net/net.c

   1 /*
   2  *      Copied from Linux Monitor (LiMon) - Networking.
   3  *
   4  *      Copyright 1994 - 2000 Neil Russell.
   5  *      (See License)
   6  *      Copyright 2000 Roland Borde
   7  *      Copyright 2000 Paolo Scaffardi
   8  *      Copyright 2000-2002 Wolfgang Denk, wd@denx.de
   9  */
  10
  11 /*
  12  * General Desription:
  13  *
  14  * The user interface supports commands for BOOTP, RARP, and TFTP.
  15  * Also, we support ARP internally. Depending on available data,
  16  * these interact as follows:
  17  *
  18  * BOOTP:
  19  *
  20  *      Prerequisites:  - own ethernet address
  21  *      We want:        - own IP address
  22  *                      - TFTP server IP address
  23  *                      - name of bootfile
  24  *      Next step:      ARP
  25  *
  26  * RARP:
  27  *
  28  *      Prerequisites:  - own ethernet address
  29  *      We want:        - own IP address
  30  *                      - TFTP server IP address
  31  *      Next step:      ARP
  32  *
  33  * ARP:
  34  *
  35  *      Prerequisites:  - own ethernet address
  36  *                      - own IP address
  37  *                      - TFTP server IP address
  38  *      We want:        - TFTP server ethernet address
  39  *      Next step:      TFTP
  40  *
  41  * DHCP:
  42  *
  43  *     Prerequisites:   - own ethernet address
  44  *     We want:         - IP, Netmask, ServerIP, Gateway IP
  45  *                      - bootfilename, lease time
  46  *     Next step:       - TFTP
  47  *
  48  * TFTP:
  49  *
  50  *      Prerequisites:  - own ethernet address
  51  *                      - own IP address
  52  *                      - TFTP server IP address
  53  *                      - TFTP server ethernet address
  54  *                      - name of bootfile (if unknown, we use a default name
  55  *                        derived from our own IP address)
  56  *      We want:        - load the boot file
  57  *      Next step:      none
  58  */
  59
  60
  61 #include <common.h>
  62 #include <watchdog.h>
  63 #include <command.h>
  64 #include <net.h>
  65 #include "bootp.h"
  66 #include "tftp.h"
  67 #include "rarp.h"
  68 #include "arp.h"
  69
  70 #if (CONFIG_COMMANDS & CFG_CMD_NET)
  71
  72 #if 0
  73 #define ET_DEBUG
  74 #endif
  75
  76 /** BOOTP EXTENTIONS **/
  77
  78 IPaddr_t        NetOurSubnetMask=0;             /* Our subnet mask (0=unknown)  */
  79 IPaddr_t        NetOurGatewayIP=0;              /* Our gateways IP address      */
  80 IPaddr_t        NetOurDNSIP=0;                  /* Our DNS IP address           */
  81 char            NetOurNISDomain[32]={0,};       /* Our NIS domain               */
  82 char            NetOurHostName[32]={0,};        /* Our hostname                 */
  83 char            NetOurRootPath[64]={0,};        /* Our bootpath                 */
  84 ushort          NetBootFileSize=0;              /* Our bootfile size in blocks  */
  85
  86 /** END OF BOOTP EXTENTIONS **/
  87
  88 ulong           NetBootFileXferSize;    /* The actual transferred size of the bootfile (in bytes) */
  89 uchar           NetOurEther[6];         /* Our ethernet address                 */
  90 uchar           NetServerEther[6] =     /* Boot server enet address             */
  91                         { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
  92 IPaddr_t        NetOurIP;               /* Our IP addr (0 = unknown)            */
  93 IPaddr_t        NetServerIP;            /* Our IP addr (0 = unknown)            */
  94 volatile uchar *NetRxPkt;               /* Current receive packet               */
  95 int             NetRxPktLen;            /* Current rx packet length             */
  96 unsigned        NetIPID;                /* IP packet ID                         */
  97 uchar           NetBcastAddr[6] =       /* Ethernet bcast address               */
  98                         { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
  99 int             NetState;               /* Network loop state                   */
 100 #ifdef CONFIG_NET_MULTI
 101 int             NetRestartWrap = 0;     /* Tried all network devices            */
 102 static int      NetRestarted = 0;       /* Network loop restarted               */
 103 static int      NetDevExists = 0;       /* At least one device configured       */
 104 #endif
 105
 106 char            BootFile[128];          /* Boot File name                       */
 107
 108 volatile uchar  PktBuf[(PKTBUFSRX+1) * PKTSIZE_ALIGN + PKTALIGN];
 109
 110 volatile uchar *NetRxPackets[PKTBUFSRX]; /* Receive packets                     */
 111
 112 static rxhand_f *packetHandler;         /* Current RX packet handler            */
 113 static thand_f *timeHandler;            /* Current timeout handler              */
 114 static ulong    timeValue;              /* Current timeout value                */
 115 volatile uchar *NetTxPacket = 0;        /* THE transmit packet                  */
 116
 117 static int net_check_prereq (proto_t protocol);
 118
 119 /**********************************************************************/
 120 /*
 121  *      Main network processing loop.
