net/ipv4/ipconfig.c

   1 /*
   2  *  $Id: ipconfig.c,v 1.20 1999/03/28 10:18:28 davem Exp $
   3  *
   4  *  Automatic Configuration of IP -- use BOOTP or RARP or user-supplied
   5  *  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
  17 #include <linux/config.h>
  18 #include <linux/types.h>
  19 #include <linux/string.h>
  20 #include <linux/kernel.h>
  21 #include <linux/sched.h>
  22 #include <linux/random.h>
  23 #include <linux/init.h>
  24 #include <linux/utsname.h>
  25 #include <linux/in.h>
  26 #include <linux/if.h>
  27 #include <linux/inet.h>
  28 #include <linux/netdevice.h>
  29 #include <linux/if_arp.h>
  30 #include <linux/skbuff.h>
  31 #include <linux/ip.h>
  32 #include <linux/socket.h>
  33 #include <linux/route.h>
  34 #include <linux/udp.h>
  35 #include <net/arp.h>
  36 #include <net/ip.h>
  37 #include <net/ipconfig.h>
  38
  39 #include <asm/segment.h>
  40 #include <asm/uaccess.h>
  41 #include <asm/checksum.h>
  42
  43 /* Define this to allow debugging output */
  44 #undef IPCONFIG_DEBUG
  45
  46 #ifdef IPCONFIG_DEBUG
  47 #define DBG(x) printk x
  48 #else
  49 #define DBG(x) do { } while(0)
  50 #endif
  51
  52 /* Define the timeout for waiting for a RARP/BOOTP reply */
  53 #define CONF_BASE_TIMEOUT       (HZ*5)  /* Initial timeout: 5 seconds */
  54 #define CONF_RETRIES            10      /* 10 retries */
  55 #define CONF_TIMEOUT_RANDOM     (HZ)    /* Maximum amount of randomization */
  56 #define CONF_TIMEOUT_MULT       *5/4    /* Rate of timeout growth */
  57 #define CONF_TIMEOUT_MAX        (HZ*30) /* Maximum allowed timeout */
  58
  59 /* IP configuration */
  60 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };/* Name of user-selected boot device */
  61 u32 ic_myaddr __initdata = INADDR_NONE;         /* My IP address */
  62 u32 ic_servaddr __initdata = INADDR_NONE;       /* Server IP address */
  63 u32 ic_gateway __initdata = INADDR_NONE;        /* Gateway IP address */
  64 u32 ic_netmask __initdata = INADDR_NONE;        /* Netmask for local subnet */
  65 int ic_enable __initdata = 1;                   /* Automatic IP configuration enabled */
  66 int ic_host_name_set __initdata = 0;            /* Host name configured manually */
  67 int ic_set_manually __initdata = 0;             /* IPconfig parameters set manually */
  68
  69 u32 root_server_addr __initdata = INADDR_NONE;          /* Address of boot server */
  70 u8 root_server_path[256] __initdata = { 0, };           /* Path to mount as root */
  71
  72 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_RARP)
  73
  74 #define CONFIG_IP_PNP_DYNAMIC
  75
  76 static int ic_proto_enabled __initdata = 0                      /* Protocols enabled */
  77 #ifdef CONFIG_IP_PNP_BOOTP
  78                         | IC_BOOTP
  79 #endif
  80 #ifdef CONFIG_IP_PNP_RARP
  81                         | IC_RARP
  82 #endif
  83                         ;
  84 static int ic_got_reply __initdata = 0;                         /* Protocol(s) we got reply from */
  85
  86 #else
  87
  88 static int ic_proto_enabled __initdata = 0;
  89
  90 #endif
  91
  92 static int ic_proto_have_if __initdata = 0;
  93
  94 /*
  95  *      Network devices
  96  */
  97
  98 struct ic_device {
  99         struct ic_device *next;
 100         struct device *dev;
 101         unsigned short flags;
 102         int able;
 103 };
 104
 105 static struct ic_device *ic_first_dev __initdata = NULL;/* List of open device */
 106 static struct device *ic_dev __initdata = NULL;         /* Selected device */
 107
 108 static int __init ic_open_devs(void)
 109 {
 110         struct ic_device *d, **last;
 111         struct device *dev;
 112         unsigned short oflags;
 113
 114         last = &ic_first_dev;
 115         for (dev = dev_base; dev; dev = dev->next)
 116                 if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
 117                     (!(dev->flags & IFF_LOOPBACK) &&
 118                      (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
 119                      strncmp(dev->name, "dummy", 5))) {
 120                         int able = 0;
 121                         if (dev->mtu >= 364)
 122                                 able |= IC_BOOTP;
 123                         else
 124                                 printk(KERN_WARNING "BOOTP: Ignoring device %s, MTU %d too small", dev->name, dev->mtu);
 125                         if (!(dev->flags & IFF_NOARP))
 126                                 able |= IC_RARP;
 127                         able &= ic_proto_enabled;
 128                         if (ic_proto_enabled && !able)
 129                                 continue;
 130                         oflags = dev->flags;
 131                         if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
 132                                 printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
