net/ipv4/ipconfig.c

   1 /*
   2  *  $Id: ipconfig.c,v 1.46 2002/02/01 22:01:04 davem Exp $
   3  *
   4  *  Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or
   5  *  user-supplied information to configure own IP address and routes.
   6  *
   7  *  Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
   8  *
   9  *  Derived from network configuration code in fs/nfs/nfsroot.c,
  10  *  originally Copyright (C) 1995, 1996 Gero Kuhlmann and me.
  11  *
  12  *  BOOTP rewritten to construct and analyse packets itself instead
  13  *  of misusing the IP layer. num_bugs_causing_wrong_arp_replies--;
  14  *                                           -- MJ, December 1998
  15  *
  16  *  Fixed ip_auto_config_setup calling at startup in the new "Linker Magic"
  17  *  initialization scheme.
  18  *      - Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999
  19  *
  20  *  DHCP support added.  To users this looks like a whole separate
  21  *  protocol, but we know it's just a bag on the side of BOOTP.
  22  *              -- Chip Salzenberg <chip@valinux.com>, May 2000
  23  *
  24  *  Ported DHCP support from 2.2.16 to 2.4.0-test4
  25  *              -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000
  26  *
  27  *  Merged changes from 2.2.19 into 2.4.3
  28  *              -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001
  29  *
  30  *  Multiple Nameservers in /proc/net/pnp
  31  *              --  Josef Siemes <jsiemes@web.de>, Aug 2002
  32  */
  33
  34 #include <linux/config.h>
  35 #include <linux/types.h>
  36 #include <linux/string.h>
  37 #include <linux/kernel.h>
  38 #include <linux/jiffies.h>
  39 #include <linux/random.h>
  40 #include <linux/init.h>
  41 #include <linux/utsname.h>
  42 #include <linux/in.h>
  43 #include <linux/if.h>
  44 #include <linux/inet.h>
  45 #include <linux/netdevice.h>
  46 #include <linux/if_arp.h>
  47 #include <linux/skbuff.h>
  48 #include <linux/ip.h>
  49 #include <linux/socket.h>
  50 #include <linux/route.h>
  51 #include <linux/udp.h>
  52 #include <linux/proc_fs.h>
  53 #include <linux/seq_file.h>
  54 #include <linux/major.h>
  55 #include <linux/root_dev.h>
  56 #include <net/arp.h>
  57 #include <net/ip.h>
  58 #include <net/ipconfig.h>
  59
  60 #include <asm/uaccess.h>
  61 #include <net/checksum.h>
  62 #include <asm/processor.h>
  63
  64 /* Define this to allow debugging output */
  65 #undef IPCONFIG_DEBUG
  66
  67 #ifdef IPCONFIG_DEBUG
  68 #define DBG(x) printk x
  69 #else
  70 #define DBG(x) do { } while(0)
  71 #endif
  72
  73 #if defined(CONFIG_IP_PNP_DHCP)
  74 #define IPCONFIG_DHCP
  75 #endif
  76 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
  77 #define IPCONFIG_BOOTP
  78 #endif
  79 #if defined(CONFIG_IP_PNP_RARP)
  80 #define IPCONFIG_RARP
  81 #endif
  82 #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
  83 #define IPCONFIG_DYNAMIC
  84 #endif
  85
  86 /* Define the friendly delay before and after opening net devices */
  87 #define CONF_PRE_OPEN           (HZ/2)  /* Before opening: 1/2 second */
  88 #define CONF_POST_OPEN          (1*HZ)  /* After opening: 1 second */
  89
  90 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
  91 #define CONF_OPEN_RETRIES       2       /* (Re)open devices twice */
  92 #define CONF_SEND_RETRIES       6       /* Send six requests per open */
  93 #define CONF_INTER_TIMEOUT      (HZ/2)  /* Inter-device timeout: 1/2 second */
  94 #define CONF_BASE_TIMEOUT       (HZ*2)  /* Initial timeout: 2 seconds */
  95 #define CONF_TIMEOUT_RANDOM     (HZ)    /* Maximum amount of randomization */
  96 #define CONF_TIMEOUT_MULT       *7/4    /* Rate of timeout growth */
  97 #define CONF_TIMEOUT_MAX        (HZ*30) /* Maximum allowed timeout */
  98 #define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
  99                                            - '3' from resolv.h */
 100
 101
 102 /*
 103  * Public IP configuration
 104  */
 105
 106 /* This is used by platforms which might be able to set the ipconfig
 107  * variables using firmware environment vars.  If this is set, it will
 108  * ignore such firmware variables.
 109  */
 110 int ic_set_manually __initdata = 0;             /* IPconfig parameters set manually */
 111
 112 int ic_enable __initdata = 0;                   /* IP config enabled? */
 113
 114 /* Protocol choice */
 115 int ic_proto_enabled __initdata = 0
 116 #ifdef IPCONFIG_BOOTP
 117                         | IC_BOOTP
 118 #endif
 119 #ifdef CONFIG_IP_PNP_DHCP
 120                         | IC_USE_DHCP
 121 #endif
 122 #ifdef IPCONFIG_RARP
 123                         | IC_RARP
 124 #endif
 125                         ;
 126
 127 int ic_host_name_set __initdata = 0;            /* Host name set by us? */
 128
 129 u32 ic_myaddr = INADDR_NONE;            /* My IP address */
 130 u32 ic_netmask = INADDR_NONE;   /* Netmask for local subnet */
 131 u32 ic_gateway = INADDR_NONE;   /* Gateway IP address */
 132
 133 u32 ic_servaddr = INADDR_NONE;  /* Boot server IP address */
 134
 135 u32 root_server_addr = INADDR_NONE;     /* Address of NFS server */
 136 u8 root_server_path[256] = { 0, };      /* Path to mount as root */
 137
 138 /* Persistent data: */
 139
 140 int ic_proto_used;                      /* Protocol used, if any */
 141 u32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
 142 u8 ic_domain[64];               /* DNS (not NIS) domain name */
 143
 144 /*
 145  * Private state.
