include/net.h

   1 /*
   2  *      LiMon Monitor (LiMon) - Network.
   3  *
   4  *      Copyright 1994 - 2000 Neil Russell.
   5  *      (See License)
   6  *
   7  *
   8  * History
   9  *      9/16/00   bor  adapted to TQM823L/STK8xxL board, RARP/TFTP boot added
  10  */
  11
  12 #ifndef __NET_H__
  13 #define __NET_H__
  14
  15 #if defined(CONFIG_8xx)
  16 #include <commproc.h>
  17 #endif  /* CONFIG_8xx */
  18
  19 #include <asm/cache.h>
  20 #include <asm/byteorder.h>      /* for nton* / ntoh* stuff */
  21
  22
  23 /*
  24  *      The number of receive packet buffers, and the required packet buffer
  25  *      alignment in memory.
  26  *
  27  */
  28
  29 #ifdef CONFIG_SYS_RX_ETH_BUFFER
  30 # define PKTBUFSRX      CONFIG_SYS_RX_ETH_BUFFER
  31 #else
  32 # define PKTBUFSRX      4
  33 #endif
  34
  35 #define PKTALIGN        ARCH_DMA_MINALIGN
  36
  37 /* IPv4 addresses are always 32 bits in size */
  38 typedef u32             IPaddr_t;
  39
  40
  41 /**
  42  * An incoming packet handler.
  43  * @param pkt    pointer to the application packet
  44  * @param dport  destination UDP port
  45  * @param sip    source IP address
  46  * @param sport  source UDP port
  47  * @param len    packet length
  48  */
  49 typedef void rxhand_f(uchar *pkt, unsigned dport,
  50                       IPaddr_t sip, unsigned sport,
  51                       unsigned len);
  52
  53 /**
  54  * An incoming ICMP packet handler.
  55  * @param type  ICMP type
  56  * @param code  ICMP code
  57  * @param dport destination UDP port
  58  * @param sip   source IP address
  59  * @param sport source UDP port
  60  * @param pkt   pointer to the ICMP packet data
  61  * @param len   packet length
  62  */
  63 typedef void rxhand_icmp_f(unsigned type, unsigned code, unsigned dport,
  64                 IPaddr_t sip, unsigned sport, uchar *pkt, unsigned len);
  65
  66 /*
  67  *      A timeout handler.  Called after time interval has expired.
  68  */
  69 typedef void    thand_f(void);
  70
  71 enum eth_state_t {
  72         ETH_STATE_INIT,
  73         ETH_STATE_PASSIVE,
  74         ETH_STATE_ACTIVE
  75 };
  76
  77 struct eth_device {
  78         char name[16];
  79         unsigned char enetaddr[6];
  80         int iobase;
  81         int state;
  82
  83         int  (*init) (struct eth_device *, bd_t *);
  84         int  (*send) (struct eth_device *, void *packet, int length);
  85         int  (*recv) (struct eth_device *);
  86         void (*halt) (struct eth_device *);
  87 #ifdef CONFIG_MCAST_TFTP
  88         int (*mcast) (struct eth_device *, u32 ip, u8 set);
  89 #endif
  90         int  (*write_hwaddr) (struct eth_device *);
  91         struct eth_device *next;
  92         int index;
  93         void *priv;
  94 };
  95
  96 extern int eth_initialize(bd_t *bis);   /* Initialize network subsystem */
  97 extern int eth_register(struct eth_device* dev);/* Register network device */
  98 extern int eth_unregister(struct eth_device *dev);/* Remove network device */
  99 extern void eth_try_another(int first_restart); /* Change the device */
 100 extern void eth_set_current(void);              /* set nterface to ethcur var */
 101 extern struct eth_device *eth_get_dev(void);    /* get the current device MAC */
 102 extern struct eth_device *eth_get_dev_by_name(const char *devname);
 103 extern struct eth_device *eth_get_dev_by_index(int index); /* get dev @ index */
 104 extern int eth_get_dev_index(void);             /* get the device index */
 105 extern void eth_parse_enetaddr(const char *addr, uchar *enetaddr);
 106 extern int eth_getenv_enetaddr(char *name, uchar *enetaddr);
 107 extern int eth_setenv_enetaddr(char *name, const uchar *enetaddr);
 108
 109 /*
 110  * Get the hardware address for an ethernet interface .