 133                                 continue;
 134                         }
 135                         if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL)))
 136                                 return -1;
 137                         d->dev = dev;
 138                         *last = d;
 139                         last = &d->next;
 140                         d->flags = oflags;
 141                         d->able = able;
 142                         ic_proto_have_if |= able;
 143                         DBG(("IP-Config: Opened %s (able=%d)\n", dev->name, able));
 144                 }
 145         *last = NULL;
 146
 147         if (!ic_first_dev) {
 148                 if (user_dev_name[0])
 149                         printk(KERN_ERR "IP-Config: Device `%s' not found.\n", user_dev_name);
 150                 else
 151                         printk(KERN_ERR "IP-Config: No network devices available.\n");
 152                 return -1;
 153         }
 154         return 0;
 155 }
 156
 157 static void __init ic_close_devs(void)
 158 {
 159         struct ic_device *d, *next;
 160         struct device *dev;
 161
 162         next = ic_first_dev;
 163         while ((d = next)) {
 164                 next = d->next;
 165                 dev = d->dev;
 166                 if (dev != ic_dev) {
 167                         DBG(("IP-Config: Downing %s\n", dev->name));
 168                         dev_change_flags(dev, d->flags);
 169                 }
 170                 kfree_s(d, sizeof(struct ic_device));
 171         }
 172 }
 173
 174 /*
 175  *      Interface to various network functions.
 176  */
 177
 178 static inline void
 179 set_sockaddr(struct sockaddr_in *sin, u32 addr, u16 port)
 180 {
 181         sin->sin_family = AF_INET;
 182         sin->sin_addr.s_addr = addr;
 183         sin->sin_port = port;
 184 }
 185
 186 static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
 187 {
 188         int res;
 189
 190         mm_segment_t oldfs = get_fs();
 191         set_fs(get_ds());
 192         res = devinet_ioctl(cmd, arg);
 193         set_fs(oldfs);
 194         return res;
 195 }
 196
 197 static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg)
 198 {
 199         int res;
 200
 201         mm_segment_t oldfs = get_fs();
 202         set_fs(get_ds());
 203         res = ip_rt_ioctl(cmd, arg);
 204         set_fs(oldfs);
 205         return res;
 206 }
 207
 208 /*
 209  *      Set up interface addresses and routes.
 210  */
 211
 212 static int __init ic_setup_if(void)
 213 {
 214         struct ifreq ir;
 215         struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
 216         int err;
 217
 218         memset(&ir, 0, sizeof(ir));
 219         strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->name);
 220         set_sockaddr(sin, ic_myaddr, 0);
 221         if ((err = ic_dev_ioctl(SIOCSIFADDR, &ir)) < 0) {
 222                 printk(KERN_ERR "IP-Config: Unable to set interface address (%d).\n", err);
 223                 return -1;
 224         }
 225         set_sockaddr(sin, ic_netmask, 0);
 226         if ((err = ic_dev_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
 227                 printk(KERN_ERR "IP-Config: Unable to set interface netmask (%d).\n", err);
 228                 return -1;
 229         }
 230         set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
 231         if ((err = ic_dev_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
 232                 printk(KERN_ERR "IP-Config: Unable to set interface broadcast address (%d).\n", err);
 233                 return -1;
 234         }
 235         return 0;
 236 }
 237
 238 static int __init ic_setup_routes(void)
 239 {
 240         /* No need to setup device routes, only the default route... */
 241
 242         if (ic_gateway != INADDR_NONE) {
 243                 struct rtentry rm;
 244                 int err;
 245
 246                 memset(&rm, 0, sizeof(rm));
 247                 if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
 248                         printk(KERN_ERR "IP-Config: Gateway not on directly connected network.\n");
 249                         return -1;
 250                 }
 251                 set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
 252                 set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
 253                 set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
 254                 rm.rt_flags = RTF_UP | RTF_GATEWAY;
 255                 if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) {
 256                         printk(KERN_ERR "IP-Config: Cannot add default route (%d).\n", err);
 257                         return -1;
 258                 }
 259         }
 260
 261         return 0;
 262 }
 263
 264 /*
 265  *      Fill in default values for all missing parameters.