 122  */
 123
 124 int
 125 NetLoop(proto_t protocol)
 126 {
 127         DECLARE_GLOBAL_DATA_PTR;
 128
 129         bd_t *bd = gd->bd;
 130
 131 #ifdef CONFIG_NET_MULTI
 132         NetRestarted = 0;
 133         NetDevExists = 0;
 134 #endif
 135
 136         if (!NetTxPacket) {
 137                 int     i;
 138
 139                 /*
 140                  *      Setup packet buffers, aligned correctly.
 141                  */
 142                 NetTxPacket = &PktBuf[0] + (PKTALIGN - 1);
 143                 NetTxPacket -= (ulong)NetTxPacket % PKTALIGN;
 144                 for (i = 0; i < PKTBUFSRX; i++) {
 145                         NetRxPackets[i] = NetTxPacket + (i+1)*PKTSIZE_ALIGN;
 146                 }
 147         }
 148
 149         eth_halt();
 150         eth_init(bd);
 151
 152 restart:
 153 #ifdef CONFIG_NET_MULTI
 154         memcpy (NetOurEther, eth_get_dev()->enetaddr, 6);
 155 #else
 156         memcpy (NetOurEther, bd->bi_enetaddr, 6);
 157 #endif
 158
 159         NetState = NETLOOP_CONTINUE;
 160
 161         /*
 162          *      Start the ball rolling with the given start function.  From
 163          *      here on, this code is a state machine driven by received
 164          *      packets and timer events.
 165          */
 166
 167         switch (protocol) {
 168         case TFTP:
 169                 NetCopyIP(&NetOurIP, &bd->bi_ip_addr);
 170                 NetServerIP     = getenv_IPaddr ("serverip");
 171                 NetOurGatewayIP = getenv_IPaddr ("gatewayip");
 172                 NetOurSubnetMask= getenv_IPaddr ("netmask");
 173                 break;
 174         case BOOTP:
 175         case RARP:
 176                 /*
 177                  * initialize our IP addr to 0 in order to accept ANY
 178                  * IP addr assigned to us by the BOOTP / RARP server
 179                  */
 180                 NetOurIP = 0;
 181                 NetServerIP = 0;
 182                 break;
 183         default:
 184                 break;
 185         }
 186
 187         switch (net_check_prereq (protocol)) {
 188         case 1:
 189                 /* network not configured */
 190                 return 0;
 191
 192 #ifdef CONFIG_NET_MULTI
 193         case 2:
 194                 /* network device not configured */
 195                 break;
 196 #endif /* CONFIG_NET_MULTI */
 197
 198         case 0:
 199 #ifdef CONFIG_NET_MULTI
 200                 NetDevExists = 1;
 201 #endif
 202                 switch (protocol) {
 203                 case TFTP:
 204                         /* always use ARP to get server ethernet address */
 205                         ArpTry = 0;
 206                         ArpRequest ();
 207                         break;
 208
 209 #if (CONFIG_COMMANDS & CFG_CMD_DHCP)
 210                 case DHCP:
 211                         /* Start with a clean slate... */
 212                         NetOurIP = 0;
 213                         NetServerIP = 0;
 214                         DhcpRequest();          /* Basically same as BOOTP */
 215                         break;
 216 #endif /* CFG_CMD_DHCP */
 217
 218                 case BOOTP:
 219                         BootpTry = 0;
 220                         BootpRequest ();
 221                         break;
 222
 223                 case RARP:
 224                         RarpTry = 0;
 225                         RarpRequest ();
 226                         break;
 227                 default:
 228                         break;
 229                 }
 230
 231                 NetBootFileXferSize = 0;
 232                 break;
 233         }
 234
 235
 236         /*
 237          *      Main packet reception loop.  Loop receiving packets until
 238          *      someone sets `NetQuit'.
