net/ipv4/ipconfig.c

   1 /*
   2  *  Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or
   3  *  user-supplied information to configure own IP address and routes.
   4  *
   5  *  Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
   6  *
   7  *  Derived from network configuration code in fs/nfs/nfsroot.c,
   8  *  originally Copyright (C) 1995, 1996 Gero Kuhlmann and me.
   9  *
  10  *  BOOTP rewritten to construct and analyse packets itself instead
  11  *  of misusing the IP layer. num_bugs_causing_wrong_arp_replies--;
  12  *                                           -- MJ, December 1998
  13  *
  14  *  Fixed ip_auto_config_setup calling at startup in the new "Linker Magic"
  15  *  initialization scheme.
  16  *      - Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999
  17  *
  18  *  DHCP support added.  To users this looks like a whole separate
  19  *  protocol, but we know it's just a bag on the side of BOOTP.
  20  *              -- Chip Salzenberg <chip@valinux.com>, May 2000
  21  *
  22  *  Ported DHCP support from 2.2.16 to 2.4.0-test4
  23  *              -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000
  24  *
  25  *  Merged changes from 2.2.19 into 2.4.3
  26  *              -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001
  27  *
  28  *  Multiple Nameservers in /proc/net/pnp
  29  *              --  Josef Siemes <jsiemes@web.de>, Aug 2002
  30  */
  31
  32 #include <linux/types.h>
  33 #include <linux/string.h>
  34 #include <linux/kernel.h>
  35 #include <linux/jiffies.h>
  36 #include <linux/random.h>
  37 #include <linux/init.h>
  38 #include <linux/utsname.h>
  39 #include <linux/in.h>
  40 #include <linux/if.h>
  41 #include <linux/inet.h>
  42 #include <linux/inetdevice.h>
  43 #include <linux/netdevice.h>
  44 #include <linux/if_arp.h>
  45 #include <linux/skbuff.h>
  46 #include <linux/ip.h>
  47 #include <linux/socket.h>
  48 #include <linux/route.h>
  49 #include <linux/udp.h>
  50 #include <linux/proc_fs.h>
  51 #include <linux/seq_file.h>
  52 #include <linux/major.h>
  53 #include <linux/root_dev.h>
  54 #include <linux/delay.h>
  55 #include <linux/nfs_fs.h>
  56 #include <net/net_namespace.h>
  57 #include <net/arp.h>
  58 #include <net/ip.h>
  59 #include <net/ipconfig.h>
  60 #include <net/route.h>
  61
  62 #include <asm/uaccess.h>
  63 #include <net/checksum.h>
  64 #include <asm/processor.h>
  65
  66 /* Define this to allow debugging output */
  67 #undef IPCONFIG_DEBUG
  68
  69 #ifdef IPCONFIG_DEBUG
  70 #define DBG(x) printk x
  71 #else
  72 #define DBG(x) do { } while(0)
  73 #endif
  74
  75 #if defined(CONFIG_IP_PNP_DHCP)
  76 #define IPCONFIG_DHCP
  77 #endif
  78 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
  79 #define IPCONFIG_BOOTP
  80 #endif
  81 #if defined(CONFIG_IP_PNP_RARP)
  82 #define IPCONFIG_RARP
  83 #endif
  84 #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
  85 #define IPCONFIG_DYNAMIC
  86 #endif
  87
  88 /* Define the friendly delay before and after opening net devices */
  89 #define CONF_PRE_OPEN           500     /* Before opening: 1/2 second */
  90 #define CONF_POST_OPEN          1       /* After opening: 1 second */
  91
  92 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
  93 #define CONF_OPEN_RETRIES       2       /* (Re)open devices twice */
  94 #define CONF_SEND_RETRIES       6       /* Send six requests per open */
  95 #define CONF_INTER_TIMEOUT      (HZ/2)  /* Inter-device timeout: 1/2 second */
  96 #define CONF_BASE_TIMEOUT       (HZ*2)  /* Initial timeout: 2 seconds */
  97 #define CONF_TIMEOUT_RANDOM     (HZ)    /* Maximum amount of randomization */
  98 #define CONF_TIMEOUT_MULT       *7/4    /* Rate of timeout growth */
  99 #define CONF_TIMEOUT_MAX        (HZ*30) /* Maximum allowed timeout */
 100 #define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
 101                                            - '3' from resolv.h */
 102
 103 #define NONE __constant_htonl(INADDR_NONE)
 104 #define ANY __constant_htonl(INADDR_ANY)
 105
 106 /*
 107  * Public IP configuration
 108  */
 109
 110 /* This is used by platforms which might be able to set the ipconfig
 111  * variables using firmware environment vars.  If this is set, it will
 112  * ignore such firmware variables.
 113  */
 114 int ic_set_manually __initdata = 0;             /* IPconfig parameters set manually */
 115
 116 static int ic_enable __initdata = 0;            /* IP config enabled? */
 117
 118 /* Protocol choice */
 119 int ic_proto_enabled __initdata = 0
 120 #ifdef IPCONFIG_BOOTP
 121                         | IC_BOOTP
 122 #endif
 123 #ifdef CONFIG_IP_PNP_DHCP
 124                         | IC_USE_DHCP
 125 #endif
 126 #ifdef IPCONFIG_RARP
 127                         | IC_RARP
 128 #endif
 129                         ;
 130
 131 static int ic_host_name_set __initdata = 0;     /* Host name set by us? */
 132
 133 __be32 ic_myaddr = NONE;                /* My IP address */
 134 static __be32 ic_netmask = NONE;        /* Netmask for local subnet */
 135 __be32 ic_gateway = NONE;       /* Gateway IP address */
 136
 137 __be32 ic_servaddr = NONE;      /* Boot server IP address */
 138
 139 __be32 root_server_addr = NONE; /* Address of NFS server */
 140 u8 root_server_path[256] = { 0, };      /* Path to mount as root */
 141
 142 /* vendor class identifier */
 143 static char vendor_class_identifier[253] __initdata;
 144
 145 /* Persistent data: */
 146
 147 static int ic_proto_used;                       /* Protocol used, if any */
 148 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
 149 static u8 ic_domain[64];                /* DNS (not NIS) domain name */
 150
 151 /*
 152  * Private state.