 266  */
 267
 268 static int __init ic_defaults(void)
 269 {
 270         /*
 271          *      At this point we have no userspace running so need not
 272          *      claim locks on system_utsname
 273          */
 274
 275         if (!ic_host_name_set)
 276                 strcpy(system_utsname.nodename, in_ntoa(ic_myaddr));
 277
 278         if (root_server_addr == INADDR_NONE)
 279                 root_server_addr = ic_servaddr;
 280
 281         if (ic_netmask == INADDR_NONE) {
 282                 if (IN_CLASSA(ntohl(ic_myaddr)))
 283                         ic_netmask = htonl(IN_CLASSA_NET);
 284                 else if (IN_CLASSB(ntohl(ic_myaddr)))
 285                         ic_netmask = htonl(IN_CLASSB_NET);
 286                 else if (IN_CLASSC(ntohl(ic_myaddr)))
 287                         ic_netmask = htonl(IN_CLASSC_NET);
 288                 else {
 289                         printk(KERN_ERR "IP-Config: Unable to guess netmask for address %08x\n", ic_myaddr);
 290                         return -1;
 291                 }
 292                 printk("IP-Config: Guessing netmask %s\n", in_ntoa(ic_netmask));
 293         }
 294
 295         return 0;
 296 }
 297
 298 /*
 299  *      RARP support.
 300  */
 301
 302 #ifdef CONFIG_IP_PNP_RARP
 303
 304 static int ic_rarp_recv(struct sk_buff *skb, struct device *dev, struct packet_type *pt);
 305
 306 static struct packet_type rarp_packet_type __initdata = {
 307         __constant_htons(ETH_P_RARP),
 308         NULL,                   /* Listen to all devices */
 309         ic_rarp_recv,
 310         NULL,
 311         NULL
 312 };
 313
 314 static inline void ic_rarp_init(void)
 315 {
 316         dev_add_pack(&rarp_packet_type);
 317 }
 318
 319 static inline void ic_rarp_cleanup(void)
 320 {
 321         dev_remove_pack(&rarp_packet_type);
 322 }
 323
 324 /*
 325  *  Process received RARP packet.
 326  */
 327 static int __init
 328 ic_rarp_recv(struct sk_buff *skb, struct device *dev, struct packet_type *pt)
 329 {
 330         struct arphdr *rarp = (struct arphdr *)skb->h.raw;
 331         unsigned char *rarp_ptr = (unsigned char *) (rarp + 1);
 332         unsigned long sip, tip;
 333         unsigned char *sha, *tha;               /* s for "source", t for "target" */
 334
 335         /* If we already have a reply, just drop the packet */
 336         if (ic_got_reply)
 337                 goto drop;
 338
 339         /* If this test doesn't pass, it's not IP, or we should ignore it anyway */
 340         if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
 341                 goto drop;
 342
 343         /* If it's not a RARP reply, delete it. */
 344         if (rarp->ar_op != htons(ARPOP_RREPLY))
 345                 goto drop;
 346
 347         /* If it's not Ethernet, delete it. */
 348         if (rarp->ar_pro != htons(ETH_P_IP))
 349                 goto drop;
 350
 351         /* Extract variable-width fields */
 352         sha = rarp_ptr;
 353         rarp_ptr += dev->addr_len;
 354         memcpy(&sip, rarp_ptr, 4);
 355         rarp_ptr += 4;
 356         tha = rarp_ptr;
 357         rarp_ptr += dev->addr_len;
 358         memcpy(&tip, rarp_ptr, 4);
 359
 360         /* Discard packets which are not meant for us. */
 361         if (memcmp(tha, dev->dev_addr, dev->addr_len))
 362                 goto drop;
 363
 364         /* Discard packets which are not from specified server. */
 365         if (ic_servaddr != INADDR_NONE && ic_servaddr != sip)
 366                 goto drop;
 367
 368         /* Victory! The packet is what we were looking for! */
 369         if (!ic_got_reply) {
 370                 ic_got_reply = IC_RARP;
 371                 ic_dev = dev;
 372                 if (ic_myaddr == INADDR_NONE)
 373                         ic_myaddr = tip;
 374                 ic_servaddr = sip;
 375         }
 376
 377         /* And throw the packet out... */
 378 drop:
 379         kfree_skb(skb);
 380         return 0;
 381 }
 382
 383
 384 /*
 385  *  Send RARP request packet over all devices which allow RARP.