 146  */
 147
 148 /* Name of user-selected boot device */
 149 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
 150
 151 /* Protocols supported by available interfaces */
 152 static int ic_proto_have_if __initdata = 0;
 153
 154 #ifdef IPCONFIG_DYNAMIC
 155 static spinlock_t ic_recv_lock = SPIN_LOCK_UNLOCKED;
 156 static volatile int ic_got_reply __initdata = 0;    /* Proto(s) that replied */
 157 #endif
 158 #ifdef IPCONFIG_DHCP
 159 static int ic_dhcp_msgtype __initdata = 0;      /* DHCP msg type received */
 160 #endif
 161
 162
 163 /*
 164  *      Network devices
 165  */
 166
 167 struct ic_device {
 168         struct ic_device *next;
 169         struct net_device *dev;
 170         unsigned short flags;
 171         short able;
 172         u32 xid;
 173 };
 174
 175 static struct ic_device *ic_first_dev __initdata = NULL;/* List of open device */
 176 static struct net_device *ic_dev __initdata = NULL;     /* Selected device */
 177
 178 static int __init ic_open_devs(void)
 179 {
 180         struct ic_device *d, **last;
 181         struct net_device *dev;
 182         unsigned short oflags;
 183
 184         last = &ic_first_dev;
 185         rtnl_shlock();
 186
 187         /* bring loopback device up first */
 188         if (dev_change_flags(&loopback_dev, loopback_dev.flags | IFF_UP) < 0)
 189                 printk(KERN_ERR "IP-Config: Failed to open %s\n", loopback_dev.name);
 190
 191         for (dev = dev_base; dev; dev = dev->next) {
 192                 if (dev == &loopback_dev)
 193                         continue;
 194                 if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
 195                     (!(dev->flags & IFF_LOOPBACK) &&
 196                      (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
 197                      strncmp(dev->name, "dummy", 5))) {
 198                         int able = 0;
 199                         if (dev->mtu >= 364)
 200                                 able |= IC_BOOTP;
 201                         else
 202                                 printk(KERN_WARNING "DHCP/BOOTP: Ignoring device %s, MTU %d too small", dev->name, dev->mtu);
 203                         if (!(dev->flags & IFF_NOARP))
 204                                 able |= IC_RARP;
 205                         able &= ic_proto_enabled;
 206                         if (ic_proto_enabled && !able)
 207                                 continue;
 208                         oflags = dev->flags;
 209                         if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
 210                                 printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
 211                                 continue;
 212                         }
 213                         if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
 214                                 rtnl_shunlock();
 215                                 return -1;
 216                         }
 217                         d->dev = dev;
 218                         *last = d;
 219                         last = &d->next;
 220                         d->flags = oflags;
 221                         d->able = able;
 222                         if (able & IC_BOOTP)
 223                                 get_random_bytes(&d->xid, sizeof(u32));
 224                         else
 225                                 d->xid = 0;
 226                         ic_proto_have_if |= able;
 227                         DBG(("IP-Config: %s UP (able=%d, xid=%08x)\n",
 228                                 dev->name, able, d->xid));
 229                 }
 230         }
 231         rtnl_shunlock();
 232
 233         *last = NULL;
 234
 235         if (!ic_first_dev) {
 236                 if (user_dev_name[0])
 237                         printk(KERN_ERR "IP-Config: Device `%s' not found.\n", user_dev_name);
 238                 else
 239                         printk(KERN_ERR "IP-Config: No network devices available.\n");
 240                 return -1;
 241         }
 242         return 0;
 243 }
 244
 245 static void __init ic_close_devs(void)
 246 {
 247         struct ic_device *d, *next;
 248         struct net_device *dev;
 249
 250         rtnl_shlock();
 251         next = ic_first_dev;
 252         while ((d = next)) {
 253                 next = d->next;
 254                 dev = d->dev;
 255                 if (dev != ic_dev) {
 256                         DBG(("IP-Config: Downing %s\n", dev->name));
 257                         dev_change_flags(dev, d->flags);
 258                 }
 259                 kfree(d);
 260         }
 261         rtnl_shunlock();
 262 }
 263
 264 /*
 265  *      Interface to various network functions.
 266  */
 267
 268 static inline void
 269 set_sockaddr(struct sockaddr_in *sin, u32 addr, u16 port)
 270 {
 271         sin->sin_family = AF_INET;
 272         sin->sin_addr.s_addr = addr;
 273         sin->sin_port = port;
 274 }
 275
 276 static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
 277 {
 278         int res;
 279
 280         mm_segment_t oldfs = get_fs();
 281         set_fs(get_ds());
 282         res = devinet_ioctl(cmd, (struct ifreq __user *) arg);
 283         set_fs(oldfs);
 284         return res;
 285 }
 286
 287 static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg)
 288 {
 289         int res;
 290
 291         mm_segment_t oldfs = get_fs();
 292         set_fs(get_ds());
 293         res = ip_rt_ioctl(cmd, (void __user *) arg);
 294         set_fs(oldfs);
 295         return res;
 296 }
 297
 298 /*
 299  *      Set up interface addresses and routes.
 300  */
 301
 302 static int __init ic_setup_if(void)
 303 {
 304         struct ifreq ir;
 305         struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
 306         int err;
 307
 308         memset(&ir, 0, sizeof(ir));
 309         strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->name);
 310         set_sockaddr(sin, ic_myaddr, 0);
 311         if ((err = ic_dev_ioctl(SIOCSIFADDR, &ir)) < 0) {
 312                 printk(KERN_ERR "IP-Config: Unable to set interface address (%d).\n", err);
 313                 return -1;
 314         }
 315         set_sockaddr(sin, ic_netmask, 0);
 316         if ((err = ic_dev_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
 317                 printk(KERN_ERR "IP-Config: Unable to set interface netmask (%d).\n", err);
 318                 return -1;
 319         }
 320         set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
 321         if ((err = ic_dev_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
 322                 printk(KERN_ERR "IP-Config: Unable to set interface broadcast address (%d).\n", err);
 323                 return -1;
 324         }
 325         return 0;
 326 }
 327
 328 static int __init ic_setup_routes(void)
 329 {
 330         /* No need to setup device routes, only the default route... */
 331
 332         if (ic_gateway != INADDR_NONE) {
 333                 struct rtentry rm;
 334                 int err;
 335
 336                 memset(&rm, 0, sizeof(rm));
 337                 if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
 338                         printk(KERN_ERR "IP-Config: Gateway not on directly connected network.\n");
 339                         return -1;
 340                 }
 341                 set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
 342                 set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
 343                 set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
 344                 rm.rt_flags = RTF_UP | RTF_GATEWAY;
 345                 if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) {
 346                         printk(KERN_ERR "IP-Config: Cannot add default route (%d).\n", err);
 347                         return -1;
 348                 }
 349         }
 350
 351         return 0;
 352 }
 353
 354 /*
 355  *      Fill in default values for all missing parameters.