 153  */
 154
 155 /* Name of user-selected boot device */
 156 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
 157
 158 /* Protocols supported by available interfaces */
 159 static int ic_proto_have_if __initdata = 0;
 160
 161 #ifdef IPCONFIG_DYNAMIC
 162 static DEFINE_SPINLOCK(ic_recv_lock);
 163 static volatile int ic_got_reply __initdata = 0;    /* Proto(s) that replied */
 164 #endif
 165 #ifdef IPCONFIG_DHCP
 166 static int ic_dhcp_msgtype __initdata = 0;      /* DHCP msg type received */
 167 #endif
 168
 169
 170 /*
 171  *      Network devices
 172  */
 173
 174 struct ic_device {
 175         struct ic_device *next;
 176         struct net_device *dev;
 177         unsigned short flags;
 178         short able;
 179         __be32 xid;
 180 };
 181
 182 static struct ic_device *ic_first_dev __initdata = NULL;/* List of open device */
 183 static struct net_device *ic_dev __initdata = NULL;     /* Selected device */
 184
 185 static int __init ic_open_devs(void)
 186 {
 187         struct ic_device *d, **last;
 188         struct net_device *dev;
 189         unsigned short oflags;
 190
 191         last = &ic_first_dev;
 192         rtnl_lock();
 193
 194         /* bring loopback device up first */
 195         for_each_netdev(&init_net, dev) {
 196                 if (!(dev->flags & IFF_LOOPBACK))
 197                         continue;
 198                 if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
 199                         printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
 200         }
 201
 202         for_each_netdev(&init_net, dev) {
 203                 if (dev->flags & IFF_LOOPBACK)
 204                         continue;
 205                 if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
 206                     (!(dev->flags & IFF_LOOPBACK) &&
 207                      (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
 208                      strncmp(dev->name, "dummy", 5))) {
 209                         int able = 0;
 210                         if (dev->mtu >= 364)
 211                                 able |= IC_BOOTP;
 212                         else
 213                                 printk(KERN_WARNING "DHCP/BOOTP: Ignoring device %s, MTU %d too small", dev->name, dev->mtu);
 214                         if (!(dev->flags & IFF_NOARP))
 215                                 able |= IC_RARP;
 216                         able &= ic_proto_enabled;
 217                         if (ic_proto_enabled && !able)
 218                                 continue;
 219                         oflags = dev->flags;
 220                         if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
 221                                 printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
 222                                 continue;
 223                         }
 224                         if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
 225                                 rtnl_unlock();
 226                                 return -1;
 227                         }
 228                         d->dev = dev;
 229                         *last = d;
 230                         last = &d->next;
 231                         d->flags = oflags;
 232                         d->able = able;
 233                         if (able & IC_BOOTP)
 234                                 get_random_bytes(&d->xid, sizeof(__be32));
 235                         else
 236                                 d->xid = 0;
 237                         ic_proto_have_if |= able;
 238                         DBG(("IP-Config: %s UP (able=%d, xid=%08x)\n",
 239                                 dev->name, able, d->xid));
 240                 }
 241         }
 242         rtnl_unlock();
 243
 244         *last = NULL;
 245
 246         if (!ic_first_dev) {
 247                 if (user_dev_name[0])
 248                         printk(KERN_ERR "IP-Config: Device `%s' not found.\n", user_dev_name);
 249                 else
 250                         printk(KERN_ERR "IP-Config: No network devices available.\n");
 251                 return -1;
 252         }
 253         return 0;
 254 }
 255
 256 static void __init ic_close_devs(void)
 257 {
 258         struct ic_device *d, *next;
 259         struct net_device *dev;
 260
 261         rtnl_lock();
 262         next = ic_first_dev;
 263         while ((d = next)) {
 264                 next = d->next;
 265                 dev = d->dev;
 266                 if (dev != ic_dev) {
 267                         DBG(("IP-Config: Downing %s\n", dev->name));
 268                         dev_change_flags(dev, d->flags);
 269                 }
 270                 kfree(d);
 271         }
 272         rtnl_unlock();
 273 }
 274
 275 /*
 276  *      Interface to various network functions.
 277  */
 278
 279 static inline void
 280 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
 281 {
 282         sin->sin_family = AF_INET;
 283         sin->sin_addr.s_addr = addr;
 284         sin->sin_port = port;
 285 }
 286
 287 static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
 288 {
 289         int res;
 290
 291         mm_segment_t oldfs = get_fs();
 292         set_fs(get_ds());
 293         res = devinet_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
 294         set_fs(oldfs);
 295         return res;
 296 }
 297
 298 static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg)
 299 {
 300         int res;
 301
 302         mm_segment_t oldfs = get_fs();
 303         set_fs(get_ds());
 304         res = ip_rt_ioctl(&init_net, cmd, (void __user *) arg);
 305         set_fs(oldfs);
 306         return res;
 307 }
 308
 309 /*
 310  *      Set up interface addresses and routes.
 311  */
 312
 313 static int __init ic_setup_if(void)
 314 {
 315         struct ifreq ir;
 316         struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
 317         int err;
 318
 319         memset(&ir, 0, sizeof(ir));
 320         strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->name);
 321         set_sockaddr(sin, ic_myaddr, 0);
 322         if ((err = ic_dev_ioctl(SIOCSIFADDR, &ir)) < 0) {
 323                 printk(KERN_ERR "IP-Config: Unable to set interface address (%d).\n", err);
 324                 return -1;
 325         }
 326         set_sockaddr(sin, ic_netmask, 0);
 327         if ((err = ic_dev_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
 328                 printk(KERN_ERR "IP-Config: Unable to set interface netmask (%d).\n", err);
 329                 return -1;
 330         }
 331         set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
 332         if ((err = ic_dev_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
 333                 printk(KERN_ERR "IP-Config: Unable to set interface broadcast address (%d).\n", err);
 334                 return -1;
 335         }
 336         return 0;
 337 }
 338
 339 static int __init ic_setup_routes(void)
 340 {
 341         /* No need to setup device routes, only the default route... */
 342
 343         if (ic_gateway != NONE) {
 344                 struct rtentry rm;
 345                 int err;
 346
 347                 memset(&rm, 0, sizeof(rm));
 348                 if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
 349                         printk(KERN_ERR "IP-Config: Gateway not on directly connected network.\n");
 350                         return -1;
 351                 }
 352                 set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
 353                 set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
 354                 set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
 355                 rm.rt_flags = RTF_UP | RTF_GATEWAY;
 356                 if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) {
 357                         printk(KERN_ERR "IP-Config: Cannot add default route (%d).\n", err);
 358                         return -1;
 359                 }
 360         }
 361
 362         return 0;
 363 }
 364
 365 /*
 366  *      Fill in default values for all missing parameters.
