net/ipv4/ipconfig.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or
   4  *  user-supplied information to configure own IP address and routes.
   5  *
   6  *  Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
   7  *
   8  *  Derived from network configuration code in fs/nfs/nfsroot.c,
   9  *  originally Copyright (C) 1995, 1996 Gero Kuhlmann and me.
  10  *
  11  *  BOOTP rewritten to construct and analyse packets itself instead
  12  *  of misusing the IP layer. num_bugs_causing_wrong_arp_replies--;
  13  *                                           -- MJ, December 1998
  14  *
  15  *  Fixed ip_auto_config_setup calling at startup in the new "Linker Magic"
  16  *  initialization scheme.
  17  *      - Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999
  18  *
  19  *  DHCP support added.  To users this looks like a whole separate
  20  *  protocol, but we know it's just a bag on the side of BOOTP.
  21  *              -- Chip Salzenberg <chip@valinux.com>, May 2000
  22  *
  23  *  Ported DHCP support from 2.2.16 to 2.4.0-test4
  24  *              -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000
  25  *
  26  *  Merged changes from 2.2.19 into 2.4.3
  27  *              -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001
  28  *
  29  *  Multiple Nameservers in /proc/net/pnp
  30  *              --  Josef Siemes <jsiemes@web.de>, Aug 2002
  31  *
  32  *  NTP servers in /proc/net/ipconfig/ntp_servers
  33  *              --  Chris Novakovic <chris@chrisn.me.uk>, April 2018
  34  */
  35
  36 #include <linux/types.h>
  37 #include <linux/string.h>
  38 #include <linux/kernel.h>
  39 #include <linux/jiffies.h>
  40 #include <linux/random.h>
  41 #include <linux/init.h>
  42 #include <linux/utsname.h>
  43 #include <linux/in.h>
  44 #include <linux/if.h>
  45 #include <linux/inet.h>
  46 #include <linux/inetdevice.h>
  47 #include <linux/netdevice.h>
  48 #include <linux/if_arp.h>
  49 #include <linux/skbuff.h>
  50 #include <linux/ip.h>
  51 #include <linux/socket.h>
  52 #include <linux/route.h>
  53 #include <linux/udp.h>
  54 #include <linux/proc_fs.h>
  55 #include <linux/seq_file.h>
  56 #include <linux/major.h>
  57 #include <linux/root_dev.h>
  58 #include <linux/delay.h>
  59 #include <linux/nfs_fs.h>
  60 #include <linux/slab.h>
  61 #include <linux/export.h>
  62 #include <net/net_namespace.h>
  63 #include <net/arp.h>
  64 #include <net/ip.h>
  65 #include <net/ipconfig.h>
  66 #include <net/route.h>
  67
  68 #include <linux/uaccess.h>
  69 #include <net/checksum.h>
  70 #include <asm/processor.h>
  71
  72 #if defined(CONFIG_IP_PNP_DHCP)
  73 #define IPCONFIG_DHCP
  74 #endif
  75 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
  76 #define IPCONFIG_BOOTP
  77 #endif
  78 #if defined(CONFIG_IP_PNP_RARP)
  79 #define IPCONFIG_RARP
  80 #endif
  81 #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
  82 #define IPCONFIG_DYNAMIC
  83 #endif
  84
  85 /* Define the friendly delay before and after opening net devices */
  86 #define CONF_POST_OPEN          10      /* After opening: 10 msecs */
  87
  88 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
  89 #define CONF_OPEN_RETRIES       2       /* (Re)open devices twice */
  90 #define CONF_SEND_RETRIES       6       /* Send six requests per open */
  91 #define CONF_BASE_TIMEOUT       (HZ*2)  /* Initial timeout: 2 seconds */
  92 #define CONF_TIMEOUT_RANDOM     (HZ)    /* Maximum amount of randomization */
  93 #define CONF_TIMEOUT_MULT       *7/4    /* Rate of timeout growth */
  94 #define CONF_TIMEOUT_MAX        (HZ*30) /* Maximum allowed timeout */
  95 #define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
  96                                            - '3' from resolv.h */
  97 #define CONF_NTP_SERVERS_MAX   3        /* Maximum number of NTP servers */
  98
  99 #define NONE cpu_to_be32(INADDR_NONE)
 100 #define ANY cpu_to_be32(INADDR_ANY)
 101
 102 /* Wait for carrier timeout default in seconds */
 103 static unsigned int carrier_timeout = 120;
 104
 105 /*
 106  * Public IP configuration
 107  */
 108
 109 /* This is used by platforms which might be able to set the ipconfig
 110  * variables using firmware environment vars.  If this is set, it will
 111  * ignore such firmware variables.
 112  */
 113 int ic_set_manually __initdata = 0;             /* IPconfig parameters set manually */
 114
 115 static int ic_enable __initdata;                /* IP config enabled? */
 116
 117 /* Protocol choice */
 118 int ic_proto_enabled __initdata = 0
 119 #ifdef IPCONFIG_BOOTP
 120                         | IC_BOOTP
 121 #endif
 122 #ifdef CONFIG_IP_PNP_DHCP
 123                         | IC_USE_DHCP
 124 #endif
 125 #ifdef IPCONFIG_RARP
 126                         | IC_RARP
 127 #endif
 128                         ;
 129
 130 static int ic_host_name_set __initdata; /* Host name set by us? */
 131
 132 __be32 ic_myaddr = NONE;                /* My IP address */
 133 static __be32 ic_netmask = NONE;        /* Netmask for local subnet */
 134 __be32 ic_gateway = NONE;       /* Gateway IP address */
 135
 136 #ifdef IPCONFIG_DYNAMIC
 137 static __be32 ic_addrservaddr = NONE;   /* IP Address of the IP addresses'server */
 138 #endif
 139
 140 __be32 ic_servaddr = NONE;      /* Boot server IP address */
 141
 142 __be32 root_server_addr = NONE; /* Address of NFS server */
 143 u8 root_server_path[256] = { 0, };      /* Path to mount as root */
 144
 145 /* vendor class identifier */
 146 static char vendor_class_identifier[253] __initdata;
 147
 148 #if defined(CONFIG_IP_PNP_DHCP)
 149 static char dhcp_client_identifier[253] __initdata;
 150 #endif
 151
 152 /* Persistent data: */
 153
 154 #ifdef IPCONFIG_DYNAMIC
 155 static int ic_proto_used;                       /* Protocol used, if any */
 156 #else
 157 #define ic_proto_used 0
 158 #endif
 159 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
 160 static __be32 ic_ntp_servers[CONF_NTP_SERVERS_MAX]; /* NTP server IP addresses */
 161 static u8 ic_domain[64];                /* DNS (not NIS) domain name */
 162
 163 /*
 164  * Private state.