 386  */
 387 static void __init ic_rarp_send(void)
 388 {
 389         struct ic_device *d;
 390
 391         for (d=ic_first_dev; d; d=d->next)
 392                 if (d->able & IC_RARP) {
 393                         struct device *dev = d->dev;
 394                         arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
 395                                  dev->dev_addr, dev->dev_addr);
 396                 }
 397 }
 398
 399 #endif
 400
 401 /*
 402  *      BOOTP support.
 403  */
 404
 405 #ifdef CONFIG_IP_PNP_BOOTP
 406
 407 struct bootp_pkt {              /* BOOTP packet format */
 408         struct iphdr iph;       /* IP header */
 409         struct udphdr udph;     /* UDP header */
 410         u8 op;                  /* 1=request, 2=reply */
 411         u8 htype;               /* HW address type */
 412         u8 hlen;                /* HW address length */
 413         u8 hops;                /* Used only by gateways */
 414         u32 xid;                /* Transaction ID */
 415         u16 secs;               /* Seconds since we started */
 416         u16 flags;              /* Just what it says */
 417         u32 client_ip;          /* Client's IP address if known */
 418         u32 your_ip;            /* Assigned IP address */
 419         u32 server_ip;          /* Server's IP address */
 420         u32 relay_ip;           /* IP address of BOOTP relay */
 421         u8 hw_addr[16];         /* Client's HW address */
 422         u8 serv_name[64];       /* Server host name */
 423         u8 boot_file[128];      /* Name of boot file */
 424         u8 vendor_area[128];    /* Area for extensions */
 425 };
 426
 427 #define BOOTP_REQUEST 1
 428 #define BOOTP_REPLY 2
 429
 430 static u32 ic_bootp_xid;
 431
 432 static int ic_bootp_recv(struct sk_buff *skb, struct device *dev, struct packet_type *pt);
 433
 434 static struct packet_type bootp_packet_type __initdata = {
 435         __constant_htons(ETH_P_IP),
 436         NULL,                   /* Listen to all devices */
 437         ic_bootp_recv,
 438         NULL,
 439         NULL
 440 };
 441
 442
 443 /*
 444  *  Initialize BOOTP extension fields in the request.
 445  */
 446 static void __init ic_bootp_init_ext(u8 *e)
 447 {
 448         *e++ = 99;              /* RFC1048 Magic Cookie */
 449         *e++ = 130;
 450         *e++ = 83;
 451         *e++ = 99;
 452         *e++ = 1;               /* Subnet mask request */
 453         *e++ = 4;
 454         e += 4;
 455         *e++ = 3;               /* Default gateway request */
 456         *e++ = 4;
 457         e += 4;
 458         *e++ = 12;              /* Host name request */
 459         *e++ = 32;
 460         e += 32;
 461         *e++ = 40;              /* NIS Domain name request */
 462         *e++ = 32;
 463         e += 32;
 464         *e++ = 17;              /* Boot path */
 465         *e++ = 32;
 466         e += 32;
 467         *e = 255;               /* End of the list */
 468 }
 469
 470
 471 /*
 472  *  Initialize the BOOTP mechanism.
 473  */
 474 static inline void ic_bootp_init(void)
 475 {
 476         get_random_bytes(&ic_bootp_xid, sizeof(u32));
 477         DBG(("BOOTP: XID=%08x\n", ic_bootp_xid));
 478         dev_add_pack(&bootp_packet_type);
 479 }
 480
 481
 482 /*
 483  *  BOOTP cleanup.
 484  */
 485 static inline void ic_bootp_cleanup(void)
 486 {
 487         dev_remove_pack(&bootp_packet_type);
 488 }
 489
 490
 491 /*
 492  *  Send BOOTP request to single interface.