 367  */
 368
 369 static int __init ic_defaults(void)
 370 {
 371         /*
 372          *      At this point we have no userspace running so need not
 373          *      claim locks on system_utsname
 374          */
 375
 376         if (!ic_host_name_set)
 377                 sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
 378
 379         if (root_server_addr == NONE)
 380                 root_server_addr = ic_servaddr;
 381
 382         if (ic_netmask == NONE) {
 383                 if (IN_CLASSA(ntohl(ic_myaddr)))
 384                         ic_netmask = htonl(IN_CLASSA_NET);
 385                 else if (IN_CLASSB(ntohl(ic_myaddr)))
 386                         ic_netmask = htonl(IN_CLASSB_NET);
 387                 else if (IN_CLASSC(ntohl(ic_myaddr)))
 388                         ic_netmask = htonl(IN_CLASSC_NET);
 389                 else {
 390                         printk(KERN_ERR "IP-Config: Unable to guess netmask for address %pI4\n",
 391                                 &ic_myaddr);
 392                         return -1;
 393                 }
 394                 printk("IP-Config: Guessing netmask %pI4\n", &ic_netmask);
 395         }
 396
 397         return 0;
 398 }
 399
 400 /*
 401  *      RARP support.
 402  */
 403
 404 #ifdef IPCONFIG_RARP
 405
 406 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
 407
 408 static struct packet_type rarp_packet_type __initdata = {
 409         .type = __constant_htons(ETH_P_RARP),
 410         .func = ic_rarp_recv,
 411 };
 412
 413 static inline void __init ic_rarp_init(void)
 414 {
 415         dev_add_pack(&rarp_packet_type);
 416 }
 417
 418 static inline void __init ic_rarp_cleanup(void)
 419 {
 420         dev_remove_pack(&rarp_packet_type);
 421 }
 422
 423 /*
 424  *  Process received RARP packet.
 425  */
 426 static int __init
 427 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 428 {
 429         struct arphdr *rarp;
 430         unsigned char *rarp_ptr;
 431         __be32 sip, tip;
 432         unsigned char *sha, *tha;               /* s for "source", t for "target" */
 433         struct ic_device *d;
 434
 435         if (!net_eq(dev_net(dev), &init_net))
 436                 goto drop;
 437
 438         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
 439                 return NET_RX_DROP;
 440
 441         if (!pskb_may_pull(skb, sizeof(struct arphdr)))
 442                 goto drop;
 443
 444         /* Basic sanity checks can be done without the lock.  */
 445         rarp = (struct arphdr *)skb_transport_header(skb);
 446
 447         /* If this test doesn't pass, it's not IP, or we should
 448          * ignore it anyway.
 449          */
 450         if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
 451                 goto drop;
 452
 453         /* If it's not a RARP reply, delete it. */
 454         if (rarp->ar_op != htons(ARPOP_RREPLY))
 455                 goto drop;
 456
 457         /* If it's not Ethernet, delete it. */
 458         if (rarp->ar_pro != htons(ETH_P_IP))
 459                 goto drop;
 460
 461         if (!pskb_may_pull(skb, arp_hdr_len(dev)))
 462                 goto drop;
 463
 464         /* OK, it is all there and looks valid, process... */
 465         rarp = (struct arphdr *)skb_transport_header(skb);
 466         rarp_ptr = (unsigned char *) (rarp + 1);
 467
 468         /* One reply at a time, please. */
 469         spin_lock(&ic_recv_lock);
 470
 471         /* If we already have a reply, just drop the packet */
 472         if (ic_got_reply)
 473                 goto drop_unlock;
 474
 475         /* Find the ic_device that the packet arrived on */
 476         d = ic_first_dev;
 477         while (d && d->dev != dev)
 478                 d = d->next;
 479         if (!d)
 480                 goto drop_unlock;       /* should never happen */
 481
 482         /* Extract variable-width fields */
 483         sha = rarp_ptr;
 484         rarp_ptr += dev->addr_len;
 485         memcpy(&sip, rarp_ptr, 4);
 486         rarp_ptr += 4;
 487         tha = rarp_ptr;
 488         rarp_ptr += dev->addr_len;
 489         memcpy(&tip, rarp_ptr, 4);
 490
 491         /* Discard packets which are not meant for us. */
 492         if (memcmp(tha, dev->dev_addr, dev->addr_len))
 493                 goto drop_unlock;
 494
 495         /* Discard packets which are not from specified server. */
 496         if (ic_servaddr != NONE && ic_servaddr != sip)
 497                 goto drop_unlock;
 498
 499         /* We have a winner! */
 500         ic_dev = dev;
 501         if (ic_myaddr == NONE)
 502                 ic_myaddr = tip;
 503         ic_servaddr = sip;
 504         ic_got_reply = IC_RARP;
 505
 506 drop_unlock:
 507         /* Show's over.  Nothing to see here.  */
 508         spin_unlock(&ic_recv_lock);
 509
 510 drop:
 511         /* Throw the packet out. */
 512         kfree_skb(skb);
 513         return 0;
 514 }
 515
 516
 517 /*
 518  *  Send RARP request packet over a single interface.
 519  */
 520 static void __init ic_rarp_send_if(struct ic_device *d)
 521 {
 522         struct net_device *dev = d->dev;
 523         arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
 524                  dev->dev_addr, dev->dev_addr);
 525 }
 526 #endif
 527
 528 /*
 529  *      DHCP/BOOTP support.
 530  */
 531
 532 #ifdef IPCONFIG_BOOTP
 533
 534 struct bootp_pkt {              /* BOOTP packet format */
 535         struct iphdr iph;       /* IP header */
 536         struct udphdr udph;     /* UDP header */
 537         u8 op;                  /* 1=request, 2=reply */
 538         u8 htype;               /* HW address type */
 539         u8 hlen;                /* HW address length */
 540         u8 hops;                /* Used only by gateways */
 541         __be32 xid;             /* Transaction ID */
 542         __be16 secs;            /* Seconds since we started */
 543         __be16 flags;           /* Just what it says */
 544         __be32 client_ip;               /* Client's IP address if known */
 545         __be32 your_ip;         /* Assigned IP address */
 546         __be32 server_ip;               /* (Next, e.g. NFS) Server's IP address */
 547         __be32 relay_ip;                /* IP address of BOOTP relay */
 548         u8 hw_addr[16];         /* Client's HW address */
 549         u8 serv_name[64];       /* Server host name */
 550         u8 boot_file[128];      /* Name of boot file */
 551         u8 exten[312];          /* DHCP options / BOOTP vendor extensions */
 552 };
 553
 554 /* packet ops */
 555 #define BOOTP_REQUEST   1
 556 #define BOOTP_REPLY     2
 557
 558 /* DHCP message types */
 559 #define DHCPDISCOVER    1
 560 #define DHCPOFFER       2
 561 #define DHCPREQUEST     3
 562 #define DHCPDECLINE     4
 563 #define DHCPACK         5
 564 #define DHCPNAK         6
 565 #define DHCPRELEASE     7
 566 #define DHCPINFORM      8
 567
 568 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
 569
 570 static struct packet_type bootp_packet_type __initdata = {
 571         .type = __constant_htons(ETH_P_IP),
 572         .func = ic_bootp_recv,
 573 };
 574
 575
 576 /*
 577  *  Initialize DHCP/BOOTP extension fields in the request.