 111  * Args:
 112  *      base_name - base name for device (normally "eth")
 113  *      index - device index number (0 for first)
 114  *      enetaddr - returns 6 byte hardware address
 115  * Returns:
 116  *      Return true if the address is valid.
 117  */
 118 extern int eth_getenv_enetaddr_by_index(const char *base_name, int index,
 119                                         uchar *enetaddr);
 120
 121 extern int usb_eth_initialize(bd_t *bi);
 122 extern int eth_init(bd_t *bis);                 /* Initialize the device */
 123 extern int eth_send(void *packet, int length);     /* Send a packet */
 124
 125 #ifdef CONFIG_API
 126 extern int eth_receive(void *packet, int length); /* Receive a packet*/
 127 extern void (*push_packet)(void *packet, int length);
 128 #endif
 129 extern int eth_rx(void);                        /* Check for received packets */
 130 extern void eth_halt(void);                     /* stop SCC */
 131 extern char *eth_get_name(void);                /* get name of current device */
 132
 133 /*
 134  * Set the hardware address for an ethernet interface based on 'eth%daddr'
 135  * environment variable (or just 'ethaddr' if eth_number is 0).
 136  * Args:
 137  *      base_name - base name for device (normally "eth")
 138  *      eth_number - value of %d (0 for first device of this type)
 139  * Returns:
 140  *      0 is success, non-zero is error status from driver.
 141  */
 142 int eth_write_hwaddr(struct eth_device *dev, const char *base_name,
 143                      int eth_number);
 144
 145 #ifdef CONFIG_MCAST_TFTP
 146 int eth_mcast_join(IPaddr_t mcast_addr, u8 join);
 147 u32 ether_crc(size_t len, unsigned char const *p);
 148 #endif
 149
 150
 151 /**********************************************************************/
 152 /*
 153  *      Protocol headers.
 154  */
 155
 156 /*
 157  *      Ethernet header
 158  */
 159
 160 struct ethernet_hdr {
 161         uchar           et_dest[6];     /* Destination node             */
 162         uchar           et_src[6];      /* Source node                  */
 163         ushort          et_protlen;     /* Protocol or length           */
 164 };
 165
 166 /* Ethernet header size */
 167 #define ETHER_HDR_SIZE  (sizeof(struct ethernet_hdr))
 168
 169 struct e802_hdr {
 170         uchar           et_dest[6];     /* Destination node             */
 171         uchar           et_src[6];      /* Source node                  */
 172         ushort          et_protlen;     /* Protocol or length           */
 173         uchar           et_dsap;        /* 802 DSAP                     */
 174         uchar           et_ssap;        /* 802 SSAP                     */
 175         uchar           et_ctl;         /* 802 control                  */
 176         uchar           et_snap1;       /* SNAP                         */
 177         uchar           et_snap2;
 178         uchar           et_snap3;
 179         ushort          et_prot;        /* 802 protocol                 */
 180 };
 181
 182 /* 802 + SNAP + ethernet header size */
 183 #define E802_HDR_SIZE   (sizeof(struct e802_hdr))
 184
 185 /*
 186  *      Virtual LAN Ethernet header
 187  */
 188 struct vlan_ethernet_hdr {
 189         uchar           vet_dest[6];    /* Destination node             */
 190         uchar           vet_src[6];     /* Source node                  */
 191         ushort          vet_vlan_type;  /* PROT_VLAN                    */
 192         ushort          vet_tag;        /* TAG of VLAN                  */
 193         ushort          vet_type;       /* protocol type                */
 194 };
 195
 196 /* VLAN Ethernet header size */
 197 #define VLAN_ETHER_HDR_SIZE     (sizeof(struct vlan_ethernet_hdr))
 198
 199 #define PROT_IP         0x0800          /* IP protocol                  */
 200 #define PROT_ARP        0x0806          /* IP ARP protocol              */
 201 #define PROT_RARP       0x8035          /* IP ARP protocol              */
 202 #define PROT_VLAN       0x8100          /* IEEE 802.1q protocol         */
 203
 204 #define IPPROTO_ICMP     1      /* Internet Control Message Protocol    */
 205 #define IPPROTO_UDP     17      /* User Datagram Protocol               */
 206
 207 /*
 208  *      Internet Protocol (IP) header.