 165  */
 166
 167 /* Name of user-selected boot device */
 168 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
 169
 170 /* Protocols supported by available interfaces */
 171 static int ic_proto_have_if __initdata;
 172
 173 /* MTU for boot device */
 174 static int ic_dev_mtu __initdata;
 175
 176 #ifdef IPCONFIG_DYNAMIC
 177 static DEFINE_SPINLOCK(ic_recv_lock);
 178 static volatile int ic_got_reply __initdata;    /* Proto(s) that replied */
 179 #endif
 180 #ifdef IPCONFIG_DHCP
 181 static int ic_dhcp_msgtype __initdata;  /* DHCP msg type received */
 182 #endif
 183
 184
 185 /*
 186  *      Network devices
 187  */
 188
 189 struct ic_device {
 190         struct ic_device *next;
 191         struct net_device *dev;
 192         unsigned short flags;
 193         short able;
 194         __be32 xid;
 195 };
 196
 197 static struct ic_device *ic_first_dev __initdata;       /* List of open device */
 198 static struct ic_device *ic_dev __initdata;             /* Selected device */
 199
 200 static bool __init ic_is_init_dev(struct net_device *dev)
 201 {
 202         if (dev->flags & IFF_LOOPBACK)
 203                 return false;
 204         return user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
 205             (!(dev->flags & IFF_LOOPBACK) &&
 206              (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
 207              strncmp(dev->name, "dummy", 5));
 208 }
 209
 210 static int __init ic_open_devs(void)
 211 {
 212         struct ic_device *d, **last;
 213         struct net_device *dev;
 214         unsigned short oflags;
 215         unsigned long start, next_msg;
 216
 217         last = &ic_first_dev;
 218         rtnl_lock();
 219
 220         /* bring loopback device up first */
 221         for_each_netdev(&init_net, dev) {
 222                 if (!(dev->flags & IFF_LOOPBACK))
 223                         continue;
 224                 if (dev_change_flags(dev, dev->flags | IFF_UP, NULL) < 0)
 225                         pr_err("IP-Config: Failed to open %s\n", dev->name);
 226         }
 227
 228         for_each_netdev(&init_net, dev) {
 229                 if (ic_is_init_dev(dev)) {
 230                         int able = 0;
 231                         if (dev->mtu >= 364)
 232                                 able |= IC_BOOTP;
 233                         else
 234                                 pr_warn("DHCP/BOOTP: Ignoring device %s, MTU %d too small\n",
 235                                         dev->name, dev->mtu);
 236                         if (!(dev->flags & IFF_NOARP))
 237                                 able |= IC_RARP;
 238                         able &= ic_proto_enabled;
 239                         if (ic_proto_enabled && !able)
 240                                 continue;
 241                         oflags = dev->flags;
 242                         if (dev_change_flags(dev, oflags | IFF_UP, NULL) < 0) {
 243                                 pr_err("IP-Config: Failed to open %s\n",
 244                                        dev->name);
 245                                 continue;
 246                         }
 247                         if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
 248                                 rtnl_unlock();
 249                                 return -ENOMEM;
 250                         }
 251                         d->dev = dev;
 252                         *last = d;
 253                         last = &d->next;
 254                         d->flags = oflags;
 255                         d->able = able;
 256                         if (able & IC_BOOTP)
 257                                 get_random_bytes(&d->xid, sizeof(__be32));
 258                         else
 259                                 d->xid = 0;
 260                         ic_proto_have_if |= able;
 261                         pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n",
 262                                  dev->name, able, d->xid);
 263                 }
 264         }
 265
 266         /* no point in waiting if we could not bring up at least one device */
 267         if (!ic_first_dev)
 268                 goto have_carrier;
 269
 270         /* wait for a carrier on at least one device */
 271         start = jiffies;
 272         next_msg = start + msecs_to_jiffies(20000);
 273         while (time_before(jiffies, start +
 274                            msecs_to_jiffies(carrier_timeout * 1000))) {
 275                 int wait, elapsed;
 276
 277                 for_each_netdev(&init_net, dev)
 278                         if (ic_is_init_dev(dev) && netif_carrier_ok(dev))
 279                                 goto have_carrier;
 280
 281                 msleep(1);
 282
 283                 if (time_before(jiffies, next_msg))
 284                         continue;
 285
 286                 elapsed = jiffies_to_msecs(jiffies - start);
 287                 wait = (carrier_timeout * 1000 - elapsed + 500) / 1000;
 288                 pr_info("Waiting up to %d more seconds for network.\n", wait);
 289                 next_msg = jiffies + msecs_to_jiffies(20000);
 290         }
 291 have_carrier:
 292         rtnl_unlock();
 293
 294         *last = NULL;
 295
 296         if (!ic_first_dev) {
 297                 if (user_dev_name[0])
 298                         pr_err("IP-Config: Device `%s' not found\n",
 299                                user_dev_name);
 300                 else
 301                         pr_err("IP-Config: No network devices available\n");
 302                 return -ENODEV;
 303         }
 304         return 0;
 305 }
 306
 307 /* Close all network interfaces except the one we've autoconfigured, and its
 308  * lowers, in case it's a stacked virtual interface.
 309  */
 310 static void __init ic_close_devs(void)
 311 {
 312         struct net_device *selected_dev = ic_dev ? ic_dev->dev : NULL;
 313         struct ic_device *d, *next;
 314         struct net_device *dev;
 315
 316         rtnl_lock();
 317         next = ic_first_dev;
 318         while ((d = next)) {
 319                 bool bring_down = (d != ic_dev);
 320                 struct net_device *lower;
 321                 struct list_head *iter;
 322
 323                 next = d->next;
 324                 dev = d->dev;
 325
 326                 if (selected_dev) {
 327                         netdev_for_each_lower_dev(selected_dev, lower, iter) {
 328                                 if (dev == lower) {
 329                                         bring_down = false;
 330                                         break;
 331                                 }
 332                         }
 333                 }
 334                 if (bring_down) {
 335                         pr_debug("IP-Config: Downing %s\n", dev->name);
 336                         dev_change_flags(dev, d->flags, NULL);
 337                 }
 338                 kfree(d);
 339         }
 340         rtnl_unlock();
 341 }
 342
 343 /*
 344  *      Interface to various network functions.
 345  */
 346
 347 static inline void
 348 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
 349 {
 350         sin->sin_family = AF_INET;
 351         sin->sin_addr.s_addr = addr;
 352         sin->sin_port = port;
 353 }
 354
 355 /*
 356  *      Set up interface addresses and routes.
 357  */
 358
 359 static int __init ic_setup_if(void)
 360 {
 361         struct ifreq ir;
 362         struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
 363         int err;
 364
 365         memset(&ir, 0, sizeof(ir));
 366         strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name);
 367         set_sockaddr(sin, ic_myaddr, 0);
 368         if ((err = devinet_ioctl(&init_net, SIOCSIFADDR, &ir)) < 0) {
 369                 pr_err("IP-Config: Unable to set interface address (%d)\n",
 370                        err);
 371                 return -1;
 372         }
 373         set_sockaddr(sin, ic_netmask, 0);
 374         if ((err = devinet_ioctl(&init_net, SIOCSIFNETMASK, &ir)) < 0) {
 375                 pr_err("IP-Config: Unable to set interface netmask (%d)\n",
 376                        err);
 377                 return -1;
 378         }
 379         set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
 380         if ((err = devinet_ioctl(&init_net, SIOCSIFBRDADDR, &ir)) < 0) {
 381                 pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
 382                        err);
 383                 return -1;
 384         }
 385         /* Handle the case where we need non-standard MTU on the boot link (a network
 386          * using jumbo frames, for instance).  If we can't set the mtu, don't error
 387          * out, we'll try to muddle along.