 578  */
 579
 580 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
 581
 582 #ifdef IPCONFIG_DHCP
 583
 584 static void __init
 585 ic_dhcp_init_options(u8 *options)
 586 {
 587         u8 mt = ((ic_servaddr == NONE)
 588                  ? DHCPDISCOVER : DHCPREQUEST);
 589         u8 *e = options;
 590         int len;
 591
 592 #ifdef IPCONFIG_DEBUG
 593         printk("DHCP: Sending message type %d\n", mt);
 594 #endif
 595
 596         memcpy(e, ic_bootp_cookie, 4);  /* RFC1048 Magic Cookie */
 597         e += 4;
 598
 599         *e++ = 53;              /* DHCP message type */
 600         *e++ = 1;
 601         *e++ = mt;
 602
 603         if (mt == DHCPREQUEST) {
 604                 *e++ = 54;      /* Server ID (IP address) */
 605                 *e++ = 4;
 606                 memcpy(e, &ic_servaddr, 4);
 607                 e += 4;
 608
 609                 *e++ = 50;      /* Requested IP address */
 610                 *e++ = 4;
 611                 memcpy(e, &ic_myaddr, 4);
 612                 e += 4;
 613         }
 614
 615         /* always? */
 616         {
 617                 static const u8 ic_req_params[] = {
 618                         1,      /* Subnet mask */
 619                         3,      /* Default gateway */
 620                         6,      /* DNS server */
 621                         12,     /* Host name */
 622                         15,     /* Domain name */
 623                         17,     /* Boot path */
 624                         40,     /* NIS domain name */
 625                 };
 626
 627                 *e++ = 55;      /* Parameter request list */
 628                 *e++ = sizeof(ic_req_params);
 629                 memcpy(e, ic_req_params, sizeof(ic_req_params));
 630                 e += sizeof(ic_req_params);
 631
 632                 if (*vendor_class_identifier) {
 633                         printk(KERN_INFO "DHCP: sending class identifier \"%s\"\n",
 634                                vendor_class_identifier);
 635                         *e++ = 60;      /* Class-identifier */
 636                         len = strlen(vendor_class_identifier);
 637                         *e++ = len;
 638                         memcpy(e, vendor_class_identifier, len);
 639                         e += len;
 640                 }
 641         }
 642
 643         *e++ = 255;     /* End of the list */
 644 }
 645
 646 #endif /* IPCONFIG_DHCP */
 647
 648 static void __init ic_bootp_init_ext(u8 *e)
 649 {
 650         memcpy(e, ic_bootp_cookie, 4);  /* RFC1048 Magic Cookie */
 651         e += 4;
 652         *e++ = 1;               /* Subnet mask request */
 653         *e++ = 4;
 654         e += 4;
 655         *e++ = 3;               /* Default gateway request */
 656         *e++ = 4;
 657         e += 4;
 658         *e++ = 5;               /* Name server request */
 659         *e++ = 8;
 660         e += 8;
 661         *e++ = 12;              /* Host name request */
 662         *e++ = 32;
 663         e += 32;
 664         *e++ = 40;              /* NIS Domain name request */
 665         *e++ = 32;
 666         e += 32;
 667         *e++ = 17;              /* Boot path */
 668         *e++ = 40;
 669         e += 40;
 670
 671         *e++ = 57;              /* set extension buffer size for reply */
 672         *e++ = 2;
 673         *e++ = 1;               /* 128+236+8+20+14, see dhcpd sources */
 674         *e++ = 150;
 675
 676         *e++ = 255;             /* End of the list */
 677 }
 678
 679
 680 /*
 681  *  Initialize the DHCP/BOOTP mechanism.
 682  */
 683 static inline void __init ic_bootp_init(void)
 684 {
 685         int i;
 686
 687         for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
 688                 ic_nameservers[i] = NONE;
 689
 690         dev_add_pack(&bootp_packet_type);
 691 }
 692
 693
 694 /*
 695  *  DHCP/BOOTP cleanup.
 696  */
 697 static inline void __init ic_bootp_cleanup(void)
 698 {
 699         dev_remove_pack(&bootp_packet_type);
 700 }
 701
 702
 703 /*
 704  *  Send DHCP/BOOTP request to single interface.
 705  */
 706 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
 707 {
 708         struct net_device *dev = d->dev;
 709         struct sk_buff *skb;
 710         struct bootp_pkt *b;
 711         struct iphdr *h;
 712
 713         /* Allocate packet */
 714         skb = alloc_skb(sizeof(struct bootp_pkt) + LL_ALLOCATED_SPACE(dev) + 15,
 715                         GFP_KERNEL);
 716         if (!skb)
 717                 return;
 718         skb_reserve(skb, LL_RESERVED_SPACE(dev));
 719         b = (struct bootp_pkt *) skb_put(skb, sizeof(struct bootp_pkt));
 720         memset(b, 0, sizeof(struct bootp_pkt));
 721
 722         /* Construct IP header */
 723         skb_reset_network_header(skb);
 724         h = ip_hdr(skb);
 725         h->version = 4;
 726         h->ihl = 5;
 727         h->tot_len = htons(sizeof(struct bootp_pkt));
 728         h->frag_off = htons(IP_DF);
 729         h->ttl = 64;
 730         h->protocol = IPPROTO_UDP;
 731         h->daddr = htonl(INADDR_BROADCAST);
 732         h->check = ip_fast_csum((unsigned char *) h, h->ihl);
 733
 734         /* Construct UDP header */
 735         b->udph.source = htons(68);
 736         b->udph.dest = htons(67);
 737         b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
 738         /* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
 739
 740         /* Construct DHCP/BOOTP header */
 741         b->op = BOOTP_REQUEST;
 742         if (dev->type < 256) /* check for false types */
 743                 b->htype = dev->type;
 744         else if (dev->type == ARPHRD_IEEE802_TR) /* fix for token ring */
 745                 b->htype = ARPHRD_IEEE802;
 746         else if (dev->type == ARPHRD_FDDI)
 747                 b->htype = ARPHRD_ETHER;
 748         else {
 749                 printk("Unknown ARP type 0x%04x for device %s\n", dev->type, dev->name);
 750                 b->htype = dev->type; /* can cause undefined behavior */
 751         }
 752
 753         /* server_ip and your_ip address are both already zero per RFC2131 */
 754         b->hlen = dev->addr_len;
 755         memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
 756         b->secs = htons(jiffies_diff / HZ);
 757         b->xid = d->xid;
 758
 759         /* add DHCP options or BOOTP extensions */
 760 #ifdef IPCONFIG_DHCP
 761         if (ic_proto_enabled & IC_USE_DHCP)
 762                 ic_dhcp_init_options(b->exten);
 763         else
 764 #endif
 765                 ic_bootp_init_ext(b->exten);
 766
 767         /* Chain packet down the line... */
 768         skb->dev = dev;
 769         skb->protocol = htons(ETH_P_IP);
 770         if (dev_hard_header(skb, dev, ntohs(skb->protocol),
 771                             dev->broadcast, dev->dev_addr, skb->len) < 0 ||
 772             dev_queue_xmit(skb) < 0)
 773                 printk("E");
 774 }
 775
 776
 777 /*
 778  *  Copy BOOTP-supplied string if not already set.
