net/ipv4/ipconfig.c

   1 /*
   2  *  $Id: ipconfig.c,v 1.33 2000/06/21 17:21:43 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  *  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
  21 #include <linux/config.h>
  22 #include <linux/types.h>
  23 #include <linux/string.h>
  24 #include <linux/kernel.h>
  25 #include <linux/sched.h>
  26 #include <linux/random.h>
  27 #include <linux/init.h>
  28 #include <linux/utsname.h>
  29 #include <linux/in.h>
  30 #include <linux/if.h>
  31 #include <linux/inet.h>
  32 #include <linux/netdevice.h>
  33 #include <linux/if_arp.h>
  34 #include <linux/skbuff.h>
  35 #include <linux/ip.h>
  36 #include <linux/socket.h>
  37 #include <linux/route.h>
  38 #include <linux/udp.h>
  39 #include <net/arp.h>
  40 #include <net/ip.h>
  41 #include <net/ipconfig.h>
  42
  43 #include <asm/uaccess.h>
  44 #include <asm/checksum.h>
  45
  46 /* Define this to allow debugging output */
  47 #undef IPCONFIG_DEBUG
  48
  49 #ifdef IPCONFIG_DEBUG
  50 #define DBG(x) printk x
  51 #else
  52 #define DBG(x) do { } while(0)
  53 #endif
  54
  55 /* Define the timeout for waiting for a RARP/BOOTP reply */
  56 #define CONF_BASE_TIMEOUT       (HZ*5)  /* Initial timeout: 5 seconds */
  57 #define CONF_RETRIES            10      /* 10 retries */
  58 #define CONF_TIMEOUT_RANDOM     (HZ)    /* Maximum amount of randomization */
  59 #define CONF_TIMEOUT_MULT       *5/4    /* Rate of timeout growth */
  60 #define CONF_TIMEOUT_MAX        (HZ*30) /* Maximum allowed timeout */
  61
  62 /* IP configuration */
  63 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };/* Name of user-selected boot device */
  64 u32 ic_myaddr __initdata = INADDR_NONE;         /* My IP address */
  65 u32 ic_servaddr __initdata = INADDR_NONE;       /* Server IP address */
  66 u32 ic_gateway __initdata = INADDR_NONE;        /* Gateway IP address */
  67 u32 ic_netmask __initdata = INADDR_NONE;        /* Netmask for local subnet */
  68 int ic_enable __initdata = 1;                   /* Automatic IP configuration enabled */
  69 int ic_host_name_set __initdata = 0;            /* Host name configured manually */
  70 int ic_set_manually __initdata = 0;             /* IPconfig parameters set manually */
  71
  72 u32 root_server_addr __initdata = INADDR_NONE;          /* Address of boot server */
  73 u8 root_server_path[256] __initdata = { 0, };           /* Path to mount as root */
  74
  75 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_RARP)
  76
  77 #define CONFIG_IP_PNP_DYNAMIC
  78
  79 int ic_proto_enabled __initdata = 0                     /* Protocols enabled */
  80 #ifdef CONFIG_IP_PNP_BOOTP
  81                         | IC_BOOTP
  82 #endif
  83 #ifdef CONFIG_IP_PNP_RARP
  84                         | IC_RARP
  85 #endif
  86                         ;
  87 static int ic_got_reply __initdata = 0;                         /* Protocol(s) we got reply from */
  88
  89 #else
  90
  91 static int ic_proto_enabled __initdata = 0;
  92
  93 #endif
  94
  95 static int ic_proto_have_if __initdata = 0;
  96
  97 /*
  98  *      Network devices
  99  */
 100
 101 struct ic_device {
 102         struct ic_device *next;
 103         struct net_device *dev;
 104         unsigned short flags;
 105         int able;
 106 };
 107
 108 static struct ic_device *ic_first_dev __initdata = NULL;/* List of open device */
 109 static struct net_device *ic_dev __initdata = NULL;             /* Selected device */
 110
 111 static int __init ic_open_devs(void)
 112 {
 113         struct ic_device *d, **last;
 114         struct net_device *dev;
 115         unsigned short oflags;
 116
 117         last = &ic_first_dev;
 118         rtnl_shlock();
 119         for (dev = dev_base; dev; dev = dev->next) {
 120                 if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
 121                     (!(dev->flags & IFF_LOOPBACK) &&
 122                      (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
 123                      strncmp(dev->name, "dummy", 5))) {
 124                         int able = 0;
 125                         if (dev->mtu >= 364)
 126                                 able |= IC_BOOTP;
 127                         else
 128                                 printk(KERN_WARNING "BOOTP: Ignoring device %s, MTU %d too small", dev->name, dev->mtu);
 129                         if (!(dev->flags & IFF_NOARP))
 130                                 able |= IC_RARP;
 131                         able &= ic_proto_enabled;
 132                         if (ic_proto_enabled && !able)
 133                                 continue;
 134                         oflags = dev->flags;
 135                         if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
 136                                 printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
 137                                 continue;
 138                         }
