%s)", Iface->State, Iface->Adapter);
 490                 return 1;
 491         }
 492         return 0;
 493 }
 494
 495 void Update_State(tInterface *Iface, int newState)
 496 {
 497         if( Iface->State != newState )
 498         {
 499                 Iface->Timeout = _SysTimestamp() + 500;
 500                 Iface->State = newState;
 501                 Iface->nTimeouts = 0;
 502         }
 503         else
 504         {
 505                 // TODO: Exponential backoff
 506                 Iface->Timeout = _SysTimestamp() + 3000;
 507                 Iface->nTimeouts ++;
 508                 _SysDebug("State %i repeated, timeout is 3000ms now", newState);
 509         }
 510 }
 511
 512 void SetAddress(tInterface *Iface, void *Addr, void *Mask, void *Router)
 513 {
 514          int    mask_bits = 0;
 515
 516         // Translate the mask
 517         if( Mask )
 518         {
 519                 uint8_t *mask = Mask;
 520                  int    i;
 521                 _SysDebug("Mask %i.%i.%i.%i", mask[0], mask[1], mask[2], mask[3]);
 522                 for( i = 0; i < 4 && mask[i] == 0xFF; i ++ ) ;
 523                 mask_bits = i*8;
 524                 if( i == 4 )
 525                 {
 526                         // Wut? /32?
 527                 }
 528                 else
 529                 {
 530                         switch(mask[i])
 531                         {
 532                         case 0x00:      mask_bits += 0; break;
 533                         case 0x80:      mask_bits += 1; break;
 534                         case 0xC0:      mask_bits += 2; break;
 535                         case 0xE0:      mask_bits += 3; break;
 536                         case 0xF0:      mask_bits += 4; break;
 537                         case 0xF8:      mask_bits += 5; break;
 538                         case 0xFC:      mask_bits += 6; break;
 539                         case 0xFE:      mask_bits += 7; break;
 540                         default:
 541                                 // Bad mask!
 542                                 break;
 543                         }
 544                 }
 545         }
 546
 547         {
 548                 uint8_t *addr = Addr;
 549                 _SysDebug("Addr %i.%i.%i.%i/%i", addr[0], addr[1], addr[2], addr[3], mask_bits);
 550
 551                 printf("Assigned %i.%i.%i.%i/%i to IF#%i (%s)\n",
 552                         addr[0], addr[1], addr[2], addr[3], mask_bits,
 553                         Iface->Num, Iface->Adapter
 554                         );
 555         }
 556
 557         _SysIOCtl(Iface->IfaceFD, 6, Addr);
 558         _SysIOCtl(Iface->IfaceFD, 7, &mask_bits);
 559
 560         if( Router )
 561         {
 562                 uint8_t *addr = Router;
 563                 _SysDebug("Router %i.%i.%i.%i", addr[0], addr[1], addr[2], addr[3]);
 564
 565                 // Set default route
 566                  int    fd;
 567                 fd = _SysOpen("/Devices/ip/routes/4:00000000:0:0", OPENFLAG_CREATE);
 568                 if(fd == -1) {
 569                         fprintf(stderr, "ERROR: Unable to open default route\n");
 570                 }
 571                 else {
 572                         char ifname[snprintf(NULL,0,"%i",Iface->Num)+1];
 573                         sprintf(ifname, "%i", Iface->Num);
 574                         _SysIOCtl(fd, _SysIOCtl(fd, 3, "set_nexthop"), Router);
 575                         _SysIOCtl(fd, _SysIOCtl(fd, 3, "set_interface"), ifname);
 576                         _SysClose(fd);
 577                 }
 578         }
 579 }
 580