 209  */
 210 struct ip_hdr {
 211         uchar           ip_hl_v;        /* header length and version    */
 212         uchar           ip_tos;         /* type of service              */
 213         ushort          ip_len;         /* total length                 */
 214         ushort          ip_id;          /* identification               */
 215         ushort          ip_off;         /* fragment offset field        */
 216         uchar           ip_ttl;         /* time to live                 */
 217         uchar           ip_p;           /* protocol                     */
 218         ushort          ip_sum;         /* checksum                     */
 219         IPaddr_t        ip_src;         /* Source IP address            */
 220         IPaddr_t        ip_dst;         /* Destination IP address       */
 221 };
 222
 223 #define IP_OFFS         0x1fff /* ip offset *= 8 */
 224 #define IP_FLAGS        0xe000 /* first 3 bits */
 225 #define IP_FLAGS_RES    0x8000 /* reserved */
 226 #define IP_FLAGS_DFRAG  0x4000 /* don't fragments */
 227 #define IP_FLAGS_MFRAG  0x2000 /* more fragments */
 228
 229 #define IP_HDR_SIZE             (sizeof(struct ip_hdr))
 230
 231 /*
 232  *      Internet Protocol (IP) + UDP header.
 233  */
 234 struct ip_udp_hdr {
 235         uchar           ip_hl_v;        /* header length and version    */
 236         uchar           ip_tos;         /* type of service              */
 237         ushort          ip_len;         /* total length                 */
 238         ushort          ip_id;          /* identification               */
 239         ushort          ip_off;         /* fragment offset field        */
 240         uchar           ip_ttl;         /* time to live                 */
 241         uchar           ip_p;           /* protocol                     */
 242         ushort          ip_sum;         /* checksum                     */
 243         IPaddr_t        ip_src;         /* Source IP address            */
 244         IPaddr_t        ip_dst;         /* Destination IP address       */
 245         ushort          udp_src;        /* UDP source port              */
 246         ushort          udp_dst;        /* UDP destination port         */
 247         ushort          udp_len;        /* Length of UDP packet         */
 248         ushort          udp_xsum;       /* Checksum                     */
 249 };
 250
 251 #define IP_UDP_HDR_SIZE         (sizeof(struct ip_udp_hdr))
 252 #define UDP_HDR_SIZE            (IP_UDP_HDR_SIZE - IP_HDR_SIZE)
 253
 254 /*
 255  *      Address Resolution Protocol (ARP) header.
 256  */
 257 struct arp_hdr {
 258         ushort          ar_hrd;         /* Format of hardware address   */
 259 #   define ARP_ETHER        1           /* Ethernet  hardware address   */
 260         ushort          ar_pro;         /* Format of protocol address   */
 261         uchar           ar_hln;         /* Length of hardware address   */
 262 #   define ARP_HLEN     6
 263         uchar           ar_pln;         /* Length of protocol address   */
 264 #   define ARP_PLEN     4
 265         ushort          ar_op;          /* Operation                    */
 266 #   define ARPOP_REQUEST    1           /* Request  to resolve  address */
 267 #   define ARPOP_REPLY      2           /* Response to previous request */
 268
 269 #   define RARPOP_REQUEST   3           /* Request  to resolve  address */
 270 #   define RARPOP_REPLY     4           /* Response to previous request */
 271
 272         /*
 273          * The remaining fields are variable in size, according to
 274          * the sizes above, and are defined as appropriate for
 275          * specific hardware/protocol combinations.