 139                         if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL)))
 140                                 return -1;
 141                         d->dev = dev;
 142                         *last = d;
 143                         last = &d->next;
 144                         d->flags = oflags;
 145                         d->able = able;
 146                         ic_proto_have_if |= able;
 147                         DBG(("IP-Config: Opened %s (able=%d)\n", dev->name, able));
 148                 }
 149         }
 150         rtnl_shunlock();
 151
 152         *last = NULL;
 153
 154         if (!ic_first_dev) {
 155                 if (user_dev_name[0])
 156                         printk(KERN_ERR "IP-Config: Device `%s' not found.\n", user_dev_name);
 157                 else
 158                         printk(KERN_ERR "IP-Config: No network devices available.\n");
 159                 return -1;
 160         }
 161         return 0;
 162 }
 163
 164 static void __init ic_close_devs(void)
 165 {
 166         struct ic_device *d, *next;
 167         struct net_device *dev;
 168
 169         rtnl_shlock();
 170         next = ic_first_dev;
 171         while ((d = next)) {
 172                 next = d->next;
 173                 dev = d->dev;
 174                 if (dev != ic_dev) {
 175                         DBG(("IP-Config: Downing %s\n", dev->name));
 176                         dev_change_flags(dev, d->flags);
 177                 }
 178                 kfree_s(d, sizeof(struct ic_device));
 179         }
 180         rtnl_shunlock();
 181 }
 182
 183 /*
 184  *      Interface to various network functions.
 185  */
 186
 187 static inline void
 188 set_sockaddr(struct sockaddr_in *sin, u32 addr, u16 port)
 189 {
 190         sin->sin_family = AF_INET;
 191         sin->sin_addr.s_addr = addr;
 192         sin->sin_port = port;
 193 }
 194
 195 static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
 196 {
 197         int res;
 198
 199         mm_segment_t oldfs = get_fs();
 200         set_fs(get_ds());
 201         res = devinet_ioctl(cmd, arg);
 202         set_fs(oldfs);
 203         return res;
 204 }
 205
 206 static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg)
 207 {
 208         int res;
 209
 210         mm_segment_t oldfs = get_fs();
 211         set_fs(get_ds());
 212         res = ip_rt_ioctl(cmd, arg);
 213         set_fs(oldfs);
 214         return res;
 215 }
 216
 217 /*
 218  *      Set up interface addresses and routes.
 219  */
 220
 221 static int __init ic_setup_if(void)
 222 {
 223         struct ifreq ir;
 224         struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
 225         int err;
 226
 227         memset(&ir, 0, sizeof(ir));
 228         strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->name);
 229         set_sockaddr(sin, ic_myaddr, 0);
 230         if ((err = ic_dev_ioctl(SIOCSIFADDR, &ir)) < 0) {
 231                 printk(KERN_ERR "IP-Config: Unable to set interface address (%d).\n", err);
 232                 return -1;
 233         }
 234         set_sockaddr(sin, ic_netmask, 0);
 235         if ((err = ic_dev_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
 236                 printk(KERN_ERR "IP-Config: Unable to set interface netmask (%d).\n", err);
 237                 return -1;
 238         }
 239         set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
 240         if ((err = ic_dev_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
 241                 printk(KERN_ERR "IP-Config: Unable to set interface broadcast address (%d).\n", err);
 242                 return -1;
 243         }
 244         return 0;
 245 }
 246
 247 static int __init ic_setup_routes(void)
 248 {
 249         /* No need to setup device routes, only the default route... */
 250
 251         if (ic_gateway != INADDR_NONE) {
 252                 struct rtentry rm;
 253                 int err;
 254
 255                 memset(&rm, 0, sizeof(rm));
 256                 if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
 257                         printk(KERN_ERR "IP-Config: Gateway not on directly connected network.\n");
 258                         return -1;
 259                 }
 260                 set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
 261                 set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
 262                 set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
 263                 rm.rt_flags = RTF_UP | RTF_GATEWAY;
 264                 if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) {
 265                         printk(KERN_ERR "IP-Config: Cannot add default route (%d).\n", err);
 266                         return -1;
 267                 }
 268         }
 269
 270         return 0;
 271 }
 272
 273 /*
 274  *      Fill in default values for all missing parameters.