 493  */
 494 static void __init ic_bootp_send_if(struct ic_device *d, u32 jiffies)
 495 {
 496         struct device *dev = d->dev;
 497         struct sk_buff *skb;
 498         struct bootp_pkt *b;
 499         int hh_len = (dev->hard_header_len + 15) & ~15;
 500         struct iphdr *h;
 501
 502         /* Allocate packet */
 503         skb = alloc_skb(sizeof(struct bootp_pkt) + hh_len + 15, GFP_KERNEL);
 504         if (!skb)
 505                 return;
 506         skb_reserve(skb, hh_len);
 507         b = (struct bootp_pkt *) skb_put(skb, sizeof(struct bootp_pkt));
 508         memset(b, 0, sizeof(struct bootp_pkt));
 509
 510         /* Construct IP header */
 511         skb->nh.iph = h = &b->iph;
 512         h->version = 4;
 513         h->ihl = 5;
 514         h->tot_len = htons(sizeof(struct bootp_pkt));
 515         h->frag_off = htons(IP_DF);
 516         h->ttl = 64;
 517         h->protocol = IPPROTO_UDP;
 518         h->daddr = INADDR_BROADCAST;
 519         h->check = ip_fast_csum((unsigned char *) h, h->ihl);
 520
 521         /* Construct UDP header */
 522         b->udph.source = htons(68);
 523         b->udph.dest = htons(67);
 524         b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
 525         /* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
 526
 527         /* Construct BOOTP header */
 528         b->op = BOOTP_REQUEST;
 529         b->htype = dev->type;
 530         b->hlen = dev->addr_len;
 531         memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
 532         b->secs = htons(jiffies / HZ);
 533         b->xid = ic_bootp_xid;
 534         ic_bootp_init_ext(b->vendor_area);
 535
 536         /* Chain packet down the line... */
 537         skb->dev = dev;
 538         skb->protocol = __constant_htons(ETH_P_IP);
 539         if ((dev->hard_header &&
 540              dev->hard_header(skb, dev, ntohs(skb->protocol), dev->broadcast, dev->dev_addr, skb->len) < 0) ||
 541             dev_queue_xmit(skb) < 0)
 542                 printk("E");
 543 }
 544
 545
 546 /*
 547  *  Send BOOTP requests to all interfaces.
 548  */
 549 static void __init ic_bootp_send(u32 jiffies)
 550 {
 551         struct ic_device *d;
 552
 553         for(d=ic_first_dev; d; d=d->next)
 554                 if (d->able & IC_BOOTP)
 555                         ic_bootp_send_if(d, jiffies);
 556 }
 557
 558
 559 /*
 560  *  Copy BOOTP-supplied string if not already set.
 561  */
 562 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
 563 {
 564         if (!len)
 565                 return 0;
 566         if (len > max-1)
 567                 len = max-1;
 568         strncpy(dest, src, len);
 569         dest[len] = '\0';
 570         return 1;
 571 }
 572
 573
 574 /*
 575  *  Process BOOTP extension.
 576  */
 577 static void __init ic_do_bootp_ext(u8 *ext)
 578 {
 579 #ifdef IPCONFIG_DEBUG
 580         u8 *c;
 581
 582         printk("BOOTP: Got extension %02x",*ext);
 583         for(c=ext+2; c<ext+2+ext[1]; c++)
 584                 printk(" %02x", *c);
 585         printk("\n");
 586 #endif
 587
 588         switch (*ext++) {
 589                 case 1:         /* Subnet mask */
 590                         if (ic_netmask == INADDR_NONE)
 591                                 memcpy(&ic_netmask, ext+1, 4);
 592                         break;
 593                 case 3:         /* Default gateway */
 594                         if (ic_gateway == INADDR_NONE)
 595                                 memcpy(&ic_gateway, ext+1, 4);
 596                         break;
 597                 case 12:        /* Host name */
 598                         ic_bootp_string(system_utsname.nodename, ext+1, *ext, __NEW_UTS_LEN);
 599                         ic_host_name_set = 1;
 600                         break;
 601                 case 40:        /* NIS Domain name */
 602                         ic_bootp_string(system_utsname.domainname, ext+1, *ext, __NEW_UTS_LEN);
 603                         break;
 604                 case 17:        /* Root path */
 605                         if (!root_server_path[0])
 606                                 ic_bootp_string(root_server_path, ext+1, *ext, sizeof(root_server_path));
 607                         break;
 608         }
 609 }
 610
 611
 612 /*
 613  *  Receive BOOTP reply.