 356  */
 357
 358 static int __init ic_defaults(void)
 359 {
 360         /*
 361          *      At this point we have no userspace running so need not
 362          *      claim locks on system_utsname
 363          */
 364
 365         if (!ic_host_name_set)
 366                 sprintf(system_utsname.nodename, "%u.%u.%u.%u", NIPQUAD(ic_myaddr));
 367
 368         if (root_server_addr == INADDR_NONE)
 369                 root_server_addr = ic_servaddr;
 370
 371         if (ic_netmask == INADDR_NONE) {
 372                 if (IN_CLASSA(ntohl(ic_myaddr)))
 373                         ic_netmask = htonl(IN_CLASSA_NET);
 374                 else if (IN_CLASSB(ntohl(ic_myaddr)))
 375                         ic_netmask = htonl(IN_CLASSB_NET);
 376                 else if (IN_CLASSC(ntohl(ic_myaddr)))
 377                         ic_netmask = htonl(IN_CLASSC_NET);
 378                 else {
 379                         printk(KERN_ERR "IP-Config: Unable to guess netmask for address %u.%u.%u.%u\n",
 380                                 NIPQUAD(ic_myaddr));
 381                         return -1;
 382                 }
 383                 printk("IP-Config: Guessing netmask %u.%u.%u.%u\n", NIPQUAD(ic_netmask));
 384         }
 385
 386         return 0;
 387 }
 388
 389 /*
 390  *      RARP support.
 391  */
 392
 393 #ifdef IPCONFIG_RARP
 394
 395 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt);
 396
 397 static struct packet_type rarp_packet_type __initdata = {
 398         .type = __constant_htons(ETH_P_RARP),
 399         .func = ic_rarp_recv,
 400 };
 401
 402 static inline void ic_rarp_init(void)
 403 {
 404         dev_add_pack(&rarp_packet_type);
 405 }
 406
 407 static inline void ic_rarp_cleanup(void)
 408 {
 409         dev_remove_pack(&rarp_packet_type);
 410 }
 411
 412 /*
 413  *  Process received RARP packet.
 414  */
 415 static int __init
 416 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt)
 417 {
 418         struct arphdr *rarp;
 419         unsigned char *rarp_ptr;
 420         unsigned long sip, tip;
 421         unsigned char *sha, *tha;               /* s for "source", t for "target" */
 422         struct ic_device *d;
 423
 424         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
 425                 return NET_RX_DROP;
 426
 427         if (!pskb_may_pull(skb, sizeof(struct arphdr)))
 428                 goto drop;
 429
 430         /* Basic sanity checks can be done without the lock.  */
 431         rarp = (struct arphdr *)skb->h.raw;
 432
 433         /* If this test doesn't pass, it's not IP, or we should
 434          * ignore it anyway.
 435          */
 436         if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
 437                 goto drop;
 438
 439         /* If it's not a RARP reply, delete it. */
 440         if (rarp->ar_op != htons(ARPOP_RREPLY))
 441                 goto drop;
 442
 443         /* If it's not Ethernet, delete it. */
 444         if (rarp->ar_pro != htons(ETH_P_IP))
 445                 goto drop;
 446
 447         if (!pskb_may_pull(skb,
 448                            sizeof(struct arphdr) +
 449                            (2 * dev->addr_len) +
 450                            (2 * 4)))
 451                 goto drop;
 452
 453         /* OK, it is all there and looks valid, process... */
 454         rarp = (struct arphdr *)skb->h.raw;
 455         rarp_ptr = (unsigned char *) (rarp + 1);
 456
 457         /* One reply at a time, please. */
 458         spin_lock(&ic_recv_lock);
 459
 460         /* If we already have a reply, just drop the packet */
 461         if (ic_got_reply)
 462                 goto drop_unlock;
 463
 464         /* Find the ic_device that the packet arrived on */
 465         d = ic_first_dev;
 466         while (d && d->dev != dev)
 467                 d = d->next;
 468         if (!d)
 469                 goto drop_unlock;       /* should never happen */
 470
 471         /* Extract variable-width fields */
 472         sha = rarp_ptr;
 473         rarp_ptr += dev->addr_len;
 474         memcpy(&sip, rarp_ptr, 4);
 475         rarp_ptr += 4;
 476         tha = rarp_ptr;
 477         rarp_ptr += dev->addr_len;
 478         memcpy(&tip, rarp_ptr, 4);
 479
 480         /* Discard packets which are not meant for us. */
 481         if (memcmp(tha, dev->dev_addr, dev->addr_len))
 482                 goto drop_unlock;
 483
 484         /* Discard packets which are not from specified server. */
 485         if (ic_servaddr != INADDR_NONE && ic_servaddr != sip)
 486                 goto drop_unlock;
 487
 488         /* We have a winner! */
 489         ic_dev = dev;
 490         if (ic_myaddr == INADDR_NONE)
 491                 ic_myaddr = tip;
 492         ic_servaddr = sip;
 493         ic_got_reply = IC_RARP;
 494
 495 drop_unlock:
 496         /* Show's over.  Nothing to see here.  */
 497         spin_unlock(&ic_recv_lock);
 498
 499 drop:
 500         /* Throw the packet out. */
 501         kfree_skb(skb);
 502         return 0;
 503 }
 504
 505
 506 /*
 507  *  Send RARP request packet over a single interface.
 508  */
 509 static void __init ic_rarp_send_if(struct ic_device *d)
 510 {
 511         struct net_device *dev = d->dev;
 512         arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
 513                  dev->dev_addr, dev->dev_addr);
 514 }
 515 #endif
 516
 517 /*
 518  *      DHCP/BOOTP support.
 519  */
 520
 521 #ifdef IPCONFIG_BOOTP
 522
 523 struct bootp_pkt {              /* BOOTP packet format */
 524         struct iphdr iph;       /* IP header */
 525         struct udphdr udph;     /* UDP header */
 526         u8 op;                  /* 1=request, 2=reply */
 527         u8 htype;               /* HW address type */
 528         u8 hlen;                /* HW address length */
 529         u8 hops;                /* Used only by gateways */
 530         u32 xid;                /* Transaction ID */
 531         u16 secs;               /* Seconds since we started */
 532         u16 flags;              /* Just what it says */
 533         u32 client_ip;          /* Client's IP address if known */
 534         u32 your_ip;            /* Assigned IP address */
 535         u32 server_ip;          /* (Next, e.g. NFS) Server's IP address */
 536         u32 relay_ip;           /* IP address of BOOTP relay */
 537         u8 hw_addr[16];         /* Client's HW address */
 538         u8 serv_name[64];       /* Server host name */
 539         u8 boot_file[128];      /* Name of boot file */
 540         u8 exten[312];          /* DHCP options / BOOTP vendor extensions */
 541 };
 542
 543 /* packet ops */
 544 #define BOOTP_REQUEST   1
 545 #define BOOTP_REPLY     2
 546
 547 /* DHCP message types */
 548 #define DHCPDISCOVER    1
 549 #define DHCPOFFER       2
 550 #define DHCPREQUEST     3
 551 #define DHCPDECLINE     4
 552 #define DHCPACK         5
 553 #define DHCPNAK         6
 554 #define DHCPRELEASE     7
 555 #define DHCPINFORM      8
 556
 557 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt);
 558
 559 static struct packet_type bootp_packet_type __initdata = {
 560         .type = __constant_htons(ETH_P_IP),
 561         .func = ic_bootp_recv,
 562 };
 563
 564
 565 /*
 566  *  Initialize DHCP/BOOTP extension fields in the request.