 239          */
 240         for (;;) {
 241                 WATCHDOG_RESET();
 242 #ifdef CONFIG_SHOW_ACTIVITY
 243                 {
 244                         extern void show_activity(int arg);
 245                         show_activity(1);
 246                 }
 247 #endif
 248                 /*
 249                  *      Check the ethernet for a new packet.  The ethernet
 250                  *      receive routine will process it.
 251                  */
 252                         eth_rx();
 253
 254                 /*
 255                  *      Abort if ctrl-c was pressed.
 256                  */
 257                 if (ctrlc()) {
 258                         eth_halt();
 259                         printf("\nAbort\n");
 260                         return 0;
 261                 }
 262
 263
 264                 /*
 265                  *      Check for a timeout, and run the timeout handler
 266                  *      if we have one.
 267                  */
 268                 if (timeHandler && (get_timer(0) > timeValue)) {
 269                         thand_f *x;
 270
 271                         x = timeHandler;
 272                         timeHandler = (thand_f *)0;
 273                         (*x)();
 274                 }
 275
 276
 277                 switch (NetState) {
 278
 279                 case NETLOOP_RESTART:
 280 #ifdef CONFIG_NET_MULTI
 281                         NetRestarted = 1;
 282 #endif
 283                         goto restart;
 284
 285                 case NETLOOP_SUCCESS:
 286                         if (NetBootFileXferSize > 0) {
 287                                 char buf[10];
 288                                 printf("Bytes transferred = %ld (%lx hex)\n",
 289                                         NetBootFileXferSize,
 290                                         NetBootFileXferSize);
 291                                 sprintf(buf, "%lx", NetBootFileXferSize);
 292                                 setenv("filesize", buf);
 293                         }
 294                         eth_halt();
 295                         return NetBootFileXferSize;
 296
 297                 case NETLOOP_FAIL:
 298                         return 0;
 299                 }
 300         }
 301 }
 302
 303 /**********************************************************************/
 304
 305 static void
 306 startAgainTimeout(void)
 307 {
 308         NetState = NETLOOP_RESTART;
 309 }
 310
 311 static void
 312 startAgainHandler(uchar * pkt, unsigned dest, unsigned src, unsigned len)
 313 {
 314         /* Totally ignore the packet */
 315 }
 316
 317 void
 318 NetStartAgain(void)
 319 {
 320 #ifndef CONFIG_NET_MULTI
 321         NetSetTimeout(10 * CFG_HZ, startAgainTimeout);
 322         NetSetHandler(startAgainHandler);
 323 #else
 324         DECLARE_GLOBAL_DATA_PTR;
 325
 326         eth_halt();
 327         eth_try_another(!NetRestarted);
 328         eth_init(gd->bd);
 329         if (NetRestartWrap)
 330         {
 331                 NetRestartWrap = 0;
 332                 if (NetDevExists)
 333                 {
 334                         NetSetTimeout(10 * CFG_HZ, startAgainTimeout);
 335                         NetSetHandler(startAgainHandler);
 336                 }
 337                 else
 338                 {
 339                         NetState = NETLOOP_FAIL;
 340                 }
 341         }
 342         else
 343         {
 344                 NetState = NETLOOP_RESTART;
 345         }
 346 #endif
 347 }
 348
 349 /**********************************************************************/
 350 /*
 351  *      Miscelaneous bits.
 352  */
 353
 354 void
 355 NetSetHandler(rxhand_f * f)
 356 {
 357         packetHandler = f;
 358 }
 359
 360
 361 void
 362 NetSetTimeout(int iv, thand_f * f)
 363 {
 364         if (iv == 0) {
 365                 timeHandler = (thand_f *)0;
 366         } else {
 367                 timeHandler = f;
 368                 timeValue = get_timer(0) + iv;
 369         }
 370 }
 371
 372
 373 void
 374 NetSendPacket(volatile uchar * pkt, int len)
 375 {
 376         (void) eth_send(pkt, len);
 377 }
 378
 379
 380
 381 void
 382 NetReceive(volatile uchar * pkt, int len)
 383 {
 384         Ethernet_t *et;
 385         IP_t    *ip;
 386         ARP_t   *arp;
 387         IPaddr_t tmp;
 388         int     x;
 389
 390
 391         NetRxPkt = pkt;
 392         NetRxPktLen = len;
 393         et = (Ethernet_t *)pkt;
 394
 395         x = ntohs(et->et_protlen);
 396
 397         if (x < 1514) {
 398                 /*
 399                  *      Got a 802 packet.  Check the other protocol field.