 276          */
 277         uchar           ar_data[0];
 278 #define ar_sha          ar_data[0]
 279 #define ar_spa          ar_data[ARP_HLEN]
 280 #define ar_tha          ar_data[ARP_HLEN + ARP_PLEN]
 281 #define ar_tpa          ar_data[ARP_HLEN + ARP_PLEN + ARP_HLEN]
 282 #if 0
 283         uchar           ar_sha[];       /* Sender hardware address      */
 284         uchar           ar_spa[];       /* Sender protocol address      */
 285         uchar           ar_tha[];       /* Target hardware address      */
 286         uchar           ar_tpa[];       /* Target protocol address      */
 287 #endif /* 0 */
 288 };
 289
 290 #define ARP_HDR_SIZE    (8+20)          /* Size assuming ethernet       */
 291
 292 /*
 293  * ICMP stuff (just enough to handle (host) redirect messages)
 294  */
 295 #define ICMP_ECHO_REPLY         0       /* Echo reply                   */
 296 #define ICMP_NOT_REACH          3       /* Detination unreachable       */
 297 #define ICMP_REDIRECT           5       /* Redirect (change route)      */
 298 #define ICMP_ECHO_REQUEST       8       /* Echo request                 */
 299
 300 /* Codes for REDIRECT. */
 301 #define ICMP_REDIR_NET          0       /* Redirect Net                 */
 302 #define ICMP_REDIR_HOST         1       /* Redirect Host                */
 303
 304 /* Codes for NOT_REACH */
 305 #define ICMP_NOT_REACH_PORT     3       /* Port unreachable             */
 306
 307 struct icmp_hdr {
 308         uchar           type;
 309         uchar           code;
 310         ushort          checksum;
 311         union {
 312                 struct {
 313                         ushort  id;
 314                         ushort  sequence;
 315                 } echo;
 316                 ulong   gateway;
 317                 struct {
 318                         ushort  __unused;
 319                         ushort  mtu;
 320                 } frag;
 321                 uchar data[0];
 322         } un;
 323 };
 324
 325 #define ICMP_HDR_SIZE           (sizeof(struct icmp_hdr))
 326 #define IP_ICMP_HDR_SIZE        (IP_HDR_SIZE + ICMP_HDR_SIZE)
 327
 328 /*
 329  * Maximum packet size; used to allocate packet storage.
 330  * TFTP packets can be 524 bytes + IP header + ethernet header.
 331  * Lets be conservative, and go for 38 * 16.  (Must also be
 332  * a multiple of 32 bytes).
 333  */
 334 /*
 335  * AS.HARNOIS : Better to set PKTSIZE to maximum size because
 336  * traffic type is not always controlled
 337  * maximum packet size =  1518
 338  * maximum packet size and multiple of 32 bytes =  1536
 339  */
 340 #define PKTSIZE                 1518
 341 #define PKTSIZE_ALIGN           1536
 342 /*#define PKTSIZE               608*/
 343
 344 /*
 345  * Maximum receive ring size; that is, the number of packets
 346  * we can buffer before overflow happens. Basically, this just
 347  * needs to be enough to prevent a packet being discarded while
 348  * we are processing the previous one.
 349  */
 350 #define RINGSZ          4
 351 #define RINGSZ_LOG2     2
 352
 353 /**********************************************************************/
 354 /*
 355  *      Globals.
 356  *
 357  * Note:
 358  *
 359  * All variables of type IPaddr_t are stored in NETWORK byte order
 360  * (big endian).
 361  */
 362
 363 /* net.c */
 364 /** BOOTP EXTENTIONS **/
 365 extern IPaddr_t NetOurGatewayIP;        /* Our gateway IP address */
 366 extern IPaddr_t NetOurSubnetMask;       /* Our subnet mask (0 = unknown) */
 367 extern IPaddr_t NetOurDNSIP;    /* Our Domain Name Server (0 = unknown) */
 368 #if defined(CONFIG_BOOTP_DNS2)
 369 extern IPaddr_t NetOurDNS2IP;   /* Our 2nd Domain Name Server (0 = unknown) */
 370 #endif
 371 extern char     NetOurNISDomain[32];    /* Our NIS domain */
 372 extern char     NetOurHostName[32];     /* Our hostname */
 373 extern char     NetOurRootPath[64];     /* Our root path */
 374 extern ushort   NetBootFileSize;        /* Our boot file size in blocks */
 375 /** END OF BOOTP EXTENTIONS **/
 376 extern ulong            NetBootFileXferSize;    /* size of bootfile in bytes */
 377 extern uchar            NetOurEther[6];         /* Our ethernet address */
 378 extern uchar            NetServerEther[6];      /* Boot server enet address */
 379 extern IPaddr_t         NetOurIP;       /* Our    IP addr (0 = unknown) */
 380 extern IPaddr_t         NetServerIP;    /* Server IP addr (0 = unknown) */
 381 extern uchar            *NetTxPacket;           /* THE transmit packet */
 382 extern uchar            *NetRxPackets[PKTBUFSRX]; /* Receive packets */