 779  */
 780 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
 781 {
 782         if (!len)
 783                 return 0;
 784         if (len > max-1)
 785                 len = max-1;
 786         memcpy(dest, src, len);
 787         dest[len] = '\0';
 788         return 1;
 789 }
 790
 791
 792 /*
 793  *  Process BOOTP extensions.
 794  */
 795 static void __init ic_do_bootp_ext(u8 *ext)
 796 {
 797        u8 servers;
 798        int i;
 799
 800 #ifdef IPCONFIG_DEBUG
 801         u8 *c;
 802
 803         printk("DHCP/BOOTP: Got extension %d:",*ext);
 804         for (c=ext+2; c<ext+2+ext[1]; c++)
 805                 printk(" %02x", *c);
 806         printk("\n");
 807 #endif
 808
 809         switch (*ext++) {
 810                 case 1:         /* Subnet mask */
 811                         if (ic_netmask == NONE)
 812                                 memcpy(&ic_netmask, ext+1, 4);
 813                         break;
 814                 case 3:         /* Default gateway */
 815                         if (ic_gateway == NONE)
 816                                 memcpy(&ic_gateway, ext+1, 4);
 817                         break;
 818                 case 6:         /* DNS server */
 819                         servers= *ext/4;
 820                         if (servers > CONF_NAMESERVERS_MAX)
 821                                 servers = CONF_NAMESERVERS_MAX;
 822                         for (i = 0; i < servers; i++) {
 823                                 if (ic_nameservers[i] == NONE)
 824                                         memcpy(&ic_nameservers[i], ext+1+4*i, 4);
 825                         }
 826                         break;
 827                 case 12:        /* Host name */
 828                         ic_bootp_string(utsname()->nodename, ext+1, *ext, __NEW_UTS_LEN);
 829                         ic_host_name_set = 1;
 830                         break;
 831                 case 15:        /* Domain name (DNS) */
 832                         ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
 833                         break;
 834                 case 17:        /* Root path */
 835                         if (!root_server_path[0])
 836                                 ic_bootp_string(root_server_path, ext+1, *ext, sizeof(root_server_path));
 837                         break;
 838                 case 40:        /* NIS Domain name (_not_ DNS) */
 839                         ic_bootp_string(utsname()->domainname, ext+1, *ext, __NEW_UTS_LEN);
 840                         break;
 841         }
 842 }
 843
 844
 845 /*
 846  *  Receive BOOTP reply.
 847  */
 848 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 849 {
 850         struct bootp_pkt *b;
 851         struct iphdr *h;
 852         struct ic_device *d;
 853         int len, ext_len;
 854
 855         if (!net_eq(dev_net(dev), &init_net))
 856                 goto drop;
 857
 858         /* Perform verifications before taking the lock.  */
 859         if (skb->pkt_type == PACKET_OTHERHOST)
 860                 goto drop;
 861
 862         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
 863                 return NET_RX_DROP;
 864
 865         if (!pskb_may_pull(skb,
 866                            sizeof(struct iphdr) +
 867                            sizeof(struct udphdr)))
 868                 goto drop;
 869
 870         b = (struct bootp_pkt *)skb_network_header(skb);
 871         h = &b->iph;
 872
 873         if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
 874                 goto drop;
 875
 876         /* Fragments are not supported */
 877         if (h->frag_off & htons(IP_OFFSET | IP_MF)) {
 878                 if (net_ratelimit())
 879                         printk(KERN_ERR "DHCP/BOOTP: Ignoring fragmented "
 880                                "reply.\n");
 881                 goto drop;
 882         }
 883
 884         if (skb->len < ntohs(h->tot_len))
 885                 goto drop;
 886
 887         if (ip_fast_csum((char *) h, h->ihl))
 888                 goto drop;
 889
 890         if (b->udph.source != htons(67) || b->udph.dest != htons(68))
 891                 goto drop;
 892
 893         if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
 894                 goto drop;
 895
 896         len = ntohs(b->udph.len) - sizeof(struct udphdr);
 897         ext_len = len - (sizeof(*b) -
 898                          sizeof(struct iphdr) -
 899                          sizeof(struct udphdr) -
 900                          sizeof(b->exten));
 901         if (ext_len < 0)
 902                 goto drop;
 903
 904         /* Ok the front looks good, make sure we can get at the rest.  */
 905         if (!pskb_may_pull(skb, skb->len))
 906                 goto drop;
 907
 908         b = (struct bootp_pkt *)skb_network_header(skb);
 909         h = &b->iph;
 910
 911         /* One reply at a time, please. */
 912         spin_lock(&ic_recv_lock);
 913
 914         /* If we already have a reply, just drop the packet */
 915         if (ic_got_reply)
 916                 goto drop_unlock;
 917
 918         /* Find the ic_device that the packet arrived on */
 919         d = ic_first_dev;
 920         while (d && d->dev != dev)
 921                 d = d->next;
 922         if (!d)
 923                 goto drop_unlock;  /* should never happen */
 924
 925         /* Is it a reply to our BOOTP request? */
 926         if (b->op != BOOTP_REPLY ||
 927             b->xid != d->xid) {
 928                 if (net_ratelimit())
 929                         printk(KERN_ERR "DHCP/BOOTP: Reply not for us, "
 930                                "op[%x] xid[%x]\n",
 931                                b->op, b->xid);
 932                 goto drop_unlock;
 933         }
 934
 935         /* Parse extensions */
 936         if (ext_len >= 4 &&
 937             !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
 938                 u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
 939                 u8 *ext;
 940
 941 #ifdef IPCONFIG_DHCP
 942                 if (ic_proto_enabled & IC_USE_DHCP) {
 943                         __be32 server_id = NONE;
 944                         int mt = 0;
 945
 946                         ext = &b->exten[4];
 947                         while (ext < end && *ext != 0xff) {
 948                                 u8 *opt = ext++;
 949                                 if (*opt == 0)  /* Padding */
 950                                         continue;
 951                                 ext += *ext + 1;
 952                                 if (ext >= end)
 953                                         break;
 954                                 switch (*opt) {
 955                                 case 53:        /* Message type */
 956                                         if (opt[1])
 957                                                 mt = opt[2];
 958                                         break;
 959                                 case 54:        /* Server ID (IP address) */
 960                                         if (opt[1] >= 4)
 961                                                 memcpy(&server_id, opt + 2, 4);
 962                                         break;
 963                                 }
 964                         }
 965
 966 #ifdef IPCONFIG_DEBUG
 967                         printk("DHCP: Got message type %d\n", mt);
 968 #endif
 969
 970                         switch (mt) {
 971                         case DHCPOFFER:
 972                                 /* While in the process of accepting one offer,
 973                                  * ignore all others.