 614  */
 615 static int __init ic_bootp_recv(struct sk_buff *skb, struct device *dev, struct packet_type *pt)
 616 {
 617         struct bootp_pkt *b = (struct bootp_pkt *) skb->nh.iph;
 618         struct iphdr *h = &b->iph;
 619         int len;
 620
 621         /* If we already have a reply, just drop the packet */
 622         if (ic_got_reply)
 623                 goto drop;
 624
 625         /* Check whether it's a BOOTP packet */
 626         if (skb->pkt_type == PACKET_OTHERHOST ||
 627             skb->len < sizeof(struct udphdr) + sizeof(struct iphdr) ||
 628             h->ihl != 5 ||
 629             h->version != 4 ||
 630             ip_fast_csum((char *) h, h->ihl) != 0 ||
 631             skb->len < ntohs(h->tot_len) ||
 632             h->protocol != IPPROTO_UDP ||
 633             b->udph.source != htons(67) ||
 634             b->udph.dest != htons(68) ||
 635             ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
 636                 goto drop;
 637
 638         /* Fragments are not supported */
 639         if (h->frag_off & htons(IP_OFFSET|IP_MF)) {
 640                 printk(KERN_ERR "BOOTP: Ignoring fragmented reply.\n");
 641                 goto drop;
 642         }
 643
 644         /* Is it a reply to our BOOTP request? */
 645         len = ntohs(b->udph.len) - sizeof(struct udphdr);
 646         if (len < 300 ||                                    /* See RFC 951:2.1 */
 647             b->op != BOOTP_REPLY ||
 648             b->xid != ic_bootp_xid) {
 649                 printk("?");
 650                 goto drop;
 651         }
 652
 653         /* Extract basic fields */
 654         ic_myaddr = b->your_ip;
 655         ic_servaddr = b->server_ip;
 656         ic_got_reply = IC_BOOTP;
 657         ic_dev = dev;
 658
 659         /* Parse extensions */
 660         if (b->vendor_area[0] == 99 &&  /* Check magic cookie */
 661             b->vendor_area[1] == 130 &&
 662             b->vendor_area[2] == 83 &&
 663             b->vendor_area[3] == 99) {
 664                 u8 *ext = &b->vendor_area[4];
 665                 u8 *end = (u8 *) b + len;
 666                 while (ext < end && *ext != 0xff) {
 667                         if (*ext == 0)          /* Padding */
 668                                 ext++;
 669                         else {
 670                                 u8 *opt = ext;
 671                                 ext += ext[1] + 2;
 672                                 if (ext <= end)
 673                                         ic_do_bootp_ext(opt);
 674                         }
 675                 }
 676         }
 677
 678         if (ic_gateway == INADDR_NONE && b->relay_ip)
 679                 ic_gateway = b->relay_ip;
 680
 681 drop:
 682         kfree_skb(skb);
 683         return 0;
 684 }
 685
 686
 687 #endif
 688
 689
 690 /*
 691  *      Dynamic IP configuration -- BOOTP and RARP.
 692  */
 693
 694 #ifdef CONFIG_IP_PNP_DYNAMIC
 695
 696 static int __init ic_dynamic(void)
 697 {
 698         int retries;
 699         unsigned long timeout, jiff;
 700         unsigned long start_jiffies;
 701         int do_rarp = ic_proto_have_if & IC_RARP;
 702         int do_bootp = ic_proto_have_if & IC_BOOTP;
 703
 704         /*
 705          * If neither BOOTP nor RARP was selected, return with an error. This
 706          * routine gets only called when some pieces of information are mis-
 707          * sing, and without BOOTP and RARP we are not able to get that in-
 708          * formation.
 709          */
 710         if (!ic_proto_enabled) {
 711                 printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
 712                 return -1;
 713         }
 714
 715 #ifdef CONFIG_IP_PNP_BOOTP
 716         if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
 717                 printk(KERN_ERR "BOOTP: No suitable device found.\n");
 718 #endif
 719
 720 #ifdef CONFIG_IP_PNP_RARP
 721         if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
 722                 printk(KERN_ERR "RARP: No suitable device found.\n");
 723 #endif
 724
 725         if (!ic_proto_have_if)
 726                 /* Error message already printed */
 727                 return -1;
 728
 729         /*
 730          * Setup RARP and BOOTP protocols
 731          */
 732 #ifdef CONFIG_IP_PNP_RARP
 733         if (do_rarp)
 734                 ic_rarp_init();
 735 #endif
 736 #ifdef CONFIG_IP_PNP_BOOTP
 737         if (do_bootp)
 738                 ic_bootp_init();
 739 #endif
 740
 741         /*
 742          * Send requests and wait, until we get an answer. This loop
 743          * seems to be a terrible waste of CPU time, but actually there is
 744          * only one process running at all, so we don't need to use any
 745          * scheduler functions.