 275  */
 276
 277 static int __init ic_defaults(void)
 278 {
 279         /*
 280          *      At this point we have no userspace running so need not
 281          *      claim locks on system_utsname
 282          */
 283
 284         if (!ic_host_name_set)
 285                 strcpy(system_utsname.nodename, in_ntoa(ic_myaddr));
 286
 287         if (root_server_addr == INADDR_NONE)
 288                 root_server_addr = ic_servaddr;
 289
 290         if (ic_netmask == INADDR_NONE) {
 291                 if (IN_CLASSA(ntohl(ic_myaddr)))
 292                         ic_netmask = htonl(IN_CLASSA_NET);
 293                 else if (IN_CLASSB(ntohl(ic_myaddr)))
 294                         ic_netmask = htonl(IN_CLASSB_NET);
 295                 else if (IN_CLASSC(ntohl(ic_myaddr)))
 296                         ic_netmask = htonl(IN_CLASSC_NET);
 297                 else {
 298                         printk(KERN_ERR "IP-Config: Unable to guess netmask for address %u.%u.%u.%u\n",
 299                                 NIPQUAD(ic_myaddr));
 300                         return -1;
 301                 }
 302                 printk("IP-Config: Guessing netmask %u.%u.%u.%u\n", NIPQUAD(ic_netmask));
 303         }
 304
 305         return 0;
 306 }
 307
 308 /*
 309  *      RARP support.
 310  */
 311
 312 #ifdef CONFIG_IP_PNP_RARP
 313
 314 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt);
 315
 316 static struct packet_type rarp_packet_type __initdata = {
 317         __constant_htons(ETH_P_RARP),
 318         NULL,                   /* Listen to all devices */
 319         ic_rarp_recv,
 320         NULL,
 321         NULL
 322 };
 323
 324 static inline void ic_rarp_init(void)
 325 {
 326         dev_add_pack(&rarp_packet_type);
 327 }
 328
 329 static inline void ic_rarp_cleanup(void)
 330 {
 331         dev_remove_pack(&rarp_packet_type);
 332 }
 333
 334 /*
 335  *  Process received RARP packet.
 336  */
 337 static int __init
 338 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt)
 339 {
 340         struct arphdr *rarp = (struct arphdr *)skb->h.raw;
 341         unsigned char *rarp_ptr = (unsigned char *) (rarp + 1);
 342         unsigned long sip, tip;
 343         unsigned char *sha, *tha;               /* s for "source", t for "target" */
 344
 345         /* If we already have a reply, just drop the packet */
 346         if (ic_got_reply)
 347                 goto drop;
 348
 349         /* If this test doesn't pass, it's not IP, or we should ignore it anyway */
 350         if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
 351                 goto drop;
 352
 353         /* If it's not a RARP reply, delete it. */
 354         if (rarp->ar_op != htons(ARPOP_RREPLY))
 355                 goto drop;
 356
 357         /* If it's not Ethernet, delete it. */
 358         if (rarp->ar_pro != htons(ETH_P_IP))
 359                 goto drop;
 360
 361         /* Extract variable-width fields */
 362         sha = rarp_ptr;
 363         rarp_ptr += dev->addr_len;
 364         memcpy(&sip, rarp_ptr, 4);
 365         rarp_ptr += 4;
 366         tha = rarp_ptr;
 367         rarp_ptr += dev->addr_len;
 368         memcpy(&tip, rarp_ptr, 4);
 369
 370         /* Discard packets which are not meant for us. */
 371         if (memcmp(tha, dev->dev_addr, dev->addr_len))
 372                 goto drop;
 373
 374         /* Discard packets which are not from specified server. */
 375         if (ic_servaddr != INADDR_NONE && ic_servaddr != sip)
 376                 goto drop;
 377
 378         /* Victory! The packet is what we were looking for! */
 379         if (!ic_got_reply) {
 380                 ic_got_reply = IC_RARP;
 381                 ic_dev = dev;
 382                 if (ic_myaddr == INADDR_NONE)
 383                         ic_myaddr = tip;
 384                 ic_servaddr = sip;
 385         }
 386
 387         /* And throw the packet out... */
 388 drop:
 389         kfree_skb(skb);
 390         return 0;
 391 }
 392
 393
 394 /*
 395  *  Send RARP request packet over all devices which allow RARP.