 567  */
 568
 569 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
 570
 571 #ifdef IPCONFIG_DHCP
 572
 573 static void __init
 574 ic_dhcp_init_options(u8 *options)
 575 {
 576         u8 mt = ((ic_servaddr == INADDR_NONE)
 577                  ? DHCPDISCOVER : DHCPREQUEST);
 578         u8 *e = options;
 579
 580 #ifdef IPCONFIG_DEBUG
 581         printk("DHCP: Sending message type %d\n", mt);
 582 #endif
 583
 584         memcpy(e, ic_bootp_cookie, 4);  /* RFC1048 Magic Cookie */
 585         e += 4;
 586
 587         *e++ = 53;              /* DHCP message type */
 588         *e++ = 1;
 589         *e++ = mt;
 590
 591         if (mt == DHCPREQUEST) {
 592                 *e++ = 54;      /* Server ID (IP address) */
 593                 *e++ = 4;
 594                 memcpy(e, &ic_servaddr, 4);
 595                 e += 4;
 596
 597                 *e++ = 50;      /* Requested IP address */
 598                 *e++ = 4;
 599                 memcpy(e, &ic_myaddr, 4);
 600                 e += 4;
 601         }
 602
 603         /* always? */
 604         {
 605                 static const u8 ic_req_params[] = {
 606                         1,      /* Subnet mask */
 607                         3,      /* Default gateway */
 608                         6,      /* DNS server */
 609                         12,     /* Host name */
 610                         15,     /* Domain name */
 611                         17,     /* Boot path */
 612                         40,     /* NIS domain name */
 613                 };
 614
 615                 *e++ = 55;      /* Parameter request list */
 616                 *e++ = sizeof(ic_req_params);
 617                 memcpy(e, ic_req_params, sizeof(ic_req_params));
 618                 e += sizeof(ic_req_params);
 619         }
 620
 621         *e++ = 255;     /* End of the list */
 622 }
 623
 624 #endif /* IPCONFIG_DHCP */
 625
 626 static void __init ic_bootp_init_ext(u8 *e)
 627 {
 628         memcpy(e, ic_bootp_cookie, 4);  /* RFC1048 Magic Cookie */
 629         e += 4;
 630         *e++ = 1;               /* Subnet mask request */
 631         *e++ = 4;
 632         e += 4;
 633         *e++ = 3;               /* Default gateway request */
 634         *e++ = 4;
 635         e += 4;
 636         *e++ = 5;               /* Name server request */
 637         *e++ = 8;
 638         e += 8;
 639         *e++ = 12;              /* Host name request */
 640         *e++ = 32;
 641         e += 32;
 642         *e++ = 40;              /* NIS Domain name request */
 643         *e++ = 32;
 644         e += 32;
 645         *e++ = 17;              /* Boot path */
 646         *e++ = 40;
 647         e += 40;
 648
 649         *e++ = 57;              /* set extension buffer size for reply */
 650         *e++ = 2;
 651         *e++ = 1;               /* 128+236+8+20+14, see dhcpd sources */
 652         *e++ = 150;
 653
 654         *e++ = 255;             /* End of the list */
 655 }
 656
 657
 658 /*
 659  *  Initialize the DHCP/BOOTP mechanism.
 660  */
 661 static inline void ic_bootp_init(void)
 662 {
 663         int i;
 664
 665         for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
 666                 ic_nameservers[i] = INADDR_NONE;
 667
 668         dev_add_pack(&bootp_packet_type);
 669 }
 670
 671
 672 /*
 673  *  DHCP/BOOTP cleanup.
 674  */
 675 static inline void ic_bootp_cleanup(void)
 676 {
 677         dev_remove_pack(&bootp_packet_type);
 678 }
 679
 680
 681 /*
 682  *  Send DHCP/BOOTP request to single interface.
 683  */
 684 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
 685 {
 686         struct net_device *dev = d->dev;
 687         struct sk_buff *skb;
 688         struct bootp_pkt *b;
 689         int hh_len = LL_RESERVED_SPACE(dev);
 690         struct iphdr *h;
 691
 692         /* Allocate packet */
 693         skb = alloc_skb(sizeof(struct bootp_pkt) + hh_len + 15, GFP_KERNEL);
 694         if (!skb)
 695                 return;
 696         skb_reserve(skb, hh_len);
 697         b = (struct bootp_pkt *) skb_put(skb, sizeof(struct bootp_pkt));
 698         memset(b, 0, sizeof(struct bootp_pkt));
 699
 700         /* Construct IP header */
 701         skb->nh.iph = h = &b->iph;
 702         h->version = 4;
 703         h->ihl = 5;
 704         h->tot_len = htons(sizeof(struct bootp_pkt));
 705         h->frag_off = htons(IP_DF);
 706         h->ttl = 64;
 707         h->protocol = IPPROTO_UDP;
 708         h->daddr = INADDR_BROADCAST;
 709         h->check = ip_fast_csum((unsigned char *) h, h->ihl);
 710
 711         /* Construct UDP header */
 712         b->udph.source = htons(68);
 713         b->udph.dest = htons(67);
 714         b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
 715         /* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
 716
 717         /* Construct DHCP/BOOTP header */
 718         b->op = BOOTP_REQUEST;
 719         if (dev->type < 256) /* check for false types */
 720                 b->htype = dev->type;
 721         else if (dev->type == ARPHRD_IEEE802_TR) /* fix for token ring */
 722                 b->htype = ARPHRD_IEEE802;
 723         else if (dev->type == ARPHRD_FDDI)
 724                 b->htype = ARPHRD_ETHER;
 725         else {
 726                 printk("Unknown ARP type 0x%04x for device %s\n", dev->type, dev->name);
 727                 b->htype = dev->type; /* can cause undefined behavior */
 728         }
 729         b->hlen = dev->addr_len;
 730         b->your_ip = INADDR_NONE;
 731         b->server_ip = INADDR_NONE;
 732         memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
 733         b->secs = htons(jiffies_diff / HZ);
 734         b->xid = d->xid;
 735
 736         /* add DHCP options or BOOTP extensions */
 737 #ifdef IPCONFIG_DHCP
 738         if (ic_proto_enabled & IC_USE_DHCP)
 739                 ic_dhcp_init_options(b->exten);
 740         else
 741 #endif
 742                 ic_bootp_init_ext(b->exten);
 743
 744         /* Chain packet down the line... */
 745         skb->dev = dev;
 746         skb->protocol = htons(ETH_P_IP);
 747         if ((dev->hard_header &&
 748              dev->hard_header(skb, dev, ntohs(skb->protocol), dev->broadcast, dev->dev_addr, skb->len) < 0) ||
 749             dev_queue_xmit(skb) < 0)
 750                 printk("E");
 751 }
 752
 753
 754 /*
 755  *  Copy BOOTP-supplied string if not already set.
