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