 396  */
 397 static void __init ic_rarp_send(void)
 398 {
 399         struct ic_device *d;
 400
 401         for (d=ic_first_dev; d; d=d->next)
 402                 if (d->able & IC_RARP) {
 403                         struct net_device *dev = d->dev;
 404                         arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
 405                                  dev->dev_addr, dev->dev_addr);
 406                 }
 407 }
 408
 409 #endif
 410
 411 /*
 412  *      BOOTP support.
 413  */
 414
 415 #ifdef CONFIG_IP_PNP_BOOTP
 416
 417 struct bootp_pkt {              /* BOOTP packet format */
 418         struct iphdr iph;       /* IP header */
 419         struct udphdr udph;     /* UDP header */
 420         u8 op;                  /* 1=request, 2=reply */
 421         u8 htype;               /* HW address type */
 422         u8 hlen;                /* HW address length */
 423         u8 hops;                /* Used only by gateways */
 424         u32 xid;                /* Transaction ID */
 425         u16 secs;               /* Seconds since we started */
 426         u16 flags;              /* Just what it says */
 427         u32 client_ip;          /* Client's IP address if known */
 428         u32 your_ip;            /* Assigned IP address */
 429         u32 server_ip;          /* Server's IP address */
 430         u32 relay_ip;           /* IP address of BOOTP relay */
 431         u8 hw_addr[16];         /* Client's HW address */
 432         u8 serv_name[64];       /* Server host name */
 433         u8 boot_file[128];      /* Name of boot file */
 434         u8 vendor_area[128];    /* Area for extensions */
 435 };
 436
 437 #define BOOTP_REQUEST 1
 438 #define BOOTP_REPLY 2
 439
 440 static u32 ic_bootp_xid;
 441
 442 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt);
 443
 444 static struct packet_type bootp_packet_type __initdata = {
 445         __constant_htons(ETH_P_IP),
 446         NULL,                   /* Listen to all devices */
 447         ic_bootp_recv,
 448         NULL,
 449         NULL
 450 };
 451
 452
 453 /*
 454  *  Initialize BOOTP extension fields in the request.
 455  */
 456 static void __init ic_bootp_init_ext(u8 *e)
 457 {
 458         *e++ = 99;              /* RFC1048 Magic Cookie */
 459         *e++ = 130;
 460         *e++ = 83;
 461         *e++ = 99;
 462         *e++ = 1;               /* Subnet mask request */
 463         *e++ = 4;
 464         e += 4;
 465         *e++ = 3;               /* Default gateway request */
 466         *e++ = 4;
 467         e += 4;
 468         *e++ = 12;              /* Host name request */
 469         *e++ = 32;
 470         e += 32;
 471         *e++ = 40;              /* NIS Domain name request */
 472         *e++ = 32;
 473         e += 32;
 474         *e++ = 17;              /* Boot path */
 475         *e++ = 32;
 476         e += 32;
 477         *e = 255;               /* End of the list */
 478 }
 479
 480
 481 /*
 482  *  Initialize the BOOTP mechanism.
 483  */
 484 static inline void ic_bootp_init(void)
 485 {
 486         get_random_bytes(&ic_bootp_xid, sizeof(u32));
 487         DBG(("BOOTP: XID=%08x\n", ic_bootp_xid));
 488         dev_add_pack(&bootp_packet_type);
 489 }
 490
 491
 492 /*
 493  *  BOOTP cleanup.
 494  */
 495 static inline void ic_bootp_cleanup(void)
 496 {
 497         dev_remove_pack(&bootp_packet_type);
 498 }
 499
 500
 501 /*
 502  *  Send BOOTP request to single interface.
