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