 756  */
 757 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
 758 {
 759         if (!len)
 760                 return 0;
 761         if (len > max-1)
 762                 len = max-1;
 763         memcpy(dest, src, len);
 764         dest[len] = '\0';
 765         return 1;
 766 }
 767
 768
 769 /*
 770  *  Process BOOTP extensions.
 771  */
 772 static void __init ic_do_bootp_ext(u8 *ext)
 773 {
 774        u8 servers;
 775        int i;
 776
 777 #ifdef IPCONFIG_DEBUG
 778         u8 *c;
 779
 780         printk("DHCP/BOOTP: Got extension %d:",*ext);
 781         for(c=ext+2; c<ext+2+ext[1]; c++)
 782                 printk(" %02x", *c);
 783         printk("\n");
 784 #endif
 785
 786         switch (*ext++) {
 787                 case 1:         /* Subnet mask */
 788                         if (ic_netmask == INADDR_NONE)
 789                                 memcpy(&ic_netmask, ext+1, 4);
 790                         break;
 791                 case 3:         /* Default gateway */
 792                         if (ic_gateway == INADDR_NONE)
 793                                 memcpy(&ic_gateway, ext+1, 4);
 794                         break;
 795                 case 6:         /* DNS server */
 796                         servers= *ext/4;
 797                         if (servers > CONF_NAMESERVERS_MAX)
 798                                 servers = CONF_NAMESERVERS_MAX;
 799                         for (i = 0; i < servers; i++) {
 800                                 if (ic_nameservers[i] == INADDR_NONE)
 801                                         memcpy(&ic_nameservers[i], ext+1+4*i, 4);
 802                         }
 803                         break;
 804                 case 12:        /* Host name */
 805                         ic_bootp_string(system_utsname.nodename, ext+1, *ext, __NEW_UTS_LEN);
 806                         ic_host_name_set = 1;
 807                         break;
 808                 case 15:        /* Domain name (DNS) */
 809                         ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
 810                         break;
 811                 case 17:        /* Root path */
 812                         if (!root_server_path[0])
 813                                 ic_bootp_string(root_server_path, ext+1, *ext, sizeof(root_server_path));
 814                         break;
 815                 case 40:        /* NIS Domain name (_not_ DNS) */
 816                         ic_bootp_string(system_utsname.domainname, ext+1, *ext, __NEW_UTS_LEN);
 817                         break;
 818         }
 819 }
 820
 821
 822 /*
 823  *  Receive BOOTP reply.
 824  */
 825 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt)
 826 {
 827         struct bootp_pkt *b;
 828         struct iphdr *h;
 829         struct ic_device *d;
 830         int len, ext_len;
 831
 832         /* Perform verifications before taking the lock.  */
 833         if (skb->pkt_type == PACKET_OTHERHOST)
 834                 goto drop;
 835
 836         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
 837                 return NET_RX_DROP;
 838
 839         if (!pskb_may_pull(skb,
 840                            sizeof(struct iphdr) +
 841                            sizeof(struct udphdr)))
 842                 goto drop;
 843
 844         b = (struct bootp_pkt *) skb->nh.iph;
 845         h = &b->iph;
 846
 847         if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
 848                 goto drop;
 849
 850         /* Fragments are not supported */
 851         if (h->frag_off & htons(IP_OFFSET | IP_MF)) {
 852                 if (net_ratelimit())
 853                         printk(KERN_ERR "DHCP/BOOTP: Ignoring fragmented "
 854                                "reply.\n");
 855                 goto drop;
 856         }
 857
 858         if (skb->len < ntohs(h->tot_len))
 859                 goto drop;
 860
 861         if (ip_fast_csum((char *) h, h->ihl))
 862                 goto drop;
 863
 864         if (b->udph.source != htons(67) || b->udph.dest != htons(68))
 865                 goto drop;
 866
 867         if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
 868                 goto drop;
 869
 870         len = ntohs(b->udph.len) - sizeof(struct udphdr);
 871         ext_len = len - (sizeof(*b) -
 872                          sizeof(struct iphdr) -
 873                          sizeof(struct udphdr) -
 874                          sizeof(b->exten));
 875         if (ext_len < 0)
 876                 goto drop;
 877
 878         /* Ok the front looks good, make sure we can get at the rest.  */
 879         if (!pskb_may_pull(skb, skb->len))
 880                 goto drop;
 881
 882         b = (struct bootp_pkt *) skb->nh.iph;
 883         h = &b->iph;
 884
 885         /* One reply at a time, please. */
 886         spin_lock(&ic_recv_lock);
 887
 888         /* If we already have a reply, just drop the packet */
 889         if (ic_got_reply)
 890                 goto drop_unlock;
 891
 892         /* Find the ic_device that the packet arrived on */
 893         d = ic_first_dev;
 894         while (d && d->dev != dev)
 895                 d = d->next;
 896         if (!d)
 897                 goto drop_unlock;  /* should never happen */
 898
 899         /* Is it a reply to our BOOTP request? */
 900         if (b->op != BOOTP_REPLY ||
 901             b->xid != d->xid) {
 902                 if (net_ratelimit())
 903                         printk(KERN_ERR "DHCP/BOOTP: Reply not for us, "
 904                                "op[%x] xid[%x]\n",
 905                                b->op, b->xid);
 906                 goto drop_unlock;
 907         }
 908
 909         /* Parse extensions */
 910         if (ext_len >= 4 &&
 911             !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
 912                 u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
 913                 u8 *ext;
 914
 915 #ifdef IPCONFIG_DHCP
 916                 if (ic_proto_enabled & IC_USE_DHCP) {
 917                         u32 server_id = INADDR_NONE;
 918                         int mt = 0;
 919
 920                         ext = &b->exten[4];
 921                         while (ext < end && *ext != 0xff) {
 922                                 u8 *opt = ext++;
 923                                 if (*opt == 0)  /* Padding */
 924                                         continue;
 925                                 ext += *ext + 1;
 926                                 if (ext >= end)
 927                                         break;
 928                                 switch (*opt) {
 929                                 case 53:        /* Message type */
 930                                         if (opt[1])
 931                                                 mt = opt[2];
 932                                         break;
 933                                 case 54:        /* Server ID (IP address) */
 934                                         if (opt[1] >= 4)
 935                                                 memcpy(&server_id, opt + 2, 4);
 936                                         break;
 937                                 };
 938                         }
 939
 940 #ifdef IPCONFIG_DEBUG
 941                         printk("DHCP: Got message type %d\n", mt);
 942 #endif
 943
 944                         switch (mt) {
 945                         case DHCPOFFER:
 946                                 /* While in the process of accepting one offer,
 947                                  * ignore all others.