 503  */
 504 static void __init ic_bootp_send_if(struct ic_device *d, u32 jiffies)
 505 {
 506         struct net_device *dev = d->dev;
 507         struct sk_buff *skb;
 508         struct bootp_pkt *b;
 509         int hh_len = (dev->hard_header_len + 15) & ~15;
 510         struct iphdr *h;
 511
 512         /* Allocate packet */
 513         skb = alloc_skb(sizeof(struct bootp_pkt) + hh_len + 15, GFP_KERNEL);
 514         if (!skb)
 515                 return;
 516         skb_reserve(skb, hh_len);
 517         b = (struct bootp_pkt *) skb_put(skb, sizeof(struct bootp_pkt));
 518         memset(b, 0, sizeof(struct bootp_pkt));
 519
 520         /* Construct IP header */
 521         skb->nh.iph = h = &b->iph;
 522         h->version = 4;
 523         h->ihl = 5;
 524         h->tot_len = htons(sizeof(struct bootp_pkt));
 525         h->frag_off = htons(IP_DF);
 526         h->ttl = 64;
 527         h->protocol = IPPROTO_UDP;
 528         h->daddr = INADDR_BROADCAST;
 529         h->check = ip_fast_csum((unsigned char *) h, h->ihl);
 530
 531         /* Construct UDP header */
 532         b->udph.source = htons(68);
 533         b->udph.dest = htons(67);
 534         b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
 535         /* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
 536
 537         /* Construct BOOTP header */
 538         b->op = BOOTP_REQUEST;
 539         if (dev->type < 256) /* check for false types */
 540                 b->htype = dev->type;
 541         else if (dev->type == ARPHRD_IEEE802_TR) /* fix for token ring */
 542                 b->htype = ARPHRD_IEEE802;
 543         else {
 544                 printk("Unknown ARP type 0x%04x for device %s\n", dev->type, dev->name);
 545                 b->htype = dev->type; /* can cause undefined behavior */
 546         }
 547         b->hlen = dev->addr_len;
 548         memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
 549         b->secs = htons(jiffies / HZ);
 550         b->xid = ic_bootp_xid;
 551         ic_bootp_init_ext(b->vendor_area);
 552
 553         /* Chain packet down the line... */
 554         skb->dev = dev;
 555         skb->protocol = __constant_htons(ETH_P_IP);
 556         if ((dev->hard_header &&
 557              dev->hard_header(skb, dev, ntohs(skb->protocol), dev->broadcast, dev->dev_addr, skb->len) < 0) ||
 558             dev_queue_xmit(skb) < 0)
 559                 printk("E");
 560 }
 561
 562
 563 /*
 564  *  Send BOOTP requests to all interfaces.
 565  */
 566 static void __init ic_bootp_send(u32 jiffies)
 567 {
 568         struct ic_device *d;
 569
 570         for(d=ic_first_dev; d; d=d->next)
 571                 if (d->able & IC_BOOTP)
 572                         ic_bootp_send_if(d, jiffies);
 573 }
 574
 575
 576 /*
 577  *  Copy BOOTP-supplied string if not already set.
 578  */
 579 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
 580 {
 581         if (!len)
 582                 return 0;
 583         if (len > max-1)
 584                 len = max-1;
 585         strncpy(dest, src, len);
 586         dest[len] = '\0';
 587         return 1;
 588 }
 589
 590
 591 /*
 592  *  Process BOOTP extension.
 593  */
 594 static void __init ic_do_bootp_ext(u8 *ext)
 595 {
 596 #ifdef IPCONFIG_DEBUG
 597         u8 *c;
 598
 599         printk("BOOTP: Got extension %02x",*ext);
 600         for(c=ext+2; c<ext+2+ext[1]; c++)
 601                 printk(" %02x", *c);
 602         printk("\n");
 603 #endif
 604
 605         switch (*ext++) {
 606                 case 1:         /* Subnet mask */
 607                         if (ic_netmask == INADDR_NONE)
 608                                 memcpy(&ic_netmask, ext+1, 4);
 609                         break;
 610                 case 3:         /* Default gateway */
 611                         if (ic_gateway == INADDR_NONE)
 612                                 memcpy(&ic_gateway, ext+1, 4);
 613                         break;
 614                 case 12:        /* Host name */
 615                         ic_bootp_string(system_utsname.nodename, ext+1, *ext, __NEW_UTS_LEN);
 616                         ic_host_name_set = 1;
 617                         break;
 618                 case 40:        /* NIS Domain name */
 619                         ic_bootp_string(system_utsname.domainname, ext+1, *ext, __NEW_UTS_LEN);
 620                         break;
 621                 case 17:        /* Root path */
 622                         if (!root_server_path[0])
 623                                 ic_bootp_string(root_server_path, ext+1, *ext, sizeof(root_server_path));
 624                         break;
 625         }
 626 }
 627
 628
 629 /*
 630  *  Receive BOOTP reply.