 400                  */
 401                 x = ntohs(et->et_prot);
 402                 ip = (IP_t *)(pkt + E802_HDR_SIZE);
 403                 len -= E802_HDR_SIZE;
 404         } else {
 405                 ip = (IP_t *)(pkt + ETHER_HDR_SIZE);
 406                 len -= ETHER_HDR_SIZE;
 407         }
 408
 409 #ifdef ET_DEBUG
 410         printf("Receive from protocol 0x%x\n", x);
 411 #endif
 412
 413         switch (x) {
 414
 415         case PROT_ARP:
 416                 /*
 417                  * We have to deal with two types of ARP packets:
 418                  * - REQUEST packets will be answered by sending  our
 419                  *   IP address - if we know it.
 420                  * - REPLY packates are expected only after we asked
 421                  *   for the TFTP server's or the gateway's ethernet
 422                  *   address; so if we receive such a packet, we set
 423                  *   the server ethernet address
 424                  */
 425 #ifdef ET_DEBUG
 426                 printf("Got ARP\n");
 427 #endif
 428                 arp = (ARP_t *)ip;
 429                 if (len < ARP_HDR_SIZE) {
 430                         printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
 431                         return;
 432                 }
 433                 if (ntohs(arp->ar_hrd) != ARP_ETHER) {
 434                         return;
 435                 }
 436                 if (ntohs(arp->ar_pro) != PROT_IP) {
 437                         return;
 438                 }
 439                 if (arp->ar_hln != 6) {
 440                         return;
 441                 }
 442                 if (arp->ar_pln != 4) {
 443                         return;
 444                 }
 445
 446                 if (NetOurIP == 0) {
 447                         return;
 448                 }
 449
 450                 if (NetReadIP(&arp->ar_data[16]) != NetOurIP) {
 451                         return;
 452                 }
 453
 454                 switch (ntohs(arp->ar_op)) {
 455                 case ARPOP_REQUEST:             /* reply with our IP address    */
 456 #ifdef ET_DEBUG
 457                         printf("Got ARP REQUEST, return our IP\n");
 458 #endif
 459                         NetSetEther((uchar *)et, et->et_src, PROT_ARP);
 460                         arp->ar_op = htons(ARPOP_REPLY);
 461                         memcpy   (&arp->ar_data[10], &arp->ar_data[0], 6);
 462                         NetCopyIP(&arp->ar_data[16], &arp->ar_data[6]);
 463                         memcpy   (&arp->ar_data[ 0], NetOurEther, 6);
 464                         NetCopyIP(&arp->ar_data[ 6], &NetOurIP);
 465                         NetSendPacket((uchar *)et,((uchar *)arp-pkt)+ARP_HDR_SIZE);
 466                         return;
 467                 case ARPOP_REPLY:               /* set TFTP server eth addr     */
 468 #ifdef ET_DEBUG
 469                         printf("Got ARP REPLY, set server/gtwy eth addr\n");
 470 #endif
 471                         memcpy (NetServerEther, &arp->ar_data[0], 6);
 472                         (*packetHandler)(0,0,0,0);      /* start TFTP */
 473                         return;
 474                 default:
 475 #ifdef ET_DEBUG
 476                         printf("Unexpected ARP opcode 0x%x\n", ntohs(arp->ar_op));
 477 #endif
 478                         return;
 479                 }
 480
 481         case PROT_RARP:
 482 #ifdef ET_DEBUG
 483                 printf("Got RARP\n");
 484 #endif
 485                 arp = (ARP_t *)ip;
 486                 if (len < ARP_HDR_SIZE) {
 487                         printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
 488                         return;
 489                 }
 490
 491                 if ((ntohs(arp->ar_op) != RARPOP_REPLY) ||
 492                         (ntohs(arp->ar_hrd) != ARP_ETHER)   ||
 493                         (ntohs(arp->ar_pro) != PROT_IP)     ||
 494                         (arp->ar_hln != 6) || (arp->ar_pln != 4)) {
 495
 496                         printf("invalid RARP header\n");
 497                 } else {
 498                         NetCopyIP(&NetOurIP,    &arp->ar_data[16]);
 499                         NetCopyIP(&NetServerIP, &arp->ar_data[ 6]);
 500                         memcpy (NetServerEther, &arp->ar_data[ 0], 6);
 501
 502                         (*packetHandler)(0,0,0,0);
 503                 }
 504                 break;
 505
 506         case PROT_IP:
 507 #ifdef ET_DEBUG