 948                                  */
 949                                 if (ic_myaddr != INADDR_NONE)
 950                                         goto drop_unlock;
 951
 952                                 /* Let's accept that offer. */
 953                                 ic_myaddr = b->your_ip;
 954                                 ic_servaddr = server_id;
 955 #ifdef IPCONFIG_DEBUG
 956                                 printk("DHCP: Offered address %u.%u.%u.%u",
 957                                        NIPQUAD(ic_myaddr));
 958                                 printk(" by server %u.%u.%u.%u\n",
 959                                        NIPQUAD(ic_servaddr));
 960 #endif
 961                                 /* The DHCP indicated server address takes
 962                                  * precedence over the bootp header one if
 963                                  * they are different.
 964                                  */
 965                                 if ((server_id != INADDR_NONE) &&
 966                                     (b->server_ip != server_id))
 967                                         b->server_ip = ic_servaddr;
 968                                 break;
 969
 970                         case DHCPACK:
 971                                 if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
 972                                         goto drop_unlock;
 973
 974                                 /* Yeah! */
 975                                 break;
 976
 977                         default:
 978                                 /* Urque.  Forget it*/
 979                                 ic_myaddr = INADDR_NONE;
 980                                 ic_servaddr = INADDR_NONE;
 981                                 goto drop_unlock;
 982                         };
 983
 984                         ic_dhcp_msgtype = mt;
 985
 986                 }
 987 #endif /* IPCONFIG_DHCP */
 988
 989                 ext = &b->exten[4];
 990                 while (ext < end && *ext != 0xff) {
 991                         u8 *opt = ext++;
 992                         if (*opt == 0)  /* Padding */
 993                                 continue;
 994                         ext += *ext + 1;
 995                         if (ext < end)
 996                                 ic_do_bootp_ext(opt);
 997                 }
 998         }
 999
1000         /* We have a winner! */
1001         ic_dev = dev;
1002         ic_myaddr = b->your_ip;
1003         ic_servaddr = b->server_ip;
1004         if (ic_gateway == INADDR_NONE && b->relay_ip)
1005                 ic_gateway = b->relay_ip;
1006         if (ic_nameservers[0] == INADDR_NONE)
1007                 ic_nameservers[0] = ic_servaddr;
1008         ic_got_reply = IC_BOOTP;
1009
1010 drop_unlock:
1011         /* Show's over.  Nothing to see here.  */
1012         spin_unlock(&ic_recv_lock);
1013
1014 drop:
1015         /* Throw the packet out. */
1016         kfree_skb(skb);
1017
1018         return 0;
1019 }
1020
1021
1022 #endif
1023
1024
1025 /*
1026  *      Dynamic IP configuration -- DHCP, BOOTP, RARP.
1027  */
1028
1029 #ifdef IPCONFIG_DYNAMIC
1030
1031 static int __init ic_dynamic(void)
1032 {
1033         int retries;
1034         struct ic_device *d;
1035         unsigned long start_jiffies, timeout, jiff;
1036         int do_bootp = ic_proto_have_if & IC_BOOTP;
1037         int do_rarp = ic_proto_have_if & IC_RARP;
1038
1039         /*
1040          * If none of DHCP/BOOTP/RARP was selected, return with an error.
1041          * This routine gets only called when some pieces of information
1042          * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1043          */
1044         if (!ic_proto_enabled) {
1045                 printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
1046                 return -1;
1047         }
1048
1049 #ifdef IPCONFIG_BOOTP
1050         if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1051                 printk(KERN_ERR "DHCP/BOOTP: No suitable device found.\n");
1052 #endif
1053 #ifdef IPCONFIG_RARP
1054         if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1055                 printk(KERN_ERR "RARP: No suitable device found.\n");
1056 #endif
1057
1058         if (!ic_proto_have_if)
1059                 /* Error message already printed */
1060                 return -1;
1061
1062         /*
1063          * Setup protocols
1064          */
1065 #ifdef IPCONFIG_BOOTP
1066         if (do_bootp)
1067                 ic_bootp_init();
1068 #endif
1069 #ifdef IPCONFIG_RARP
1070         if (do_rarp)
1071                 ic_rarp_init();
1072 #endif
1073
1074         /*
1075          * Send requests and wait, until we get an answer. This loop
1076          * seems to be a terrible waste of CPU time, but actually there is
1077          * only one process running at all, so we don't need to use any
1078          * scheduler functions.
1079          * [Actually we could now, but the nothing else running note still
1080          *  applies.. - AC]
1081          */
1082         printk(KERN_NOTICE "Sending %s%s%s requests .",
1083                do_bootp
1084                 ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1085                (do_bootp && do_rarp) ? " and " : "",
1086                do_rarp ? "RARP" : "");
1087
1088         start_jiffies = jiffies;
1089         d = ic_first_dev;
1090         retries = CONF_SEND_RETRIES;
1091         get_random_bytes(&timeout, sizeof(timeout));
1092         timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned) CONF_TIMEOUT_RANDOM);
1093         for(;;) {
1094 #ifdef IPCONFIG_BOOTP
1095                 if (do_bootp && (d->able & IC_BOOTP))
1096                         ic_bootp_send_if(d, jiffies - start_jiffies);
1097 #endif
1098 #ifdef IPCONFIG_RARP
1099                 if (do_rarp && (d->able & IC_RARP))
1100                         ic_rarp_send_if(d);
1101 #endif
1102
1103                 jiff = jiffies + (d->next ? CONF_INTER_TIMEOUT : timeout);
1104                 while (time_before(jiffies, jiff) && !ic_got_reply) {
1105                         barrier();
1106                         cpu_relax();
1107                 }
1108 #ifdef IPCONFIG_DHCP
1109                 /* DHCP isn't done until we get a DHCPACK. */
1110                 if ((ic_got_reply & IC_BOOTP)
1111                     && (ic_proto_enabled & IC_USE_DHCP)
1112                     && ic_dhcp_msgtype != DHCPACK)
1113                 {
1114                         ic_got_reply = 0;
1115                         printk(",");
1116                         continue;
1117                 }
1118 #endif /* IPCONFIG_DHCP */
1119
1120                 if (ic_got_reply) {
1121                         printk(" OK\n");
1122                         break;
1123                 }
1124
1125                 if ((d = d->next))
1126                         continue;
1127
1128                 if (! --retries) {
1129                         printk(" timed out!\n");
1130                         break;
1131                 }
1132
1133                 d = ic_first_dev;
1134
1135                 timeout = timeout CONF_TIMEOUT_MULT;
1136                 if (timeout > CONF_TIMEOUT_MAX)
1137                         timeout = CONF_TIMEOUT_MAX;
1138
1139                 printk(".");
1140         }
1141
1142 #ifdef IPCONFIG_BOOTP
1143         if (do_bootp)