 631  */
 632 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt)
 633 {
 634         struct bootp_pkt *b = (struct bootp_pkt *) skb->nh.iph;
 635         struct iphdr *h = &b->iph;
 636         int len;
 637
 638         /* If we already have a reply, just drop the packet */
 639         if (ic_got_reply)
 640                 goto drop;
 641
 642         /* Check whether it's a BOOTP packet */
 643         if (skb->pkt_type == PACKET_OTHERHOST ||
 644             skb->len < sizeof(struct udphdr) + sizeof(struct iphdr) ||
 645             h->ihl != 5 ||
 646             h->version != 4 ||
 647             ip_fast_csum((char *) h, h->ihl) != 0 ||
 648             skb->len < ntohs(h->tot_len) ||
 649             h->protocol != IPPROTO_UDP ||
 650             b->udph.source != htons(67) ||
 651             b->udph.dest != htons(68) ||
 652             ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
 653                 goto drop;
 654
 655         /* Fragments are not supported */
 656         if (h->frag_off & htons(IP_OFFSET|IP_MF)) {
 657                 printk(KERN_ERR "BOOTP: Ignoring fragmented reply.\n");
 658                 goto drop;
 659         }
 660
 661         /* Is it a reply to our BOOTP request? */
 662         len = ntohs(b->udph.len) - sizeof(struct udphdr);
 663         if (len < 300 ||                                    /* See RFC 951:2.1 */
 664             b->op != BOOTP_REPLY ||
 665             b->xid != ic_bootp_xid) {
 666                 printk("?");
 667                 goto drop;
 668         }
 669
 670         /* Extract basic fields */
 671         ic_myaddr = b->your_ip;
 672         ic_servaddr = b->server_ip;
 673         ic_got_reply = IC_BOOTP;
 674         ic_dev = dev;
 675
 676         /* Parse extensions */
 677         if (b->vendor_area[0] == 99 &&  /* Check magic cookie */
 678             b->vendor_area[1] == 130 &&
 679             b->vendor_area[2] == 83 &&
 680             b->vendor_area[3] == 99) {
 681                 u8 *ext = &b->vendor_area[4];
 682                 u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
 683                 while (ext < end && *ext != 0xff) {
 684                         if (*ext == 0)          /* Padding */
 685                                 ext++;
 686                         else {
 687                                 u8 *opt = ext;
 688                                 ext += ext[1] + 2;
 689                                 if (ext <= end)
 690                                         ic_do_bootp_ext(opt);
 691                         }
 692                 }
 693         }
 694
 695         if (ic_gateway == INADDR_NONE && b->relay_ip)
 696                 ic_gateway = b->relay_ip;
 697
 698 drop:
 699         kfree_skb(skb);
 700         return 0;
 701 }
 702
 703
 704 #endif
 705
 706
 707 /*
 708  *      Dynamic IP configuration -- BOOTP and RARP.
 709  */
 710
 711 #ifdef CONFIG_IP_PNP_DYNAMIC
 712
 713 static int __init ic_dynamic(void)
 714 {
 715         int retries;
 716         unsigned long timeout, jiff;
 717         unsigned long start_jiffies;
 718         int do_rarp = ic_proto_have_if & IC_RARP;
 719         int do_bootp = ic_proto_have_if & IC_BOOTP;
 720
 721         /*
 722          * If neither BOOTP nor RARP was selected, return with an error. This
 723          * routine gets only called when some pieces of information are mis-
 724          * sing, and without BOOTP and RARP we are not able to get that in-
 725          * formation.
 726          */
 727         if (!ic_proto_enabled) {
 728                 printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
 729                 return -1;
 730         }
 731
 732 #ifdef CONFIG_IP_PNP_BOOTP
 733         if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
 734                 printk(KERN_ERR "BOOTP: No suitable device found.\n");
 735 #endif
 736
 737 #ifdef CONFIG_IP_PNP_RARP
 738         if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
 739                 printk(KERN_ERR "RARP: No suitable device found.\n");
 740 #endif
 741
 742         if (!ic_proto_have_if)
 743                 /* Error message already printed */
 744                 return -1;
 745
 746         /*
 747          * Setup RARP and BOOTP protocols
 748          */
 749 #ifdef CONFIG_IP_PNP_RARP
 750         if (do_rarp)
 751                 ic_rarp_init();
 752 #endif
 753 #ifdef CONFIG_IP_PNP_BOOTP
 754         if (do_bootp)
 755                 ic_bootp_init();
 756 #endif
 757
 758         /*
 759          * Send requests and wait, until we get an answer. This loop
 760          * seems to be a terrible waste of CPU time, but actually there is
 761          * only one process running at all, so we don't need to use any
 762          * scheduler functions.