 388          */
 389         if (ic_dev_mtu != 0) {
 390                 rtnl_lock();
 391                 if ((err = dev_set_mtu(ic_dev->dev, ic_dev_mtu)) < 0)
 392                         pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
 393                                ic_dev_mtu, err);
 394                 rtnl_unlock();
 395         }
 396         return 0;
 397 }
 398
 399 static int __init ic_setup_routes(void)
 400 {
 401         /* No need to setup device routes, only the default route... */
 402
 403         if (ic_gateway != NONE) {
 404                 struct rtentry rm;
 405                 int err;
 406
 407                 memset(&rm, 0, sizeof(rm));
 408                 if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
 409                         pr_err("IP-Config: Gateway not on directly connected network\n");
 410                         return -1;
 411                 }
 412                 set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
 413                 set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
 414                 set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
 415                 rm.rt_flags = RTF_UP | RTF_GATEWAY;
 416                 if ((err = ip_rt_ioctl(&init_net, SIOCADDRT, &rm)) < 0) {
 417                         pr_err("IP-Config: Cannot add default route (%d)\n",
 418                                err);
 419                         return -1;
 420                 }
 421         }
 422
 423         return 0;
 424 }
 425
 426 /*
 427  *      Fill in default values for all missing parameters.
 428  */
 429
 430 static int __init ic_defaults(void)
 431 {
 432         /*
 433          *      At this point we have no userspace running so need not
 434          *      claim locks on system_utsname
 435          */
 436
 437         if (!ic_host_name_set)
 438                 sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
 439
 440         if (root_server_addr == NONE)
 441                 root_server_addr = ic_servaddr;
 442
 443         if (ic_netmask == NONE) {
 444                 if (IN_CLASSA(ntohl(ic_myaddr)))
 445                         ic_netmask = htonl(IN_CLASSA_NET);
 446                 else if (IN_CLASSB(ntohl(ic_myaddr)))
 447                         ic_netmask = htonl(IN_CLASSB_NET);
 448                 else if (IN_CLASSC(ntohl(ic_myaddr)))
 449                         ic_netmask = htonl(IN_CLASSC_NET);
 450                 else if (IN_CLASSE(ntohl(ic_myaddr)))
 451                         ic_netmask = htonl(IN_CLASSE_NET);
 452                 else {
 453                         pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
 454                                &ic_myaddr);
 455                         return -1;
 456                 }
 457                 pr_notice("IP-Config: Guessing netmask %pI4\n",
 458                           &ic_netmask);
 459         }
 460
 461         return 0;
 462 }
 463
 464 /*
 465  *      RARP support.
 466  */
 467
 468 #ifdef IPCONFIG_RARP
 469
 470 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
 471
 472 static struct packet_type rarp_packet_type __initdata = {
 473         .type = cpu_to_be16(ETH_P_RARP),
 474         .func = ic_rarp_recv,
 475 };
 476
 477 static inline void __init ic_rarp_init(void)
 478 {
 479         dev_add_pack(&rarp_packet_type);
 480 }
 481
 482 static inline void __init ic_rarp_cleanup(void)
 483 {
 484         dev_remove_pack(&rarp_packet_type);
 485 }
 486
 487 /*
 488  *  Process received RARP packet.
 489  */
 490 static int __init
 491 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 492 {
 493         struct arphdr *rarp;
 494         unsigned char *rarp_ptr;
 495         __be32 sip, tip;
 496         unsigned char *tha;             /* t for "target" */
 497         struct ic_device *d;
 498
 499         if (!net_eq(dev_net(dev), &init_net))
 500                 goto drop;
 501
 502         skb = skb_share_check(skb, GFP_ATOMIC);
 503         if (!skb)
 504                 return NET_RX_DROP;
 505
 506         if (!pskb_may_pull(skb, sizeof(struct arphdr)))
 507                 goto drop;
 508
 509         /* Basic sanity checks can be done without the lock.  */
 510         rarp = (struct arphdr *)skb_transport_header(skb);
 511
 512         /* If this test doesn't pass, it's not IP, or we should
 513          * ignore it anyway.
 514          */
 515         if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
 516                 goto drop;
 517
 518         /* If it's not a RARP reply, delete it. */
 519         if (rarp->ar_op != htons(ARPOP_RREPLY))
 520                 goto drop;
 521
 522         /* If it's not Ethernet, delete it. */
 523         if (rarp->ar_pro != htons(ETH_P_IP))
 524                 goto drop;
 525
 526         if (!pskb_may_pull(skb, arp_hdr_len(dev)))
 527                 goto drop;
 528
 529         /* OK, it is all there and looks valid, process... */
 530         rarp = (struct arphdr *)skb_transport_header(skb);
 531         rarp_ptr = (unsigned char *) (rarp + 1);
 532
 533         /* One reply at a time, please. */
 534         spin_lock(&ic_recv_lock);
 535
 536         /* If we already have a reply, just drop the packet */
 537         if (ic_got_reply)
 538                 goto drop_unlock;
 539
 540         /* Find the ic_device that the packet arrived on */
 541         d = ic_first_dev;
 542         while (d && d->dev != dev)
 543                 d = d->next;
 544         if (!d)
 545                 goto drop_unlock;       /* should never happen */
 546
 547         /* Extract variable-width fields */
 548         rarp_ptr += dev->addr_len;
 549         memcpy(&sip, rarp_ptr, 4);
 550         rarp_ptr += 4;
 551         tha = rarp_ptr;
 552         rarp_ptr += dev->addr_len;
 553         memcpy(&tip, rarp_ptr, 4);
 554
 555         /* Discard packets which are not meant for us. */
 556         if (memcmp(tha, dev->dev_addr, dev->addr_len))
 557                 goto drop_unlock;
 558
 559         /* Discard packets which are not from specified server. */
 560         if (ic_servaddr != NONE && ic_servaddr != sip)
 561                 goto drop_unlock;
 562
 563         /* We have a winner! */
 564         ic_dev = d;
 565         if (ic_myaddr == NONE)
 566                 ic_myaddr = tip;
 567         ic_servaddr = sip;
 568         ic_addrservaddr = sip;
 569         ic_got_reply = IC_RARP;
 570
 571 drop_unlock:
 572         /* Show's over.  Nothing to see here.  */
 573         spin_unlock(&ic_recv_lock);
 574
 575 drop:
 576         /* Throw the packet out. */
 577         kfree_skb(skb);
 578         return 0;
 579 }
 580
 581
 582 /*
 583  *  Send RARP request packet over a single interface.
 584  */
 585 static void __init ic_rarp_send_if(struct ic_device *d)
 586 {
 587         struct net_device *dev = d->dev;
 588         arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
 589                  dev->dev_addr, dev->dev_addr);
 590 }
 591 #endif
 592
 593 /*
 594  *  Predefine Nameservers
 595  */
 596 static inline void __init ic_nameservers_predef(void)
 597 {
 598         int i;
 599
 600         for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
 601                 ic_nameservers[i] = NONE;
 602 }
 603
 604 /* Predefine NTP servers */
 605 static inline void __init ic_ntp_servers_predef(void)
 606 {
 607         int i;
 608
 609         for (i = 0; i < CONF_NTP_SERVERS_MAX; i++)
 610                 ic_ntp_servers[i] = NONE;
 611 }
 612
 613 /*
 614  *      DHCP/BOOTP support.