1144                 ic_bootp_cleanup();
1145 #endif
1146 #ifdef IPCONFIG_RARP
1147         if (do_rarp)
1148                 ic_rarp_cleanup();
1149 #endif
1150
1151         if (!ic_got_reply)
1152                 return -1;
1153
1154         printk("IP-Config: Got %s answer from %u.%u.%u.%u, ",
1155                 ((ic_got_reply & IC_RARP) ? "RARP"
1156                  : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1157                 NIPQUAD(ic_servaddr));
1158         printk("my address is %u.%u.%u.%u\n", NIPQUAD(ic_myaddr));
1159
1160         return 0;
1161 }
1162
1163 #endif /* IPCONFIG_DYNAMIC */
1164
1165 #ifdef CONFIG_PROC_FS
1166
1167 static int pnp_seq_show(struct seq_file *seq, void *v)
1168 {
1169         int i;
1170
1171         if (ic_proto_used & IC_PROTO)
1172                 seq_printf(seq, "#PROTO: %s\n",
1173                            (ic_proto_used & IC_RARP) ? "RARP"
1174                            : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1175         else
1176                 seq_puts(seq, "#MANUAL\n");
1177
1178         if (ic_domain[0])
1179                 seq_printf(seq,
1180                            "domain %s\n", ic_domain);
1181         for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1182                 if (ic_nameservers[i] != INADDR_NONE)
1183                         seq_printf(seq,
1184                                    "nameserver %u.%u.%u.%u\n",
1185                                    NIPQUAD(ic_nameservers[i]));
1186         }
1187         if (ic_servaddr != INADDR_NONE)
1188                 seq_printf(seq,
1189                            "bootserver %u.%u.%u.%u\n",
1190                            NIPQUAD(ic_servaddr));
1191         return 0;
1192 }
1193
1194 static int pnp_seq_open(struct inode *indoe, struct file *file)
1195 {
1196         return single_open(file, pnp_seq_show, NULL);
1197 }
1198
1199 static struct file_operations pnp_seq_fops = {
1200         .owner          = THIS_MODULE,
1201         .open           = pnp_seq_open,
1202         .read           = seq_read,
1203         .llseek         = seq_lseek,
1204         .release        = single_release,
1205 };
1206 #endif /* CONFIG_PROC_FS */
1207
1208 /*
1209  *  Extract IP address from the parameter string if needed. Note that we
1210  *  need to have root_server_addr set _before_ IPConfig gets called as it
1211  *  can override it.
1212  */
1213 u32 __init root_nfs_parse_addr(char *name)
1214 {
1215         u32 addr;
1216         int octets = 0;
1217         char *cp, *cq;
1218
1219         cp = cq = name;
1220         while (octets < 4) {
1221                 while (*cp >= '0' && *cp <= '9')
1222                         cp++;
1223                 if (cp == cq || cp - cq > 3)
1224                         break;
1225                 if (*cp == '.' || octets == 3)
1226                         octets++;
1227                 if (octets < 4)
1228                         cp++;
1229                 cq = cp;
1230         }
1231         if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1232                 if (*cp == ':')
1233                         *cp++ = '\0';
1234                 addr = in_aton(name);
1235                 strcpy(name, cp);
1236         } else
1237                 addr = INADDR_NONE;
1238
1239         return addr;
1240 }
1241
1242 /*
1243  *      IP Autoconfig dispatcher.
1244  */
1245
1246 static int __init ip_auto_config(void)
1247 {
1248         unsigned long jiff;
1249         u32 addr;
1250
1251 #ifdef CONFIG_PROC_FS
1252         proc_net_fops_create("pnp", S_IRUGO, &pnp_seq_fops);
1253 #endif /* CONFIG_PROC_FS */
1254
1255         if (!ic_enable)
1256                 return 0;
1257
1258         DBG(("IP-Config: Entered.\n"));
1259 #ifdef IPCONFIG_DYNAMIC
1260  try_try_again:
1261 #endif
1262         /* Give hardware a chance to settle */
1263         jiff = jiffies + CONF_PRE_OPEN;
1264         while (time_before(jiffies, jiff))
1265                 cpu_relax();
1266
1267         /* Setup all network devices */
1268         if (ic_open_devs() < 0)
1269                 return -1;
1270
1271         /* Give drivers a chance to settle */
1272         jiff = jiffies + CONF_POST_OPEN;
1273         while (time_before(jiffies, jiff))
1274                 cpu_relax();
1275
1276         /*
1277          * If the config information is insufficient (e.g., our IP address or
1278          * IP address of the boot server is missing or we have multiple network
1279          * interfaces and no default was set), use BOOTP or RARP to get the
1280          * missing values.
1281          */
1282         if (ic_myaddr == INADDR_NONE ||
1283 #ifdef CONFIG_ROOT_NFS
1284             (MAJOR(ROOT_DEV) == UNNAMED_MAJOR
1285              && root_server_addr == INADDR_NONE
1286              && ic_servaddr == INADDR_NONE) ||
1287 #endif
1288             ic_first_dev->next) {
1289 #ifdef IPCONFIG_DYNAMIC
1290
1291                 int retries = CONF_OPEN_RETRIES;
1292
1293                 if (ic_dynamic() < 0) {
1294                         ic_close_devs();
1295
1296                         /*
1297                          * I don't know why, but sometimes the
1298                          * eepro100 driver (at least) gets upset and
1299                          * doesn't work the first time it's opened.
1300                          * But then if you close it and reopen it, it
1301                          * works just fine.  So we need to try that at
1302                          * least once before giving up.
1303                          *
1304                          * Also, if the root will be NFS-mounted, we
1305                          * have nowhere to go if DHCP fails.  So we
1306                          * just have to keep trying forever.
1307                          *
1308                          *                              -- Chip
1309                          */
1310 #ifdef CONFIG_ROOT_NFS
1311                         if (ROOT_DEV ==  Root_NFS) {
1312                                 printk(KERN_ERR
1313                                         "IP-Config: Retrying forever (NFS root)...\n");
1314                                 goto try_try_again;
1315                         }
1316 #endif
1317
1318                         if (--retries) {
1319                                 printk(KERN_ERR
1320                                        "IP-Config: Reopening network devices...\n");
1321                                 goto try_try_again;
1322                         }
1323
1324                         /* Oh, well.  At least we tried. */
1325                         printk(KERN_ERR "IP-Config: Auto-configuration of network failed.\n");
1326                         return -1;
1327                 }
1328 #else /* !DYNAMIC */
1329                 printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
1330                 ic_close_devs();
1331                 return -1;
1332 #endif /* IPCONFIG_DYNAMIC */
1333         } else {
1334                 /* Device selected manually or only one device -> use it */
1335                 ic_dev = ic_first_dev->dev;
1336         }
1337
1338         addr = root_nfs_parse_addr(root_server_path);
1339         if (root_server_addr == INADDR_NONE)
1340                 root_server_addr = addr;
1341
1342         /*
1343          * Use defaults whereever applicable.