 383 extern uchar            *NetRxPacket;           /* Current receive packet */
 384 extern int              NetRxPacketLen;         /* Current rx packet length */
 385 extern unsigned         NetIPID;                /* IP ID (counting) */
 386 extern uchar            NetBcastAddr[6];        /* Ethernet boardcast address */
 387 extern uchar            NetEtherNullAddr[6];
 388
 389 #define VLAN_NONE       4095                    /* untagged */
 390 #define VLAN_IDMASK     0x0fff                  /* mask of valid vlan id */
 391 extern ushort           NetOurVLAN;             /* Our VLAN */
 392 extern ushort           NetOurNativeVLAN;       /* Our Native VLAN */
 393
 394 extern int              NetState;               /* Network loop state */
 395 #define NETLOOP_CONTINUE        1
 396 #define NETLOOP_RESTART         2
 397 #define NETLOOP_SUCCESS         3
 398 #define NETLOOP_FAIL            4
 399
 400 extern int              NetRestartWrap;         /* Tried all network devices */
 401
 402 enum proto_t {
 403         BOOTP, RARP, ARP, TFTPGET, DHCP, PING, DNS, NFS, CDP, NETCONS, SNTP,
 404         TFTPSRV, TFTPPUT
 405 };
 406
 407 /* from net/net.c */
 408 extern char     BootFile[128];                  /* Boot File name */
 409
 410 #if defined(CONFIG_CMD_DNS)
 411 extern char *NetDNSResolve;             /* The host to resolve  */
 412 extern char *NetDNSenvvar;              /* the env var to put the ip into */
 413 #endif
 414
 415 #if defined(CONFIG_CMD_PING)
 416 extern IPaddr_t NetPingIP;                      /* the ip address to ping */
 417 #endif
 418
 419 #if defined(CONFIG_CMD_CDP)
 420 /* when CDP completes these hold the return values */
 421 extern ushort CDPNativeVLAN;            /* CDP returned native VLAN */
 422 extern ushort CDPApplianceVLAN;         /* CDP returned appliance VLAN */
 423
 424 /*
 425  * Check for a CDP packet by examining the received MAC address field
 426  */
 427 static inline int is_cdp_packet(const uchar *et_addr)
 428 {
 429         extern const uchar NetCDPAddr[6];
 430
 431         return memcmp(et_addr, NetCDPAddr, 6) == 0;
 432 }
 433 #endif
 434
 435 #if defined(CONFIG_CMD_SNTP)
 436 extern IPaddr_t NetNtpServerIP;                 /* the ip address to NTP */
 437 extern int NetTimeOffset;                       /* offset time from UTC */
 438 #endif
 439
 440 #if defined(CONFIG_MCAST_TFTP)
 441 extern IPaddr_t Mcast_addr;
 442 #endif
 443
 444 /* Initialize the network adapter */
 445 extern int NetLoop(enum proto_t);
 446
 447 /* Shutdown adapters and cleanup */
 448 extern void     NetStop(void);
 449
 450 /* Load failed.  Start again. */
 451 extern void     NetStartAgain(void);
 452
 453 /* Get size of the ethernet header when we send */
 454 extern int      NetEthHdrSize(void);
 455
 456 /* Set ethernet header; returns the size of the header */
 457 extern int NetSetEther(uchar *, uchar *, uint);
 458
 459 /* Set IP header */
 460 extern void net_set_ip_header(uchar *pkt, IPaddr_t dest, IPaddr_t source);
 461 extern void net_set_udp_header(uchar *pkt, IPaddr_t dest, int dport,
 462                                 int sport, int len);
 463
 464 /* Checksum */
 465 extern int      NetCksumOk(uchar *, int);       /* Return true if cksum OK */
 466 extern uint     NetCksum(uchar *, int);         /* Calculate the checksum */
 467
 468 /* Callbacks */
 469 extern rxhand_f *NetGetHandler(void);           /* Get RX packet handler */
 470 extern void     NetSetHandler(rxhand_f *);      /* Set RX packet handler */
 471 extern void net_set_icmp_handler(rxhand_icmp_f *f); /* Set ICMP RX handler */
 472 extern void     NetSetTimeout(ulong, thand_f *);/* Set timeout handler */
 473
 474 /* Transmit "NetTxPacket" */
 475 extern void NetSendPacket(uchar *, int);
 476
 477 /*
 478  * Transmit UDP packet, performing ARP request if needed
 479  *
 480  * @param ether Raw packet buffer
 481  * @param dest IP address to send the datagram to
 482  * @param dport Destination UDP port
 483  * @param sport Source UDP port
 484  * @param payload_len Length of data after the UDP header
 485  */
 486 extern int      NetSendUDPPacket(uchar *ether, IPaddr_t dest, int dport,
 487                         int sport, int payload_len);
 488
 489 /* Processes a received packet */
 490 extern void NetReceive(uchar *, int);
 491
 492 #ifdef CONFIG_NETCONSOLE
 493 void NcStart(void);
 494 int nc_input_packet(uchar *pkt, unsigned dest, unsigned src, unsigned len);
 495 #endif
 496
 497 /*
 498  * Check if autoload is enabled. If so, use either NFS or TFTP to download
 499  * the boot file.