 508                 printf("Got IP\n");
 509 #endif
 510                 if (len < IP_HDR_SIZE) {
 511                         debug ("len bad %d < %d\n", len, IP_HDR_SIZE);
 512                         return;
 513                 }
 514                 if (len < ntohs(ip->ip_len)) {
 515                         printf("len bad %d < %d\n", len, ntohs(ip->ip_len));
 516                         return;
 517                 }
 518                 len = ntohs(ip->ip_len);
 519 #ifdef ET_DEBUG
 520                 printf("len=%d, v=%02x\n", len, ip->ip_hl_v & 0xff);
 521 #endif
 522                 if ((ip->ip_hl_v & 0xf0) != 0x40) {
 523                         return;
 524                 }
 525                 if (ip->ip_off & htons(0x1fff)) { /* Can't deal w/ fragments */
 526                         return;
 527                 }
 528                 if (!NetCksumOk((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2)) {
 529                         printf("checksum bad\n");
 530                         return;
 531                 }
 532                 tmp = NetReadIP(&ip->ip_dst);
 533                 if (NetOurIP && tmp != NetOurIP && tmp != 0xFFFFFFFF) {
 534                         return;
 535                 }
 536                 /*
 537                  * watch for ICMP host redirects
 538                  *
 539                  * There is no real handler code (yet). We just watch
 540                  * for ICMP host redirect messages. In case anybody
 541                  * sees these messages: please contact me
 542                  * (wd@denx.de), or - even better - send me the
 543                  * necessary fixes :-)
 544                  *
 545                  * Note: in all cases where I have seen this so far
 546                  * it was a problem with the router configuration,
 547                  * for instance when a router was configured in the
 548                  * BOOTP reply, but the TFTP server was on the same
 549                  * subnet. So this is probably a warning that your
 550                  * configuration might be wrong. But I'm not really
 551                  * sure if there aren't any other situations.
 552                  */
 553                 if (ip->ip_p == IPPROTO_ICMP) {
 554                         ICMP_t *icmph = (ICMP_t *)&(ip->udp_src);
 555
 556                         if (icmph->type != ICMP_REDIRECT)
 557                                 return;
 558                         if (icmph->code != ICMP_REDIR_HOST)
 559                                 return;
 560                         puts (" ICMP Host Redirect to ");
 561                         print_IPaddr(icmph->un.gateway);
 562                         putc(' ');
 563                 } else if (ip->ip_p != IPPROTO_UDP) {   /* Only UDP packets */
 564                         return;
 565                 }
 566
 567                 /*
 568                  *      IP header OK.  Pass the packet to the current handler.
 569                  */
 570                 (*packetHandler)((uchar *)ip +IP_HDR_SIZE,
 571                                                 ntohs(ip->udp_dst),
 572                                                 ntohs(ip->udp_src),
 573                                                 ntohs(ip->udp_len) - 8);
 574
 575                 break;
 576         }
 577 }
 578
 579
 580 /**********************************************************************/
 581
 582 static int net_check_prereq (proto_t protocol)
 583 {
 584         switch (protocol) {
 585         case ARP:       /* nothing to do */
 586                         break;
 587
 588         case TFTP:
 589                         if (NetServerIP == 0) {
 590                                 puts ("*** ERROR: `serverip' not set\n");
 591                                 return (1);
 592                         }
 593
 594                         if (NetOurIP == 0) {
 595                                 puts ("*** ERROR: `ipaddr' not set\n");
 596                                 return (1);
 597                         }
 598                         /* Fall through */
 599
 600         case DHCP:
 601         case RARP:
 602         case BOOTP:
 603                         if (memcmp(NetOurEther, "\0\0\0\0\0\0", 6) == 0) {
 604 #ifdef CONFIG_NET_MULTI
 605                             extern int eth_get_dev_index (void);
 606                             int num = eth_get_dev_index();
 607
 608                             switch (num) {