 746          * [Actually we could now, but the nothing else running note still
 747          *  applies.. - AC]
 748          */
 749         printk(KERN_NOTICE "Sending %s%s%s requests...",
 750                 do_bootp ? "BOOTP" : "",
 751                 do_bootp && do_rarp ? " and " : "",
 752                 do_rarp ? "RARP" : "");
 753         start_jiffies = jiffies;
 754         retries = CONF_RETRIES;
 755         get_random_bytes(&timeout, sizeof(timeout));
 756         timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned) CONF_TIMEOUT_RANDOM);
 757         for(;;) {
 758 #ifdef CONFIG_IP_PNP_BOOTP
 759                 if (do_bootp)
 760                         ic_bootp_send(jiffies - start_jiffies);
 761 #endif
 762 #ifdef CONFIG_IP_PNP_RARP
 763                 if (do_rarp)
 764                         ic_rarp_send();
 765 #endif
 766                 printk(".");
 767                 jiff = jiffies + timeout;
 768                 while (jiffies < jiff && !ic_got_reply)
 769                         ;
 770                 if (ic_got_reply) {
 771                         printk(" OK\n");
 772                         break;
 773                 }
 774                 if (! --retries) {
 775                         printk(" timed out!\n");
 776                         break;
 777                 }
 778                 timeout = timeout CONF_TIMEOUT_MULT;
 779                 if (timeout > CONF_TIMEOUT_MAX)
 780                         timeout = CONF_TIMEOUT_MAX;
 781         }
 782
 783 #ifdef CONFIG_IP_PNP_RARP
 784         if (do_rarp)
 785                 ic_rarp_cleanup();
 786 #endif
 787 #ifdef CONFIG_IP_PNP_BOOTP
 788         if (do_bootp)
 789                 ic_bootp_cleanup();
 790 #endif
 791
 792         if (!ic_got_reply)
 793                 return -1;
 794
 795         printk("IP-Config: Got %s answer from %s, ",
 796                 (ic_got_reply & IC_BOOTP) ? "BOOTP" : "RARP",
 797                 in_ntoa(ic_servaddr));
 798         printk("my address is %s\n", in_ntoa(ic_myaddr));
 799
 800         return 0;
 801 }
 802
 803 #endif
 804
 805 /*
 806  *      IP Autoconfig dispatcher.
 807  */
 808
 809 int __init ip_auto_config(void)
 810 {
 811         if (!ic_enable)
 812                 return 0;
 813
 814         DBG(("IP-Config: Entered.\n"));
 815
 816         /* Setup all network devices */
 817         if (ic_open_devs() < 0)
 818                 return -1;
 819
 820         /*
 821          * If the config information is insufficient (e.g., our IP address or
 822          * IP address of the boot server is missing or we have multiple network
 823          * interfaces and no default was set), use BOOTP or RARP to get the
 824          * missing values.
 825          */
 826         if (ic_myaddr == INADDR_NONE ||
 827 #ifdef CONFIG_ROOT_NFS
 828             (root_server_addr == INADDR_NONE && ic_servaddr == INADDR_NONE) ||
 829 #endif
 830             ic_first_dev->next) {
 831 #ifdef CONFIG_IP_PNP_DYNAMIC
 832                 if (ic_dynamic() < 0) {
 833                         printk(KERN_ERR "IP-Config: Auto-configuration of network failed.\n");
 834                         ic_close_devs();
 835                         return -1;
 836                 }
 837 #else
 838                 printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
 839                 ic_close_devs();
 840                 return -1;
 841 #endif
 842         } else {
 843                 ic_dev = ic_first_dev->dev;     /* Device selected manually or only one device -> use it */
 844         }
 845
 846         /*
 847          * Use defaults whereever applicable.
 848          */
 849         if (ic_defaults() < 0)
 850                 return -1;
 851
 852         /*
 853          * Close all network devices except the device we've
 854          * autoconfigured and set up routes.