 763          * [Actually we could now, but the nothing else running note still
 764          *  applies.. - AC]
 765          */
 766         printk(KERN_NOTICE "Sending %s%s%s requests...",
 767                 do_bootp ? "BOOTP" : "",
 768                 do_bootp && do_rarp ? " and " : "",
 769                 do_rarp ? "RARP" : "");
 770         start_jiffies = jiffies;
 771         retries = CONF_RETRIES;
 772         get_random_bytes(&timeout, sizeof(timeout));
 773         timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned) CONF_TIMEOUT_RANDOM);
 774         for(;;) {
 775 #ifdef CONFIG_IP_PNP_BOOTP
 776                 if (do_bootp)
 777                         ic_bootp_send(jiffies - start_jiffies);
 778 #endif
 779 #ifdef CONFIG_IP_PNP_RARP
 780                 if (do_rarp)
 781                         ic_rarp_send();
 782 #endif
 783                 printk(".");
 784                 jiff = jiffies + timeout;
 785                 while (jiffies < jiff && !ic_got_reply)
 786                         ;
 787                 if (ic_got_reply) {
 788                         printk(" OK\n");
 789                         break;
 790                 }
 791                 if (! --retries) {
 792                         printk(" timed out!\n");
 793                         break;
 794                 }
 795                 timeout = timeout CONF_TIMEOUT_MULT;
 796                 if (timeout > CONF_TIMEOUT_MAX)
 797                         timeout = CONF_TIMEOUT_MAX;
 798         }
 799
 800 #ifdef CONFIG_IP_PNP_RARP
 801         if (do_rarp)
 802                 ic_rarp_cleanup();
 803 #endif
 804 #ifdef CONFIG_IP_PNP_BOOTP
 805         if (do_bootp)
 806                 ic_bootp_cleanup();
 807 #endif
 808
 809         if (!ic_got_reply)
 810                 return -1;
 811
 812         printk("IP-Config: Got %s answer from %u.%u.%u.%u, ",
 813                 (ic_got_reply & IC_BOOTP) ? "BOOTP" : "RARP",
 814                 NIPQUAD(ic_servaddr));
 815         printk("my address is %u.%u.%u.%u\n", NIPQUAD(ic_myaddr));
 816
 817         return 0;
 818 }
 819
 820 #endif
 821
 822 /*
 823  *      IP Autoconfig dispatcher.
 824  */
 825
 826 static int __init ip_auto_config(void)
 827 {
 828         if (!ic_enable)
 829                 return 0;
 830
 831         DBG(("IP-Config: Entered.\n"));
 832
 833         /* Setup all network devices */
 834         if (ic_open_devs() < 0)
 835                 return -1;
 836
 837         /*
 838          * If the config information is insufficient (e.g., our IP address or
 839          * IP address of the boot server is missing or we have multiple network
 840          * interfaces and no default was set), use BOOTP or RARP to get the
 841          * missing values.
 842          */
 843         if (ic_myaddr == INADDR_NONE ||
 844 #ifdef CONFIG_ROOT_NFS
 845             (root_server_addr == INADDR_NONE && ic_servaddr == INADDR_NONE) ||
 846 #endif
 847             ic_first_dev->next) {
 848 #ifdef CONFIG_IP_PNP_DYNAMIC
 849                 if (ic_dynamic() < 0) {
 850                         printk(KERN_ERR "IP-Config: Auto-configuration of network failed.\n");
 851                         ic_close_devs();
 852                         return -1;
 853                 }
 854 #else
 855                 printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
 856                 ic_close_devs();
 857                 return -1;
 858 #endif
 859         } else {
 860                 ic_dev = ic_first_dev->dev;     /* Device selected manually or only one device -> use it */
 861         }
 862
 863         /*
 864          * Use defaults whereever applicable.
 865          */
 866         if (ic_defaults() < 0)
 867                 return -1;
 868
 869         /*
 870          * Close all network devices except the device we've
 871          * autoconfigured and set up routes.