 615  */
 616
 617 #ifdef IPCONFIG_BOOTP
 618
 619 struct bootp_pkt {              /* BOOTP packet format */
 620         struct iphdr iph;       /* IP header */
 621         struct udphdr udph;     /* UDP header */
 622         u8 op;                  /* 1=request, 2=reply */
 623         u8 htype;               /* HW address type */
 624         u8 hlen;                /* HW address length */
 625         u8 hops;                /* Used only by gateways */
 626         __be32 xid;             /* Transaction ID */
 627         __be16 secs;            /* Seconds since we started */
 628         __be16 flags;           /* Just what it says */
 629         __be32 client_ip;               /* Client's IP address if known */
 630         __be32 your_ip;         /* Assigned IP address */
 631         __be32 server_ip;               /* (Next, e.g. NFS) Server's IP address */
 632         __be32 relay_ip;                /* IP address of BOOTP relay */
 633         u8 hw_addr[16];         /* Client's HW address */
 634         u8 serv_name[64];       /* Server host name */
 635         u8 boot_file[128];      /* Name of boot file */
 636         u8 exten[312];          /* DHCP options / BOOTP vendor extensions */
 637 };
 638
 639 /* packet ops */
 640 #define BOOTP_REQUEST   1
 641 #define BOOTP_REPLY     2
 642
 643 /* DHCP message types */
 644 #define DHCPDISCOVER    1
 645 #define DHCPOFFER       2
 646 #define DHCPREQUEST     3
 647 #define DHCPDECLINE     4
 648 #define DHCPACK         5
 649 #define DHCPNAK         6
 650 #define DHCPRELEASE     7
 651 #define DHCPINFORM      8
 652
 653 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
 654
 655 static struct packet_type bootp_packet_type __initdata = {
 656         .type = cpu_to_be16(ETH_P_IP),
 657         .func = ic_bootp_recv,
 658 };
 659
 660 /*
 661  *  Initialize DHCP/BOOTP extension fields in the request.
 662  */
 663
 664 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
 665
 666 #ifdef IPCONFIG_DHCP
 667
 668 static void __init
 669 ic_dhcp_init_options(u8 *options, struct ic_device *d)
 670 {
 671         u8 mt = ((ic_servaddr == NONE)
 672                  ? DHCPDISCOVER : DHCPREQUEST);
 673         u8 *e = options;
 674         int len;
 675
 676         pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
 677
 678         memcpy(e, ic_bootp_cookie, 4);  /* RFC1048 Magic Cookie */
 679         e += 4;
 680
 681         *e++ = 53;              /* DHCP message type */
 682         *e++ = 1;
 683         *e++ = mt;
 684
 685         if (mt == DHCPREQUEST) {
 686                 *e++ = 54;      /* Server ID (IP address) */
 687                 *e++ = 4;
 688                 memcpy(e, &ic_servaddr, 4);
 689                 e += 4;
 690
 691                 *e++ = 50;      /* Requested IP address */
 692                 *e++ = 4;
 693                 memcpy(e, &ic_myaddr, 4);
 694                 e += 4;
 695         }
 696
 697         /* always? */
 698         {
 699                 static const u8 ic_req_params[] = {
 700                         1,      /* Subnet mask */
 701                         3,      /* Default gateway */
 702                         6,      /* DNS server */
 703                         12,     /* Host name */
 704                         15,     /* Domain name */
 705                         17,     /* Boot path */
 706                         26,     /* MTU */
 707                         40,     /* NIS domain name */
 708                         42,     /* NTP servers */
 709                 };
 710
 711                 *e++ = 55;      /* Parameter request list */
 712                 *e++ = sizeof(ic_req_params);
 713                 memcpy(e, ic_req_params, sizeof(ic_req_params));
 714                 e += sizeof(ic_req_params);
 715
 716                 if (ic_host_name_set) {
 717                         *e++ = 12;      /* host-name */
 718                         len = strlen(utsname()->nodename);
 719                         *e++ = len;
 720                         memcpy(e, utsname()->nodename, len);
 721                         e += len;
 722                 }
 723                 if (*vendor_class_identifier) {
 724                         pr_info("DHCP: sending class identifier \"%s\"\n",
 725                                 vendor_class_identifier);
 726                         *e++ = 60;      /* Class-identifier */
 727                         len = strlen(vendor_class_identifier);
 728                         *e++ = len;
 729                         memcpy(e, vendor_class_identifier, len);
 730                         e += len;
 731                 }
 732                 len = strlen(dhcp_client_identifier + 1);
 733                 /* the minimum length of identifier is 2, include 1 byte type,
 734                  * and can not be larger than the length of options
 735                  */
 736                 if (len >= 1 && len < 312 - (e - options) - 1) {
 737                         *e++ = 61;
 738                         *e++ = len + 1;
 739                         memcpy(e, dhcp_client_identifier, len + 1);
 740                         e += len + 1;
 741                 }
 742         }
 743
 744         *e++ = 255;     /* End of the list */
 745 }
 746
 747 #endif /* IPCONFIG_DHCP */
 748
 749 static void __init ic_bootp_init_ext(u8 *e)
 750 {
 751         memcpy(e, ic_bootp_cookie, 4);  /* RFC1048 Magic Cookie */
 752         e += 4;
 753         *e++ = 1;               /* Subnet mask request */
 754         *e++ = 4;
 755         e += 4;
 756         *e++ = 3;               /* Default gateway request */
 757         *e++ = 4;
 758         e += 4;
 759 #if CONF_NAMESERVERS_MAX > 0
 760         *e++ = 6;               /* (DNS) name server request */
 761         *e++ = 4 * CONF_NAMESERVERS_MAX;
 762         e += 4 * CONF_NAMESERVERS_MAX;
 763 #endif
 764         *e++ = 12;              /* Host name request */
 765         *e++ = 32;
 766         e += 32;
 767         *e++ = 40;              /* NIS Domain name request */
 768         *e++ = 32;
 769         e += 32;
 770         *e++ = 17;              /* Boot path */
 771         *e++ = 40;
 772         e += 40;
 773
 774         *e++ = 57;              /* set extension buffer size for reply */
 775         *e++ = 2;
 776         *e++ = 1;               /* 128+236+8+20+14, see dhcpd sources */
 777         *e++ = 150;
 778
 779         *e++ = 255;             /* End of the list */
 780 }
 781
 782
 783 /*
 784  *  Initialize the DHCP/BOOTP mechanism.
 785  */
 786 static inline void __init ic_bootp_init(void)
 787 {
 788         /* Re-initialise all name servers and NTP servers to NONE, in case any
 789          * were set via the "ip=" or "nfsaddrs=" kernel command line parameters:
 790          * any IP addresses specified there will already have been decoded but
 791          * are no longer needed
 792          */
 793         ic_nameservers_predef();
 794         ic_ntp_servers_predef();
 795
 796         dev_add_pack(&bootp_packet_type);
 797 }
 798
 799
 800 /*
 801  *  DHCP/BOOTP cleanup.
 802  */
 803 static inline void __init ic_bootp_cleanup(void)
 804 {
 805         dev_remove_pack(&bootp_packet_type);
 806 }
 807
 808
 809 /*
 810  *  Send DHCP/BOOTP request to single interface.