 500  */
 501 void net_auto_load(void);
 502
 503 /*
 504  * The following functions are a bit ugly, but necessary to deal with
 505  * alignment restrictions on ARM.
 506  *
 507  * We're using inline functions, which had the smallest memory
 508  * footprint in our tests.
 509  */
 510 /* return IP *in network byteorder* */
 511 static inline IPaddr_t NetReadIP(void *from)
 512 {
 513         IPaddr_t ip;
 514
 515         memcpy((void *)&ip, (void *)from, sizeof(ip));
 516         return ip;
 517 }
 518
 519 /* return ulong *in network byteorder* */
 520 static inline ulong NetReadLong(ulong *from)
 521 {
 522         ulong l;
 523
 524         memcpy((void *)&l, (void *)from, sizeof(l));
 525         return l;
 526 }
 527
 528 /* write IP *in network byteorder* */
 529 static inline void NetWriteIP(void *to, IPaddr_t ip)
 530 {
 531         memcpy(to, (void *)&ip, sizeof(ip));
 532 }
 533
 534 /* copy IP */
 535 static inline void NetCopyIP(void *to, void *from)
 536 {
 537         memcpy((void *)to, from, sizeof(IPaddr_t));
 538 }
 539
 540 /* copy ulong */
 541 static inline void NetCopyLong(ulong *to, ulong *from)
 542 {
 543         memcpy((void *)to, (void *)from, sizeof(ulong));
 544 }
 545
 546 /**
 547  * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
 548  * @addr: Pointer to a six-byte array containing the Ethernet address
 549  *
 550  * Return true if the address is all zeroes.
 551  */
 552 static inline int is_zero_ether_addr(const u8 *addr)
 553 {
 554         return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
 555 }
 556
 557 /**
 558  * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
 559  * @addr: Pointer to a six-byte array containing the Ethernet address
 560  *
 561  * Return true if the address is a multicast address.
 562  * By definition the broadcast address is also a multicast address.
 563  */
 564 static inline int is_multicast_ether_addr(const u8 *addr)
 565 {
 566         return 0x01 & addr[0];
 567 }
 568
 569 /*
 570  * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
 571  * @addr: Pointer to a six-byte array containing the Ethernet address
 572  *
 573  * Return true if the address is the broadcast address.
 574  */
 575 static inline int is_broadcast_ether_addr(const u8 *addr)
 576 {
 577         return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) ==
 578                 0xff;
 579 }
 580
 581 /*
 582  * is_valid_ether_addr - Determine if the given Ethernet address is valid
 583  * @addr: Pointer to a six-byte array containing the Ethernet address
 584  *
 585  * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
 586  * a multicast address, and is not FF:FF:FF:FF:FF:FF.
 587  *
 588  * Return true if the address is valid.
 589  */
 590 static inline int is_valid_ether_addr(const u8 *addr)
 591 {
 592         /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
 593          * explicitly check for it here. */
 594         return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
 595 }
 596
 597 /* Convert an IP address to a string */
 598 extern void ip_to_string(IPaddr_t x, char *s);
 599
 600 /* Convert a string to ip address */
 601 extern IPaddr_t string_to_ip(const char *s);
 602
 603 /* Convert a VLAN id to a string */
 604 extern void VLAN_to_string(ushort x, char *s);
 605
 606 /* Convert a string to a vlan id */
 607 extern ushort string_to_VLAN(const char *s);
 608
 609 /* read a VLAN id from an environment variable */
 610 extern ushort getenv_VLAN(char *);
 611
 612 /* copy a filename (allow for "..." notation, limit length) */
 613 extern void copy_filename(char *dst, const char *src, int size);
 614
 615 /* get a random source port */
 616 extern unsigned int random_port(void);
 617
 618 /**********************************************************************/
 619
 620 #endif /* __NET_H__ */