1344          */
1345         if (ic_defaults() < 0)
1346                 return -1;
1347
1348         /*
1349          * Close all network devices except the device we've
1350          * autoconfigured and set up routes.
1351          */
1352         ic_close_devs();
1353         if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1354                 return -1;
1355
1356         /*
1357          * Record which protocol was actually used.
1358          */
1359 #ifdef IPCONFIG_DYNAMIC
1360         ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1361 #endif
1362
1363 #ifndef IPCONFIG_SILENT
1364         /*
1365          * Clue in the operator.
1366          */
1367         printk("IP-Config: Complete:");
1368         printk("\n      device=%s", ic_dev->name);
1369         printk(", addr=%u.%u.%u.%u", NIPQUAD(ic_myaddr));
1370         printk(", mask=%u.%u.%u.%u", NIPQUAD(ic_netmask));
1371         printk(", gw=%u.%u.%u.%u", NIPQUAD(ic_gateway));
1372         printk(",\n     host=%s, domain=%s, nis-domain=%s",
1373                system_utsname.nodename, ic_domain, system_utsname.domainname);
1374         printk(",\n     bootserver=%u.%u.%u.%u", NIPQUAD(ic_servaddr));
1375         printk(", rootserver=%u.%u.%u.%u", NIPQUAD(root_server_addr));
1376         printk(", rootpath=%s", root_server_path);
1377         printk("\n");
1378 #endif /* !SILENT */
1379
1380         return 0;
1381 }
1382
1383 late_initcall(ip_auto_config);
1384
1385
1386 /*
1387  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1388  *  command line parameter. It consists of option fields separated by colons in
1389  *  the following order:
1390  *
1391  *  <client-ip>:<server-ip>:<gw-ip>:<netmask>:<host name>:<device>:<PROTO>
1392  *
1393  *  Any of the fields can be empty which means to use a default value:
1394  *      <client-ip>     - address given by BOOTP or RARP
1395  *      <server-ip>     - address of host returning BOOTP or RARP packet
1396  *      <gw-ip>         - none, or the address returned by BOOTP
1397  *      <netmask>       - automatically determined from <client-ip>, or the
1398  *                        one returned by BOOTP
1399  *      <host name>     - <client-ip> in ASCII notation, or the name returned
1400  *                        by BOOTP
1401  *      <device>        - use all available devices
1402  *      <PROTO>:
1403  *         off|none         - don't do autoconfig at all (DEFAULT)
1404  *         on|any           - use any configured protocol
1405  *         dhcp|bootp|rarp  - use only the specified protocol
1406  *         both             - use both BOOTP and RARP (not DHCP)
1407  */
1408 static int __init ic_proto_name(char *name)
1409 {
1410         if (!strcmp(name, "on") || !strcmp(name, "any")) {
1411                 return 1;
1412         }
1413 #ifdef CONFIG_IP_PNP_DHCP
1414         else if (!strcmp(name, "dhcp")) {
1415                 ic_proto_enabled &= ~IC_RARP;
1416                 return 1;
1417         }
1418 #endif
1419 #ifdef CONFIG_IP_PNP_BOOTP
1420         else if (!strcmp(name, "bootp")) {
1421                 ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1422                 return 1;
1423         }
1424 #endif
1425 #ifdef CONFIG_IP_PNP_RARP
1426         else if (!strcmp(name, "rarp")) {
1427                 ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1428                 return 1;
1429         }
1430 #endif
1431 #ifdef IPCONFIG_DYNAMIC
1432         else if (!strcmp(name, "both")) {
1433                 ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1434                 return 1;
1435         }
1436 #endif
1437         return 0;
1438 }
1439
1440 static int __init ip_auto_config_setup(char *addrs)
1441 {
1442         char *cp, *ip, *dp;
1443         int num = 0;
1444
1445         ic_set_manually = 1;
1446
1447         ic_enable = (*addrs &&
1448                 (strcmp(addrs, "off") != 0) &&
1449                 (strcmp(addrs, "none") != 0));
1450         if (!ic_enable)
1451                 return 1;
1452
1453         if (ic_proto_name(addrs))
1454                 return 1;
1455
1456         /* Parse the whole string */
1457         ip = addrs;
1458         while (ip && *ip) {
1459                 if ((cp = strchr(ip, ':')))
1460                         *cp++ = '\0';
1461                 if (strlen(ip) > 0) {
1462                         DBG(("IP-Config: Parameter #%d: `%s'\n", num, ip));
1463                         switch (num) {
1464                         case 0:
1465                                 if ((ic_myaddr = in_aton(ip)) == INADDR_ANY)
1466                                         ic_myaddr = INADDR_NONE;
1467                                 break;
1468                         case 1:
1469                                 if ((ic_servaddr = in_aton(ip)) == INADDR_ANY)
1470                                         ic_servaddr = INADDR_NONE;
1471                                 break;
1472                         case 2:
1473                                 if ((ic_gateway = in_aton(ip)) == INADDR_ANY)
1474                                         ic_gateway = INADDR_NONE;
1475                                 break;
1476                         case 3:
1477                                 if ((ic_netmask = in_aton(ip)) == INADDR_ANY)
1478                                         ic_netmask = INADDR_NONE;
1479                                 break;
1480                         case 4:
1481                                 if ((dp = strchr(ip, '.'))) {
1482                                         *dp++ = '\0';
1483                                         strlcpy(system_utsname.domainname, dp,
1484                                                 sizeof(system_utsname.domainname));
1485                                 }
1486                                 strlcpy(system_utsname.nodename, ip,
1487                                         sizeof(system_utsname.nodename));
1488                                 ic_host_name_set = 1;
1489                                 break;
1490                         case 5:
1491                                 strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1492                                 break;
1493                         case 6:
1494                                 ic_proto_name(ip);
1495                                 break;
1496                         }
1497                 }
1498                 ip = cp;
1499                 num++;
1500         }
1501
1502         return 1;
1503 }
1504
1505 static int __init nfsaddrs_config_setup(char *addrs)
1506 {
1507         return ip_auto_config_setup(addrs);
1508 }
1509
1510 __setup("ip=", ip_auto_config_setup);
1511 __setup("nfsaddrs=", nfsaddrs_config_setup);