 811  */
 812 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
 813 {
 814         struct net_device *dev = d->dev;
 815         struct sk_buff *skb;
 816         struct bootp_pkt *b;
 817         struct iphdr *h;
 818         int hlen = LL_RESERVED_SPACE(dev);
 819         int tlen = dev->needed_tailroom;
 820
 821         /* Allocate packet */
 822         skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
 823                         GFP_KERNEL);
 824         if (!skb)
 825                 return;
 826         skb_reserve(skb, hlen);
 827         b = skb_put_zero(skb, sizeof(struct bootp_pkt));
 828
 829         /* Construct IP header */
 830         skb_reset_network_header(skb);
 831         h = ip_hdr(skb);
 832         h->version = 4;
 833         h->ihl = 5;
 834         h->tot_len = htons(sizeof(struct bootp_pkt));
 835         h->frag_off = htons(IP_DF);
 836         h->ttl = 64;
 837         h->protocol = IPPROTO_UDP;
 838         h->daddr = htonl(INADDR_BROADCAST);
 839         h->check = ip_fast_csum((unsigned char *) h, h->ihl);
 840
 841         /* Construct UDP header */
 842         b->udph.source = htons(68);
 843         b->udph.dest = htons(67);
 844         b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
 845         /* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
 846
 847         /* Construct DHCP/BOOTP header */
 848         b->op = BOOTP_REQUEST;
 849         if (dev->type < 256) /* check for false types */
 850                 b->htype = dev->type;
 851         else if (dev->type == ARPHRD_FDDI)
 852                 b->htype = ARPHRD_ETHER;
 853         else {
 854                 pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
 855                         dev->name);
 856                 b->htype = dev->type; /* can cause undefined behavior */
 857         }
 858
 859         /* server_ip and your_ip address are both already zero per RFC2131 */
 860         b->hlen = dev->addr_len;
 861         memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
 862         b->secs = htons(jiffies_diff / HZ);
 863         b->xid = d->xid;
 864
 865         /* add DHCP options or BOOTP extensions */
 866 #ifdef IPCONFIG_DHCP
 867         if (ic_proto_enabled & IC_USE_DHCP)
 868                 ic_dhcp_init_options(b->exten, d);
 869         else
 870 #endif
 871                 ic_bootp_init_ext(b->exten);
 872
 873         /* Chain packet down the line... */
 874         skb->dev = dev;
 875         skb->protocol = htons(ETH_P_IP);
 876         if (dev_hard_header(skb, dev, ntohs(skb->protocol),
 877                             dev->broadcast, dev->dev_addr, skb->len) < 0) {
 878                 kfree_skb(skb);
 879                 printk("E");
 880                 return;
 881         }
 882
 883         if (dev_queue_xmit(skb) < 0)
 884                 printk("E");
 885 }
 886
 887
 888 /*
 889  *  Copy BOOTP-supplied string
 890  */
 891 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
 892 {
 893         if (!len)
 894                 return 0;
 895         if (len > max-1)
 896                 len = max-1;
 897         memcpy(dest, src, len);
 898         dest[len] = '\0';
 899         return 1;
 900 }
 901
 902
 903 /*
 904  *  Process BOOTP extensions.
 905  */
 906 static void __init ic_do_bootp_ext(u8 *ext)
 907 {
 908         u8 servers;
 909         int i;
 910         __be16 mtu;
 911
 912         u8 *c;
 913
 914         pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
 915         for (c=ext+2; c<ext+2+ext[1]; c++)
 916                 pr_debug(" %02x", *c);
 917         pr_debug("\n");
 918
 919         switch (*ext++) {
 920         case 1:         /* Subnet mask */
 921                 if (ic_netmask == NONE)
 922                         memcpy(&ic_netmask, ext+1, 4);
 923                 break;
 924         case 3:         /* Default gateway */
 925                 if (ic_gateway == NONE)
 926                         memcpy(&ic_gateway, ext+1, 4);
 927                 break;
 928         case 6:         /* DNS server */
 929                 servers= *ext/4;
 930                 if (servers > CONF_NAMESERVERS_MAX)
 931                         servers = CONF_NAMESERVERS_MAX;
 932                 for (i = 0; i < servers; i++) {
 933                         if (ic_nameservers[i] == NONE)
 934                                 memcpy(&ic_nameservers[i], ext+1+4*i, 4);
 935                 }
 936                 break;
 937         case 12:        /* Host name */
 938                 if (!ic_host_name_set) {
 939                         ic_bootp_string(utsname()->nodename, ext+1, *ext,
 940                                         __NEW_UTS_LEN);
 941                         ic_host_name_set = 1;
 942                 }
 943                 break;
 944         case 15:        /* Domain name (DNS) */
 945                 if (!ic_domain[0])
 946                         ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
 947                 break;
 948         case 17:        /* Root path */
 949                 if (!root_server_path[0])
 950                         ic_bootp_string(root_server_path, ext+1, *ext,
 951                                         sizeof(root_server_path));
 952                 break;
 953         case 26:        /* Interface MTU */
 954                 memcpy(&mtu, ext+1, sizeof(mtu));
 955                 ic_dev_mtu = ntohs(mtu);
 956                 break;
 957         case 40:        /* NIS Domain name (_not_ DNS) */
 958                 ic_bootp_string(utsname()->domainname, ext+1, *ext,
 959                                 __NEW_UTS_LEN);
 960                 break;
 961         case 42:        /* NTP servers */
 962                 servers = *ext / 4;
 963                 if (servers > CONF_NTP_SERVERS_MAX)
 964                         servers = CONF_NTP_SERVERS_MAX;
 965                 for (i = 0; i < servers; i++) {
 966                         if (ic_ntp_servers[i] == NONE)
 967                                 memcpy(&ic_ntp_servers[i], ext+1+4*i, 4);
 968                 }
 969                 break;
 970         }
 971 }
 972
 973
 974 /*
 975  *  Receive BOOTP reply.
 976  */
 977 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 978 {
 979         struct bootp_pkt *b;
 980         struct iphdr *h;
 981         struct ic_device *d;
 982         int len, ext_len;
 983
 984         if (!net_eq(dev_net(dev), &init_net))
 985                 goto drop;
 986
 987         /* Perform verifications before taking the lock.  */
 988         if (skb->pkt_type == PACKET_OTHERHOST)
 989                 goto drop;
 990
 991         skb = skb_share_check(skb, GFP_ATOMIC);
 992         if (!skb)
 993                 return NET_RX_DROP;
 994
 995         if (!pskb_may_pull(skb,
 996                            sizeof(struct iphdr) +
 997                            sizeof(struct udphdr)))
 998                 goto drop;
 999
1000         b = (struct bootp_pkt *)skb_network_header(skb);
1001         h = &b->iph;
1002
1003         if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
1004                 goto drop;
1005
1006         /* Fragments are not supported */
1007         if (ip_is_fragment(h)) {
1008                 net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
1009                 goto drop;
1010         }
1011
1012         if (skb->len < ntohs(h->tot_len))
1013                 goto drop;
1014
1015         if (ip_fast_csum((char *) h, h->ihl))
1016                 goto drop;
1017
1018         if (b->udph.source != htons(67) || b->udph.dest != htons(68))
1019                 goto drop;
1020
1021         if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
1022                 goto drop;
1023
1024         len = ntohs(b->udph.len) - sizeof(struct udphdr);
1025         ext_len = len - (sizeof(*b) -
1026                          sizeof(struct iphdr) -
1027                          sizeof(struct udphdr) -
1028                          sizeof(b->exten));
1029         if (ext_len < 0)
1030                 goto drop;
1031
1032         /* Ok the front looks good, make sure we can get at the rest.  */
1033         if (!pskb_may_pull(skb, skb->len))
1034                 goto drop;
1035
1036         b = (struct bootp_pkt *)skb_network_header(skb);
1037         h = &b->iph;
1038
1039         /* One reply at a time, please. */
1040         spin_lock(&ic_recv_lock);
1041
1042         /* If we already have a reply, just drop the packet */
1043         if (ic_got_reply)
1044                 goto drop_unlock;
1045
1046         /* Find the ic_device that the packet arrived on */
1047         d = ic_first_dev;
1048         while (d && d->dev != dev)
1049                 d = d->next;
1050         if (!d)
1051                 goto drop_unlock;  /* should never happen */
1052
1053         /* Is it a reply to our BOOTP request? */
1054         if (b->op != BOOTP_REPLY ||
1055             b->xid != d->xid) {
1056                 net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1057                                     d->dev->name, b->op, b->xid);
1058                 goto drop_unlock;
1059         }
1060
1061         /* Parse extensions */
1062         if (ext_len >= 4 &&
1063             !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1064                 u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1065                 u8 *ext;
1066
1067 #ifdef IPCONFIG_DHCP
1068                 if (ic_proto_enabled & IC_USE_DHCP) {
1069                         __be32 server_id = NONE;
1070                         int mt = 0;
1071
1072                         ext = &b->exten[4];
1073                         while (ext < end && *ext != 0xff) {
1074                                 u8 *opt = ext++;
1075                                 if (*opt == 0)  /* Padding */
1076                                         continue;
1077                                 ext += *ext + 1;
1078                                 if (ext >= end)
1079                                         break;
1080                                 switch (*opt) {
1081                                 case 53:        /* Message type */
1082                                         if (opt[1])
1083                                                 mt = opt[2];
1084                                         break;
1085                                 case 54:        /* Server ID (IP address) */
1086                                         if (opt[1] >= 4)
1087                                                 memcpy(&server_id, opt + 2, 4);
1088                                         break;
1089                                 }
1090                         }
1091
1092                         pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1093
1094                         switch (mt) {
1095                         case DHCPOFFER:
1096                                 /* While in the process of accepting one offer,
1097                                  * ignore all others.