 974                                  */
 975                                 if (ic_myaddr != NONE)
 976                                         goto drop_unlock;
 977
 978                                 /* Let's accept that offer. */
 979                                 ic_myaddr = b->your_ip;
 980                                 ic_servaddr = server_id;
 981 #ifdef IPCONFIG_DEBUG
 982                                 printk("DHCP: Offered address %pI4 by server %pI4\n",
 983                                        &ic_myaddr, &ic_servaddr);
 984 #endif
 985                                 /* The DHCP indicated server address takes
 986                                  * precedence over the bootp header one if
 987                                  * they are different.
 988                                  */
 989                                 if ((server_id != NONE) &&
 990                                     (b->server_ip != server_id))
 991                                         b->server_ip = ic_servaddr;
 992                                 break;
 993
 994                         case DHCPACK:
 995                                 if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
 996                                         goto drop_unlock;
 997
 998                                 /* Yeah! */
 999                                 break;
1000
1001                         default:
1002                                 /* Urque.  Forget it*/
1003                                 ic_myaddr = NONE;
1004                                 ic_servaddr = NONE;
1005                                 goto drop_unlock;
1006                         }
1007
1008                         ic_dhcp_msgtype = mt;
1009
1010                 }
1011 #endif /* IPCONFIG_DHCP */
1012
1013                 ext = &b->exten[4];
1014                 while (ext < end && *ext != 0xff) {
1015                         u8 *opt = ext++;
1016                         if (*opt == 0)  /* Padding */
1017                                 continue;
1018                         ext += *ext + 1;
1019                         if (ext < end)
1020                                 ic_do_bootp_ext(opt);
1021                 }
1022         }
1023
1024         /* We have a winner! */
1025         ic_dev = dev;
1026         ic_myaddr = b->your_ip;
1027         ic_servaddr = b->server_ip;
1028         if (ic_gateway == NONE && b->relay_ip)
1029                 ic_gateway = b->relay_ip;
1030         if (ic_nameservers[0] == NONE)
1031                 ic_nameservers[0] = ic_servaddr;
1032         ic_got_reply = IC_BOOTP;
1033
1034 drop_unlock:
1035         /* Show's over.  Nothing to see here.  */
1036         spin_unlock(&ic_recv_lock);
1037
1038 drop:
1039         /* Throw the packet out. */
1040         kfree_skb(skb);
1041
1042         return 0;
1043 }
1044
1045
1046 #endif
1047
1048
1049 /*
1050  *      Dynamic IP configuration -- DHCP, BOOTP, RARP.
1051  */
1052
1053 #ifdef IPCONFIG_DYNAMIC
1054
1055 static int __init ic_dynamic(void)
1056 {
1057         int retries;
1058         struct ic_device *d;
1059         unsigned long start_jiffies, timeout, jiff;
1060         int do_bootp = ic_proto_have_if & IC_BOOTP;
1061         int do_rarp = ic_proto_have_if & IC_RARP;
1062
1063         /*
1064          * If none of DHCP/BOOTP/RARP was selected, return with an error.
1065          * This routine gets only called when some pieces of information
1066          * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1067          */
1068         if (!ic_proto_enabled) {
1069                 printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
1070                 return -1;
1071         }
1072
1073 #ifdef IPCONFIG_BOOTP
1074         if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1075                 printk(KERN_ERR "DHCP/BOOTP: No suitable device found.\n");
1076 #endif
1077 #ifdef IPCONFIG_RARP
1078         if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1079                 printk(KERN_ERR "RARP: No suitable device found.\n");
1080 #endif
1081
1082         if (!ic_proto_have_if)
1083                 /* Error message already printed */
1084                 return -1;
1085
1086         /*
1087          * Setup protocols
1088          */
1089 #ifdef IPCONFIG_BOOTP
1090         if (do_bootp)
1091                 ic_bootp_init();
1092 #endif
1093 #ifdef IPCONFIG_RARP
1094         if (do_rarp)
1095                 ic_rarp_init();
1096 #endif
1097
1098         /*
1099          * Send requests and wait, until we get an answer. This loop
1100          * seems to be a terrible waste of CPU time, but actually there is
1101          * only one process running at all, so we don't need to use any
1102          * scheduler functions.