 872          */
 873         ic_close_devs();
 874         if (ic_setup_if() < 0 || ic_setup_routes() < 0)
 875                 return -1;
 876
 877         DBG(("IP-Config: device=%s, local=%08x, server=%08x, boot=%08x, gw=%08x, mask=%08x\n",
 878             ic_dev->name, ic_myaddr, ic_servaddr, root_server_addr, ic_gateway, ic_netmask));
 879         DBG(("IP-Config: host=%s, domain=%s, path=`%s'\n", system_utsname.nodename,
 880             system_utsname.domainname, root_server_path));
 881         return 0;
 882 }
 883
 884 module_init(ip_auto_config);
 885
 886
 887 /*
 888  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
 889  *  command line parameter. It consists of option fields separated by colons in
 890  *  the following order:
 891  *
 892  *  <client-ip>:<server-ip>:<gw-ip>:<netmask>:<host name>:<device>:<bootp|rarp>
 893  *
 894  *  Any of the fields can be empty which means to use a default value:
 895  *      <client-ip>     - address given by BOOTP or RARP
 896  *      <server-ip>     - address of host returning BOOTP or RARP packet
 897  *      <gw-ip>         - none, or the address returned by BOOTP
 898  *      <netmask>       - automatically determined from <client-ip>, or the
 899  *                        one returned by BOOTP
 900  *      <host name>     - <client-ip> in ASCII notation, or the name returned
 901  *                        by BOOTP
 902  *      <device>        - use all available devices
 903  *      <bootp|rarp|both|off> - use both protocols to determine my own address
 904  */
 905 static int __init ic_proto_name(char *name)
 906 {
 907         if (!strcmp(name, "off")) {
 908                 ic_proto_enabled = 0;
 909                 return 1;
 910         }
 911 #ifdef CONFIG_IP_PNP_BOOTP
 912         else if (!strcmp(name, "bootp")) {
 913                 ic_proto_enabled &= ~IC_RARP;
 914                 return 1;
 915         }
 916 #endif
 917 #ifdef CONFIG_IP_PNP_RARP
 918         else if (!strcmp(name, "rarp")) {
 919                 ic_proto_enabled &= ~IC_BOOTP;
 920                 return 1;
 921         }
 922 #endif
 923 #ifdef CONFIG_IP_PNP_DYNAMIC
 924         else if (!strcmp(name, "both")) {
 925                 return 1;
 926         }
 927 #endif
 928         return 0;
 929 }
 930
 931 static int __init ip_auto_config_setup(char *addrs)
 932 {
 933         char *cp, *ip, *dp;
 934         int num = 0;
 935
 936         ic_set_manually = 1;
 937         if (!strcmp(addrs, "off")) {
 938                 ic_enable = 0;
 939                 return 1;
 940         }
 941         if (ic_proto_name(addrs))
 942                 return 1;
 943
 944         /* Parse the whole string */
 945         ip = addrs;
 946         while (ip && *ip) {
 947                 if ((cp = strchr(ip, ':')))
 948                         *cp++ = '\0';
 949                 if (strlen(ip) > 0) {
 950                         DBG(("IP-Config: Parameter #%d: `%s'\n", num, ip));
 951                         switch (num) {
 952                         case 0:
 953                                 if ((ic_myaddr = in_aton(ip)) == INADDR_ANY)
 954                                         ic_myaddr = INADDR_NONE;
 955                                 break;
 956                         case 1:
 957                                 if ((ic_servaddr = in_aton(ip)) == INADDR_ANY)
 958                                         ic_servaddr = INADDR_NONE;
 959                                 break;
 960                         case 2:
 961                                 if ((ic_gateway = in_aton(ip)) == INADDR_ANY)
 962                                         ic_gateway = INADDR_NONE;
 963                                 break;
 964                         case 3:
 965                                 if ((ic_netmask = in_aton(ip)) == INADDR_ANY)
 966                                         ic_netmask = INADDR_NONE;
 967                                 break;
 968                         case 4:
 969                                 if ((dp = strchr(ip, '.'))) {
 970                                         *dp++ = '\0';
 971                                         strncpy(system_utsname.domainname, dp, __NEW_UTS_LEN);
 972                                         system_utsname.domainname[__NEW_UTS_LEN] = '\0';
 973                                 }
 974                                 strncpy(system_utsname.nodename, ip, __NEW_UTS_LEN);
 975                                 system_utsname.nodename[__NEW_UTS_LEN] = '\0';
 976                                 ic_host_name_set = 1;
 977                                 break;
 978                         case 5:
 979                                 strncpy(user_dev_name, ip, IFNAMSIZ);
 980                                 user_dev_name[IFNAMSIZ-1] = '\0';
 981                                 break;
 982                         case 6:
 983                                 ic_proto_name(ip);
 984                                 break;
 985                         }
 986                 }
 987                 ip = cp;
 988                 num++;
 989         }
 990
 991         return 1;
 992 }
 993
 994 static int __init nfsaddrs_config_setup(char *addrs)
 995 {
 996         return ip_auto_config_setup(addrs);
 997 }
 998
 999 __setup("ip=", ip_auto_config_setup);
1000 __setup("nfsaddrs=", nfsaddrs_config_setup);