1098                                  */
1099                                 if (ic_myaddr != NONE)
1100                                         goto drop_unlock;
1101
1102                                 /* Let's accept that offer. */
1103                                 ic_myaddr = b->your_ip;
1104                                 ic_servaddr = server_id;
1105                                 pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1106                                          &ic_myaddr, &b->iph.saddr);
1107                                 /* The DHCP indicated server address takes
1108                                  * precedence over the bootp header one if
1109                                  * they are different.
1110                                  */
1111                                 if ((server_id != NONE) &&
1112                                     (b->server_ip != server_id))
1113                                         b->server_ip = ic_servaddr;
1114                                 break;
1115
1116                         case DHCPACK:
1117                                 if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1118                                         goto drop_unlock;
1119
1120                                 /* Yeah! */
1121                                 break;
1122
1123                         default:
1124                                 /* Urque.  Forget it*/
1125                                 ic_myaddr = NONE;
1126                                 ic_servaddr = NONE;
1127                                 goto drop_unlock;
1128                         }
1129
1130                         ic_dhcp_msgtype = mt;
1131
1132                 }
1133 #endif /* IPCONFIG_DHCP */
1134
1135                 ext = &b->exten[4];
1136                 while (ext < end && *ext != 0xff) {
1137                         u8 *opt = ext++;
1138                         if (*opt == 0)  /* Padding */
1139                                 continue;
1140                         ext += *ext + 1;
1141                         if (ext < end)
1142                                 ic_do_bootp_ext(opt);
1143                 }
1144         }
1145
1146         /* We have a winner! */
1147         ic_dev = d;
1148         ic_myaddr = b->your_ip;
1149         ic_servaddr = b->server_ip;
1150         ic_addrservaddr = b->iph.saddr;
1151         if (ic_gateway == NONE && b->relay_ip)
1152                 ic_gateway = b->relay_ip;
1153         if (ic_nameservers[0] == NONE)
1154                 ic_nameservers[0] = ic_servaddr;
1155         ic_got_reply = IC_BOOTP;
1156
1157 drop_unlock:
1158         /* Show's over.  Nothing to see here.  */
1159         spin_unlock(&ic_recv_lock);
1160
1161 drop:
1162         /* Throw the packet out. */
1163         kfree_skb(skb);
1164
1165         return 0;
1166 }
1167
1168
1169 #endif
1170
1171
1172 /*
1173  *      Dynamic IP configuration -- DHCP, BOOTP, RARP.
1174  */
1175
1176 #ifdef IPCONFIG_DYNAMIC
1177
1178 static int __init ic_dynamic(void)
1179 {
1180         int retries;
1181         struct ic_device *d;
1182         unsigned long start_jiffies, timeout, jiff;
1183         int do_bootp = ic_proto_have_if & IC_BOOTP;
1184         int do_rarp = ic_proto_have_if & IC_RARP;
1185
1186         /*
1187          * If none of DHCP/BOOTP/RARP was selected, return with an error.
1188          * This routine gets only called when some pieces of information
1189          * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1190          */
1191         if (!ic_proto_enabled) {
1192                 pr_err("IP-Config: Incomplete network configuration information\n");
1193                 return -1;
1194         }
1195
1196 #ifdef IPCONFIG_BOOTP
1197         if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1198                 pr_err("DHCP/BOOTP: No suitable device found\n");
1199 #endif
1200 #ifdef IPCONFIG_RARP
1201         if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1202                 pr_err("RARP: No suitable device found\n");
1203 #endif
1204
1205         if (!ic_proto_have_if)
1206                 /* Error message already printed */
1207                 return -1;
1208
1209         /*
1210          * Setup protocols
1211          */
1212 #ifdef IPCONFIG_BOOTP
1213         if (do_bootp)
1214                 ic_bootp_init();
1215 #endif
1216 #ifdef IPCONFIG_RARP
1217         if (do_rarp)
1218                 ic_rarp_init();
1219 #endif
1220
1221         /*
1222          * Send requests and wait, until we get an answer. This loop
1223          * seems to be a terrible waste of CPU time, but actually there is
1224          * only one process running at all, so we don't need to use any
1225          * scheduler functions.