1103          * [Actually we could now, but the nothing else running note still
1104          *  applies.. - AC]
1105          */
1106         printk(KERN_NOTICE "Sending %s%s%s requests .",
1107                do_bootp
1108                 ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1109                (do_bootp && do_rarp) ? " and " : "",
1110                do_rarp ? "RARP" : "");
1111
1112         start_jiffies = jiffies;
1113         d = ic_first_dev;
1114         retries = CONF_SEND_RETRIES;
1115         get_random_bytes(&timeout, sizeof(timeout));
1116         timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned) CONF_TIMEOUT_RANDOM);
1117         for (;;) {
1118 #ifdef IPCONFIG_BOOTP
1119                 if (do_bootp && (d->able & IC_BOOTP))
1120                         ic_bootp_send_if(d, jiffies - start_jiffies);
1121 #endif
1122 #ifdef IPCONFIG_RARP
1123                 if (do_rarp && (d->able & IC_RARP))
1124                         ic_rarp_send_if(d);
1125 #endif
1126
1127                 jiff = jiffies + (d->next ? CONF_INTER_TIMEOUT : timeout);
1128                 while (time_before(jiffies, jiff) && !ic_got_reply)
1129                         schedule_timeout_uninterruptible(1);
1130 #ifdef IPCONFIG_DHCP
1131                 /* DHCP isn't done until we get a DHCPACK. */
1132                 if ((ic_got_reply & IC_BOOTP)
1133                     && (ic_proto_enabled & IC_USE_DHCP)
1134                     && ic_dhcp_msgtype != DHCPACK)
1135                 {
1136                         ic_got_reply = 0;
1137                         printk(",");
1138                         continue;
1139                 }
1140 #endif /* IPCONFIG_DHCP */
1141
1142                 if (ic_got_reply) {
1143                         printk(" OK\n");
1144                         break;
1145                 }
1146
1147                 if ((d = d->next))
1148                         continue;
1149
1150                 if (! --retries) {
1151                         printk(" timed out!\n");
1152                         break;
1153                 }
1154
1155                 d = ic_first_dev;
1156
1157                 timeout = timeout CONF_TIMEOUT_MULT;
1158                 if (timeout > CONF_TIMEOUT_MAX)
1159                         timeout = CONF_TIMEOUT_MAX;
1160
1161                 printk(".");
1162         }
1163
1164 #ifdef IPCONFIG_BOOTP
1165         if (do_bootp)
1166                 ic_bootp_cleanup();
1167 #endif
1168 #ifdef IPCONFIG_RARP
1169         if (do_rarp)
1170                 ic_rarp_cleanup();
1171 #endif
1172
1173         if (!ic_got_reply) {
1174                 ic_myaddr = NONE;
1175                 return -1;
1176         }
1177
1178         printk("IP-Config: Got %s answer from %pI4, ",
1179                 ((ic_got_reply & IC_RARP) ? "RARP"
1180                  : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1181                 &ic_servaddr);
1182         printk("my address is %pI4\n", &ic_myaddr);
1183
1184         return 0;
1185 }
1186
1187 #endif /* IPCONFIG_DYNAMIC */
1188
1189 #ifdef CONFIG_PROC_FS
1190
1191 static int pnp_seq_show(struct seq_file *seq, void *v)
1192 {
1193         int i;
1194
1195         if (ic_proto_used & IC_PROTO)
1196                 seq_printf(seq, "#PROTO: %s\n",
1197                            (ic_proto_used & IC_RARP) ? "RARP"
1198                            : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1199         else
1200                 seq_puts(seq, "#MANUAL\n");
1201
1202         if (ic_domain[0])
1203                 seq_printf(seq,
1204                            "domain %s\n", ic_domain);
1205         for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1206                 if (ic_nameservers[i] != NONE)
1207                         seq_printf(seq, "nameserver %pI4\n",
1208                                    &ic_nameservers[i]);
1209         }
1210         if (ic_servaddr != NONE)
1211                 seq_printf(seq, "bootserver %pI4\n",
1212                            &ic_servaddr);
1213         return 0;
1214 }
1215
1216 static int pnp_seq_open(struct inode *indoe, struct file *file)
1217 {
1218         return single_open(file, pnp_seq_show, NULL);
1219 }
1220
1221 static const struct file_operations pnp_seq_fops = {
1222         .owner          = THIS_MODULE,
1223         .open           = pnp_seq_open,
1224         .read           = seq_read,
1225         .llseek         = seq_lseek,
1226         .release        = single_release,
1227 };
1228 #endif /* CONFIG_PROC_FS */
1229
1230 /*
1231  *  Extract IP address from the parameter string if needed. Note that we
1232  *  need to have root_server_addr set _before_ IPConfig gets called as it
1233  *  can override it.
1234  */
1235 __be32 __init root_nfs_parse_addr(char *name)
1236 {
1237         __be32 addr;
1238         int octets = 0;
1239         char *cp, *cq;
1240
1241         cp = cq = name;
1242         while (octets < 4) {
1243                 while (*cp >= '0' && *cp <= '9')
1244                         cp++;
1245                 if (cp == cq || cp - cq > 3)
1246                         break;
1247                 if (*cp == '.' || octets == 3)
1248                         octets++;
1249                 if (octets < 4)
1250                         cp++;
1251                 cq = cp;
1252         }
1253         if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1254                 if (*cp == ':')
1255                         *cp++ = '\0';
1256                 addr = in_aton(name);
1257                 memmove(name, cp, strlen(cp) + 1);
1258         } else
1259                 addr = NONE;
1260
1261         return addr;
1262 }
1263
1264 /*
1265  *      IP Autoconfig dispatcher.
1266  */
1267
1268 static int __init ip_auto_config(void)
1269 {
1270         __be32 addr;
1271 #ifdef IPCONFIG_DYNAMIC
1272         int retries = CONF_OPEN_RETRIES;
1273 #endif
1274
1275 #ifdef CONFIG_PROC_FS
1276         proc_net_fops_create(&init_net, "pnp", S_IRUGO, &pnp_seq_fops);
1277 #endif /* CONFIG_PROC_FS */
1278
1279         if (!ic_enable)
1280                 return 0;
1281
1282         DBG(("IP-Config: Entered.\n"));
1283 #ifdef IPCONFIG_DYNAMIC
1284  try_try_again:
1285 #endif
1286         /* Give hardware a chance to settle */
1287         msleep(CONF_PRE_OPEN);
1288
1289         /* Setup all network devices */
1290         if (ic_open_devs() < 0)
1291                 return -1;
1292
1293         /* Give drivers a chance to settle */
1294         ssleep(CONF_POST_OPEN);
1295
1296         /*
1297          * If the config information is insufficient (e.g., our IP address or
1298          * IP address of the boot server is missing or we have multiple network
1299          * interfaces and no default was set), use BOOTP or RARP to get the
1300          * missing values.
1301          */
1302         if (ic_myaddr == NONE ||
1303 #ifdef CONFIG_ROOT_NFS
1304             (root_server_addr == NONE
1305              && ic_servaddr == NONE
1306              && ROOT_DEV == Root_NFS) ||
1307 #endif
1308             ic_first_dev->next) {
1309 #ifdef IPCONFIG_DYNAMIC
1310                 if (ic_dynamic() < 0) {
1311                         ic_close_devs();
1312
1313                         /*
1314                          * I don't know why, but sometimes the
1315                          * eepro100 driver (at least) gets upset and
1316                          * doesn't work the first time it's opened.
1317                          * But then if you close it and reopen it, it
1318                          * works just fine.  So we need to try that at
1319                          * least once before giving up.
1320                          *
1321                          * Also, if the root will be NFS-mounted, we
1322                          * have nowhere to go if DHCP fails.  So we
1323                          * just have to keep trying forever.