 609                             case -1:
 610                                 puts ("*** ERROR: No ethernet found.\n");
 611                                 return (1);
 612                             case 0:
 613                                 puts ("*** ERROR: `ethaddr' not set\n");
 614                                 break;
 615                             default:
 616                                 printf ("*** ERROR: `eth%daddr' not set\n",
 617                                         num);
 618                                 break;
 619                             }
 620
 621                             NetStartAgain ();
 622                             return (2);
 623 #else
 624                             puts ("*** ERROR: `ethaddr' not set\n");
 625                             return (1);
 626 #endif
 627                         }
 628                         /* Fall through */
 629         }
 630         return (0);     /* OK */
 631 }
 632 /**********************************************************************/
 633
 634 int
 635 NetCksumOk(uchar * ptr, int len)
 636 {
 637         return !((NetCksum(ptr, len) + 1) & 0xfffe);
 638 }
 639
 640
 641 unsigned
 642 NetCksum(uchar * ptr, int len)
 643 {
 644         ulong   xsum;
 645
 646         xsum = 0;
 647         while (len-- > 0)
 648                 xsum += *((ushort *)ptr)++;
 649         xsum = (xsum & 0xffff) + (xsum >> 16);
 650         xsum = (xsum & 0xffff) + (xsum >> 16);
 651         return (xsum & 0xffff);
 652 }
 653
 654
 655 void
 656 NetSetEther(volatile uchar * xet, uchar * addr, uint prot)
 657 {
 658         Ethernet_t *et = (Ethernet_t *)xet;
 659
 660         memcpy (et->et_dest, addr, 6);
 661         memcpy (et->et_src, NetOurEther, 6);
 662         et->et_protlen = htons(prot);
 663 }
 664
 665
 666 void
 667 NetSetIP(volatile uchar * xip, IPaddr_t dest, int dport, int sport, int len)
 668 {
 669         volatile IP_t *ip = (IP_t *)xip;
 670
 671         /*
 672          *      If the data is an odd number of bytes, zero the
 673          *      byte after the last byte so that the checksum
 674          *      will work.
 675          */
 676         if (len & 1)
 677                 xip[IP_HDR_SIZE + len] = 0;
 678
 679         /*
 680          *      Construct an IP and UDP header.
 681                         (need to set no fragment bit - XXX)
 682          */
 683         ip->ip_hl_v  = 0x45;            /* IP_HDR_SIZE / 4 (not including UDP) */
 684         ip->ip_tos   = 0;
 685         ip->ip_len   = htons(IP_HDR_SIZE + len);
 686         ip->ip_id    = htons(NetIPID++);
 687         ip->ip_off   = htons(0x4000);   /* No fragmentation */
 688         ip->ip_ttl   = 255;
 689         ip->ip_p     = 17;              /* UDP */
 690         ip->ip_sum   = 0;
 691         NetCopyIP((void*)&ip->ip_src, &NetOurIP); /* already in network byte order */
 692         NetCopyIP((void*)&ip->ip_dst, &dest);      /* - "" - */
 693         ip->udp_src  = htons(sport);
 694         ip->udp_dst  = htons(dport);
 695         ip->udp_len  = htons(8 + len);
 696         ip->udp_xsum = 0;
 697         ip->ip_sum   = ~NetCksum((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2);
 698 }
 699
 700 void copy_filename (uchar *dst, uchar *src, int size)
 701 {
 702         if (*src && (*src == '"')) {
 703                 ++src;
 704                 --size;
 705         }
 706
 707         while ((--size > 0) && *src && (*src != '"')) {
 708                 *dst++ = *src++;
 709         }
 710         *dst = '\0';
 711 }
 712
 713 #endif /* CFG_CMD_NET */
 714
 715 void ip_to_string (IPaddr_t x, char *s)
 716 {
 717     x = ntohl(x);
 718     sprintf (s,"%d.%d.%d.%d",
 719         (int)((x >> 24) & 0xff),
 720         (int)((x >> 16) & 0xff),
 721         (int)((x >>  8) & 0xff),
 722         (int)((x >>  0) & 0xff)
 723     );
 724 }
 725
 726 void print_IPaddr (IPaddr_t x)
 727 {
 728     char tmp[16];
 729
 730     ip_to_string(x, tmp);
 731
 732     puts(tmp);
 733 }
 734
 735 IPaddr_t getenv_IPaddr (char *var)
 736 {
 737         IPaddr_t addr;
 738         char *s, *e;
 739         int i;
 740
 741         s = getenv (var);
 742
 743         for (addr=0, i=0; i<4; ++i) {
 744                 ulong val = s ? simple_strtoul(s, &e, 10) : 0;
 745                 addr <<= 8;
 746                 addr |= (val & 0xFF);
 747                 if (s) {
 748                         s = (*e) ? e+1 : e;
 749                 }
 750         }
 751
 752         return (htonl(addr));
 753 }