1226          * [Actually we could now, but the nothing else running note still
1227          *  applies.. - AC]
1228          */
1229         pr_notice("Sending %s%s%s requests .",
1230                   do_bootp
1231                   ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1232                   (do_bootp && do_rarp) ? " and " : "",
1233                   do_rarp ? "RARP" : "");
1234
1235         start_jiffies = jiffies;
1236         d = ic_first_dev;
1237         retries = CONF_SEND_RETRIES;
1238         get_random_bytes(&timeout, sizeof(timeout));
1239         timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1240         for (;;) {
1241 #ifdef IPCONFIG_BOOTP
1242                 if (do_bootp && (d->able & IC_BOOTP))
1243                         ic_bootp_send_if(d, jiffies - start_jiffies);
1244 #endif
1245 #ifdef IPCONFIG_RARP
1246                 if (do_rarp && (d->able & IC_RARP))
1247                         ic_rarp_send_if(d);
1248 #endif
1249
1250                 if (!d->next) {
1251                         jiff = jiffies + timeout;
1252                         while (time_before(jiffies, jiff) && !ic_got_reply)
1253                                 schedule_timeout_uninterruptible(1);
1254                 }
1255 #ifdef IPCONFIG_DHCP
1256                 /* DHCP isn't done until we get a DHCPACK. */
1257                 if ((ic_got_reply & IC_BOOTP) &&
1258                     (ic_proto_enabled & IC_USE_DHCP) &&
1259                     ic_dhcp_msgtype != DHCPACK) {
1260                         ic_got_reply = 0;
1261                         /* continue on device that got the reply */
1262                         d = ic_dev;
1263                         pr_cont(",");
1264                         continue;
1265                 }
1266 #endif /* IPCONFIG_DHCP */
1267
1268                 if (ic_got_reply) {
1269                         pr_cont(" OK\n");
1270                         break;
1271                 }
1272
1273                 if ((d = d->next))
1274                         continue;
1275
1276                 if (! --retries) {
1277                         pr_cont(" timed out!\n");
1278                         break;
1279                 }
1280
1281                 d = ic_first_dev;
1282
1283                 timeout = timeout CONF_TIMEOUT_MULT;
1284                 if (timeout > CONF_TIMEOUT_MAX)
1285                         timeout = CONF_TIMEOUT_MAX;
1286
1287                 pr_cont(".");
1288         }
1289
1290 #ifdef IPCONFIG_BOOTP
1291         if (do_bootp)
1292                 ic_bootp_cleanup();
1293 #endif
1294 #ifdef IPCONFIG_RARP
1295         if (do_rarp)
1296                 ic_rarp_cleanup();
1297 #endif
1298
1299         if (!ic_got_reply) {
1300                 ic_myaddr = NONE;
1301                 return -1;
1302         }
1303
1304         pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1305                 ((ic_got_reply & IC_RARP) ? "RARP"
1306                 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1307                 &ic_addrservaddr, &ic_myaddr);
1308
1309         return 0;
1310 }
1311
1312 #endif /* IPCONFIG_DYNAMIC */
1313
1314 #ifdef CONFIG_PROC_FS
1315 /* proc_dir_entry for /proc/net/ipconfig */
1316 static struct proc_dir_entry *ipconfig_dir;
1317
1318 /* Name servers: */
1319 static int pnp_seq_show(struct seq_file *seq, void *v)
1320 {
1321         int i;
1322
1323         if (ic_proto_used & IC_PROTO)
1324                 seq_printf(seq, "#PROTO: %s\n",
1325                            (ic_proto_used & IC_RARP) ? "RARP"
1326                            : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1327         else
1328                 seq_puts(seq, "#MANUAL\n");
1329
1330         if (ic_domain[0])
1331                 seq_printf(seq,
1332                            "domain %s\n", ic_domain);
1333         for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1334                 if (ic_nameservers[i] != NONE)
1335                         seq_printf(seq, "nameserver %pI4\n",
1336                                    &ic_nameservers[i]);
1337         }
1338         if (ic_servaddr != NONE)
1339                 seq_printf(seq, "bootserver %pI4\n",
1340                            &ic_servaddr);
1341         return 0;
1342 }
1343
1344 /* Create the /proc/net/ipconfig directory */
1345 static int __init ipconfig_proc_net_init(void)
1346 {
1347         ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net);
1348         if (!ipconfig_dir)
1349                 return -ENOMEM;
1350
1351         return 0;
1352 }
1353
1354 /* Create a new file under /proc/net/ipconfig */
1355 static int ipconfig_proc_net_create(const char *name,
1356                                     const struct proc_ops *proc_ops)
1357 {
1358         char *pname;
1359         struct proc_dir_entry *p;
1360
1361         if (!ipconfig_dir)
1362                 return -ENOMEM;
1363
1364         pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name);
1365         if (!pname)
1366                 return -ENOMEM;
1367
1368         p = proc_create(pname, 0444, init_net.proc_net, proc_ops);
1369         kfree(pname);
1370         if (!p)
1371                 return -ENOMEM;
1372
1373         return 0;
1374 }
1375
1376 /* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */
1377 static int ntp_servers_show(struct seq_file *seq, void *v)
1378 {
1379         int i;
1380
1381         for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1382                 if (ic_ntp_servers[i] != NONE)
1383                         seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]);
1384         }
1385         return 0;
1386 }
1387 DEFINE_PROC_SHOW_ATTRIBUTE(ntp_servers);
1388 #endif /* CONFIG_PROC_FS */
1389
1390 /*
1391  *  Extract IP address from the parameter string if needed. Note that we
1392  *  need to have root_server_addr set _before_ IPConfig gets called as it
1393  *  can override it.
1394  */
1395 __be32 __init root_nfs_parse_addr(char *name)
1396 {
1397         __be32 addr;
1398         int octets = 0;
1399         char *cp, *cq;
1400
1401         cp = cq = name;
1402         while (octets < 4) {
1403                 while (*cp >= '0' && *cp <= '9')
1404                         cp++;
1405                 if (cp == cq || cp - cq > 3)
1406                         break;
1407                 if (*cp == '.' || octets == 3)
1408                         octets++;
1409                 if (octets < 4)
1410                         cp++;
1411                 cq = cp;
1412         }
1413         if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1414                 if (*cp == ':')
1415                         *cp++ = '\0';
1416                 addr = in_aton(name);
1417                 memmove(name, cp, strlen(cp) + 1);
1418         } else
1419                 addr = NONE;
1420
1421         return addr;
1422 }
1423
1424 #define DEVICE_WAIT_MAX         12 /* 12 seconds */
1425
1426 static int __init wait_for_devices(void)
1427 {
1428         int i;
1429
1430         for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1431                 struct net_device *dev;
1432                 int found = 0;
1433
1434                 /* make sure deferred device probes are finished */
1435                 wait_for_device_probe();
1436
1437                 rtnl_lock();
1438                 for_each_netdev(&init_net, dev) {
1439                         if (ic_is_init_dev(dev)) {
1440                                 found = 1;
1441                                 break;
1442                         }
1443                 }
1444                 rtnl_unlock();
1445                 if (found)
1446                         return 0;
1447                 ssleep(1);
1448         }
1449         return -ENODEV;
1450 }
1451
1452 /*
1453  *      IP Autoconfig dispatcher.
1454  */
1455
1456 static int __init ip_auto_config(void)
1457 {
1458         __be32 addr;
1459 #ifdef IPCONFIG_DYNAMIC
1460         int retries = CONF_OPEN_RETRIES;
1461 #endif
1462         int err;
1463         unsigned int i, count;
1464
1465         /* Initialise all name servers and NTP servers to NONE (but only if the
1466          * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded,
1467          * otherwise we'll overwrite the IP addresses specified there)
1468          */
1469         if (ic_set_manually == 0) {
1470                 ic_nameservers_predef();
1471                 ic_ntp_servers_predef();
1472         }
1473
1474 #ifdef CONFIG_PROC_FS
1475         proc_create_single("pnp", 0444, init_net.proc_net, pnp_seq_show);
1476
1477         if (ipconfig_proc_net_init() == 0)
1478                 ipconfig_proc_net_create("ntp_servers", &ntp_servers_proc_ops);
1479 #endif /* CONFIG_PROC_FS */
1480
1481         if (!ic_enable)
1482                 return 0;
1483
1484         pr_debug("IP-Config: Entered.\n");
1485 #ifdef IPCONFIG_DYNAMIC
1486  try_try_again:
1487 #endif
1488         /* Wait for devices to appear */
1489         err = wait_for_devices();
1490         if (err)
1491                 return err;
1492
1493         /* Setup all network devices */
1494         err = ic_open_devs();
1495         if (err)
1496                 return err;
1497
1498         /* Give drivers a chance to settle */
1499         msleep(CONF_POST_OPEN);
1500
1501         /*
1502          * If the config information is insufficient (e.g., our IP address or
1503          * IP address of the boot server is missing or we have multiple network
1504          * interfaces and no default was set), use BOOTP or RARP to get the
1505          * missing values.