 855          */
 856         ic_close_devs();
 857         if (ic_setup_if() < 0 || ic_setup_routes() < 0)
 858                 return -1;
 859
 860         DBG(("IP-Config: device=%s, local=%08x, server=%08x, boot=%08x, gw=%08x, mask=%08x\n",
 861             ic_dev->name, ic_myaddr, ic_servaddr, root_server_addr, ic_gateway, ic_netmask));
 862         DBG(("IP-Config: host=%s, domain=%s, path=`%s'\n", system_utsname.nodename,
 863             system_utsname.domainname, root_server_path));
 864         return 0;
 865 }
 866
 867 /*
 868  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
 869  *  command line parameter. It consists of option fields separated by colons in
 870  *  the following order:
 871  *
 872  *  <client-ip>:<server-ip>:<gw-ip>:<netmask>:<host name>:<device>:<bootp|rarp>
 873  *
 874  *  Any of the fields can be empty which means to use a default value:
 875  *      <client-ip>     - address given by BOOTP or RARP
 876  *      <server-ip>     - address of host returning BOOTP or RARP packet
 877  *      <gw-ip>         - none, or the address returned by BOOTP
 878  *      <netmask>       - automatically determined from <client-ip>, or the
 879  *                        one returned by BOOTP
 880  *      <host name>     - <client-ip> in ASCII notation, or the name returned
 881  *                        by BOOTP
 882  *      <device>        - use all available devices
 883  *      <bootp|rarp|both|off> - use both protocols to determine my own address
 884  */
 885 static int __init ic_proto_name(char *name)
 886 {
 887         if (!strcmp(name, "off")) {
 888                 ic_proto_enabled = 0;
 889                 return 1;
 890         }
 891 #ifdef CONFIG_IP_PNP_BOOTP
 892         else if (!strcmp(name, "bootp")) {
 893                 ic_proto_enabled &= ~IC_RARP;
 894                 return 1;
 895         }
 896 #endif
 897 #ifdef CONFIG_IP_PNP_RARP
 898         else if (!strcmp(name, "rarp")) {
 899                 ic_proto_enabled &= ~IC_BOOTP;
 900                 return 1;
 901         }
 902 #endif
 903 #ifdef CONFIG_IP_PNP_DYNAMIC
 904         else if (!strcmp(name, "both")) {
 905                 return 1;
 906         }
 907 #endif
 908         return 0;
 909 }
 910
 911 void __init ip_auto_config_setup(char *addrs, int *ints)
 912 {
 913         char *cp, *ip, *dp;
 914         int num = 0;
 915
 916         ic_set_manually = 1;
 917         if (!strcmp(addrs, "off")) {
 918                 ic_enable = 0;
 919                 return;
 920         }
 921         if (ic_proto_name(addrs))
 922                 return;
 923
 924         /* Parse the whole string */
 925         ip = addrs;
 926         while (ip && *ip) {
 927                 if ((cp = strchr(ip, ':')))
 928                         *cp++ = '\0';
 929                 if (strlen(ip) > 0) {
 930                         DBG(("IP-Config: Parameter #%d: `%s'\n", num, ip));
 931                         switch (num) {
 932                         case 0:
 933                                 if ((ic_myaddr = in_aton(ip)) == INADDR_ANY)
 934                                         ic_myaddr = INADDR_NONE;
 935                                 break;
 936                         case 1:
 937                                 if ((ic_servaddr = in_aton(ip)) == INADDR_ANY)
 938                                         ic_servaddr = INADDR_NONE;
 939                                 break;
 940                         case 2:
 941                                 if ((ic_gateway = in_aton(ip)) == INADDR_ANY)
 942                                         ic_gateway = INADDR_NONE;
 943                                 break;
 944                         case 3:
 945                                 if ((ic_netmask = in_aton(ip)) == INADDR_ANY)
 946                                         ic_netmask = INADDR_NONE;
 947                                 break;
 948                         case 4:
 949                                 if ((dp = strchr(ip, '.'))) {
 950                                         *dp++ = '\0';
 951                                         strncpy(system_utsname.domainname, dp, __NEW_UTS_LEN);
 952                                         system_utsname.domainname[__NEW_UTS_LEN] = '\0';
 953                                 }
 954                                 strncpy(system_utsname.nodename, ip, __NEW_UTS_LEN);
 955                                 system_utsname.nodename[__NEW_UTS_LEN] = '\0';
 956                                 ic_host_name_set = 1;
 957                                 break;
 958                         case 5:
 959                                 strncpy(user_dev_name, ip, IFNAMSIZ);
 960                                 user_dev_name[IFNAMSIZ-1] = '\0';
 961                                 break;
 962                         case 6:
 963                                 ic_proto_name(ip);
 964                                 break;
 965                         }
 966                 }
 967                 ip = cp;
 968                 num++;
 969         }
 970 }