1324                          *
1325                          *                              -- Chip
1326                          */
1327 #ifdef CONFIG_ROOT_NFS
1328                         if (ROOT_DEV ==  Root_NFS) {
1329                                 printk(KERN_ERR
1330                                         "IP-Config: Retrying forever (NFS root)...\n");
1331                                 goto try_try_again;
1332                         }
1333 #endif
1334
1335                         if (--retries) {
1336                                 printk(KERN_ERR
1337                                        "IP-Config: Reopening network devices...\n");
1338                                 goto try_try_again;
1339                         }
1340
1341                         /* Oh, well.  At least we tried. */
1342                         printk(KERN_ERR "IP-Config: Auto-configuration of network failed.\n");
1343                         return -1;
1344                 }
1345 #else /* !DYNAMIC */
1346                 printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
1347                 ic_close_devs();
1348                 return -1;
1349 #endif /* IPCONFIG_DYNAMIC */
1350         } else {
1351                 /* Device selected manually or only one device -> use it */
1352                 ic_dev = ic_first_dev->dev;
1353         }
1354
1355         addr = root_nfs_parse_addr(root_server_path);
1356         if (root_server_addr == NONE)
1357                 root_server_addr = addr;
1358
1359         /*
1360          * Use defaults whereever applicable.
1361          */
1362         if (ic_defaults() < 0)
1363                 return -1;
1364
1365         /*
1366          * Close all network devices except the device we've
1367          * autoconfigured and set up routes.
1368          */
1369         ic_close_devs();
1370         if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1371                 return -1;
1372
1373         /*
1374          * Record which protocol was actually used.
1375          */
1376 #ifdef IPCONFIG_DYNAMIC
1377         ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1378 #endif
1379
1380 #ifndef IPCONFIG_SILENT
1381         /*
1382          * Clue in the operator.
1383          */
1384         printk("IP-Config: Complete:");
1385         printk("\n     device=%s", ic_dev->name);
1386         printk(", addr=%pI4", &ic_myaddr);
1387         printk(", mask=%pI4", &ic_netmask);
1388         printk(", gw=%pI4", &ic_gateway);
1389         printk(",\n     host=%s, domain=%s, nis-domain=%s",
1390                utsname()->nodename, ic_domain, utsname()->domainname);
1391         printk(",\n     bootserver=%pI4", &ic_servaddr);
1392         printk(", rootserver=%pI4", &root_server_addr);
1393         printk(", rootpath=%s", root_server_path);
1394         printk("\n");
1395 #endif /* !SILENT */
1396
1397         return 0;
1398 }
1399
1400 late_initcall(ip_auto_config);
1401
1402
1403 /*
1404  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1405  *  command line parameter.  See Documentation/filesystems/nfsroot.txt.
1406  */
1407 static int __init ic_proto_name(char *name)
1408 {
1409         if (!strcmp(name, "on") || !strcmp(name, "any")) {
1410                 return 1;
1411         }
1412         if (!strcmp(name, "off") || !strcmp(name, "none")) {
1413                 return 0;
1414         }
1415 #ifdef CONFIG_IP_PNP_DHCP
1416         else if (!strcmp(name, "dhcp")) {
1417                 ic_proto_enabled &= ~IC_RARP;
1418                 return 1;
1419         }
1420 #endif
1421 #ifdef CONFIG_IP_PNP_BOOTP
1422         else if (!strcmp(name, "bootp")) {
1423                 ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1424                 return 1;
1425         }
1426 #endif
1427 #ifdef CONFIG_IP_PNP_RARP
1428         else if (!strcmp(name, "rarp")) {
1429                 ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1430                 return 1;
1431         }
1432 #endif
1433 #ifdef IPCONFIG_DYNAMIC
1434         else if (!strcmp(name, "both")) {
1435                 ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1436                 return 1;
1437         }
1438 #endif
1439         return 0;
1440 }
1441
1442 static int __init ip_auto_config_setup(char *addrs)
1443 {
1444         char *cp, *ip, *dp;
1445         int num = 0;
1446
1447         ic_set_manually = 1;
1448         ic_enable = 1;
1449
1450         /*
1451          * If any dhcp, bootp etc options are set, leave autoconfig on
1452          * and skip the below static IP processing.
1453          */
1454         if (ic_proto_name(addrs))
1455                 return 1;
1456
1457         /* If no static IP is given, turn off autoconfig and bail.  */
1458         if (*addrs == 0 ||
1459             strcmp(addrs, "off") == 0 ||
1460             strcmp(addrs, "none") == 0) {
1461                 ic_enable = 0;
1462                 return 1;
1463         }
1464
1465         /* Parse string for static IP assignment.  */
1466         ip = addrs;
1467         while (ip && *ip) {
1468                 if ((cp = strchr(ip, ':')))
1469                         *cp++ = '\0';
1470                 if (strlen(ip) > 0) {
1471                         DBG(("IP-Config: Parameter #%d: `%s'\n", num, ip));
1472                         switch (num) {
1473                         case 0:
1474                                 if ((ic_myaddr = in_aton(ip)) == ANY)
1475                                         ic_myaddr = NONE;
1476                                 break;
1477                         case 1:
1478                                 if ((ic_servaddr = in_aton(ip)) == ANY)
1479                                         ic_servaddr = NONE;
1480                                 break;
1481                         case 2:
1482                                 if ((ic_gateway = in_aton(ip)) == ANY)
1483                                         ic_gateway = NONE;
1484                                 break;
1485                         case 3:
1486                                 if ((ic_netmask = in_aton(ip)) == ANY)
1487                                         ic_netmask = NONE;
1488                                 break;
1489                         case 4:
1490                                 if ((dp = strchr(ip, '.'))) {
1491                                         *dp++ = '\0';
1492                                         strlcpy(utsname()->domainname, dp,
1493                                                 sizeof(utsname()->domainname));
1494                                 }
1495                                 strlcpy(utsname()->nodename, ip,
1496                                         sizeof(utsname()->nodename));
1497                                 ic_host_name_set = 1;
1498                                 break;
1499                         case 5:
1500                                 strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1501                                 break;
1502                         case 6:
1503                                 if (ic_proto_name(ip) == 0 &&
1504                                     ic_myaddr == NONE) {
1505                                         ic_enable = 0;
1506                                 }
1507                                 break;
1508                         }
1509                 }
1510                 ip = cp;
1511                 num++;
1512         }
1513
1514         return 1;
1515 }
1516
1517 static int __init nfsaddrs_config_setup(char *addrs)
1518 {
1519         return ip_auto_config_setup(addrs);
1520 }
1521
1522 static int __init vendor_class_identifier_setup(char *addrs)
1523 {
1524         if (strlcpy(vendor_class_identifier, addrs,
1525                     sizeof(vendor_class_identifier))
1526             >= sizeof(vendor_class_identifier))
1527                 printk(KERN_WARNING "DHCP: vendorclass too long, truncated to \"%s\"",
1528                        vendor_class_identifier);
1529         return 1;
1530 }
1531
1532 __setup("ip=", ip_auto_config_setup);
1533 __setup("nfsaddrs=", nfsaddrs_config_setup);
1534 __setup("dhcpclass=", vendor_class_identifier_setup);