1506          */
1507         if (ic_myaddr == NONE ||
1508 #if defined(CONFIG_ROOT_NFS) || defined(CONFIG_CIFS_ROOT)
1509             (root_server_addr == NONE &&
1510              ic_servaddr == NONE &&
1511              (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) ||
1512 #endif
1513             ic_first_dev->next) {
1514 #ifdef IPCONFIG_DYNAMIC
1515                 if (ic_dynamic() < 0) {
1516                         ic_close_devs();
1517
1518                         /*
1519                          * I don't know why, but sometimes the
1520                          * eepro100 driver (at least) gets upset and
1521                          * doesn't work the first time it's opened.
1522                          * But then if you close it and reopen it, it
1523                          * works just fine.  So we need to try that at
1524                          * least once before giving up.
1525                          *
1526                          * Also, if the root will be NFS-mounted, we
1527                          * have nowhere to go if DHCP fails.  So we
1528                          * just have to keep trying forever.
1529                          *
1530                          *                              -- Chip
1531                          */
1532 #ifdef CONFIG_ROOT_NFS
1533                         if (ROOT_DEV ==  Root_NFS) {
1534                                 pr_err("IP-Config: Retrying forever (NFS root)...\n");
1535                                 goto try_try_again;
1536                         }
1537 #endif
1538 #ifdef CONFIG_CIFS_ROOT
1539                         if (ROOT_DEV == Root_CIFS) {
1540                                 pr_err("IP-Config: Retrying forever (CIFS root)...\n");
1541                                 goto try_try_again;
1542                         }
1543 #endif
1544
1545                         if (--retries) {
1546                                 pr_err("IP-Config: Reopening network devices...\n");
1547                                 goto try_try_again;
1548                         }
1549
1550                         /* Oh, well.  At least we tried. */
1551                         pr_err("IP-Config: Auto-configuration of network failed\n");
1552                         return -1;
1553                 }
1554 #else /* !DYNAMIC */
1555                 pr_err("IP-Config: Incomplete network configuration information\n");
1556                 ic_close_devs();
1557                 return -1;
1558 #endif /* IPCONFIG_DYNAMIC */
1559         } else {
1560                 /* Device selected manually or only one device -> use it */
1561                 ic_dev = ic_first_dev;
1562         }
1563
1564         addr = root_nfs_parse_addr(root_server_path);
1565         if (root_server_addr == NONE)
1566                 root_server_addr = addr;
1567
1568         /*
1569          * Use defaults wherever applicable.
1570          */
1571         if (ic_defaults() < 0)
1572                 return -1;
1573
1574         /*
1575          * Record which protocol was actually used.
1576          */
1577 #ifdef IPCONFIG_DYNAMIC
1578         ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1579 #endif
1580
1581 #ifndef IPCONFIG_SILENT
1582         /*
1583          * Clue in the operator.
1584          */
1585         pr_info("IP-Config: Complete:\n");
1586
1587         pr_info("     device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1588                 ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1589                 &ic_myaddr, &ic_netmask, &ic_gateway);
1590         pr_info("     host=%s, domain=%s, nis-domain=%s\n",
1591                 utsname()->nodename, ic_domain, utsname()->domainname);
1592         pr_info("     bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1593                 &ic_servaddr, &root_server_addr, root_server_path);
1594         if (ic_dev_mtu)
1595                 pr_cont(", mtu=%d", ic_dev_mtu);
1596         /* Name servers (if any): */
1597         for (i = 0, count = 0; i < CONF_NAMESERVERS_MAX; i++) {
1598                 if (ic_nameservers[i] != NONE) {
1599                         if (i == 0)
1600                                 pr_info("     nameserver%u=%pI4",
1601                                         i, &ic_nameservers[i]);
1602                         else
1603                                 pr_cont(", nameserver%u=%pI4",
1604                                         i, &ic_nameservers[i]);
1605
1606                         count++;
1607                 }
1608                 if ((i + 1 == CONF_NAMESERVERS_MAX) && count > 0)
1609                         pr_cont("\n");
1610         }
1611         /* NTP servers (if any): */
1612         for (i = 0, count = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1613                 if (ic_ntp_servers[i] != NONE) {
1614                         if (i == 0)
1615                                 pr_info("     ntpserver%u=%pI4",
1616                                         i, &ic_ntp_servers[i]);
1617                         else
1618                                 pr_cont(", ntpserver%u=%pI4",
1619                                         i, &ic_ntp_servers[i]);
1620
1621                         count++;
1622                 }
1623                 if ((i + 1 == CONF_NTP_SERVERS_MAX) && count > 0)
1624                         pr_cont("\n");
1625         }
1626 #endif /* !SILENT */
1627
1628         /*
1629          * Close all network devices except the device we've
1630          * autoconfigured and set up routes.
1631          */
1632         if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1633                 err = -1;
1634         else
1635                 err = 0;
1636
1637         ic_close_devs();
1638
1639         return err;
1640 }
1641
1642 late_initcall(ip_auto_config);
1643
1644
1645 /*
1646  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1647  *  command line parameter.  See Documentation/admin-guide/nfs/nfsroot.rst.
1648  */
1649 static int __init ic_proto_name(char *name)
1650 {
1651         if (!strcmp(name, "on") || !strcmp(name, "any")) {
1652                 return 1;
1653         }
1654         if (!strcmp(name, "off") || !strcmp(name, "none")) {
1655                 return 0;
1656         }
1657 #ifdef CONFIG_IP_PNP_DHCP
1658         else if (!strncmp(name, "dhcp", 4)) {
1659                 char *client_id;
1660
1661                 ic_proto_enabled &= ~IC_RARP;
1662                 client_id = strstr(name, "dhcp,");
1663                 if (client_id) {
1664                         char *v;
1665
1666                         client_id = client_id + 5;
1667                         v = strchr(client_id, ',');
1668                         if (!v)
1669                                 return 1;
1670                         *v = 0;
1671                         if (kstrtou8(client_id, 0, dhcp_client_identifier))
1672                                 pr_debug("DHCP: Invalid client identifier type\n");
1673                         strncpy(dhcp_client_identifier + 1, v + 1, 251);
1674                         *v = ',';
1675                 }
1676                 return 1;
1677         }
1678 #endif
1679 #ifdef CONFIG_IP_PNP_BOOTP
1680         else if (!strcmp(name, "bootp")) {
1681                 ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1682                 return 1;
1683         }
1684 #endif
1685 #ifdef CONFIG_IP_PNP_RARP
1686         else if (!strcmp(name, "rarp")) {
1687                 ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1688                 return 1;
1689         }
1690 #endif
1691 #ifdef IPCONFIG_DYNAMIC
1692         else if (!strcmp(name, "both")) {
1693                 ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1694                 return 1;
1695         }
1696 #endif
1697         return 0;
1698 }
1699
1700 static int __init ip_auto_config_setup(char *addrs)
1701 {
1702         char *cp, *ip, *dp;
1703         int num = 0;
1704
1705         ic_set_manually = 1;
1706         ic_enable = 1;
1707
1708         /*
1709          * If any dhcp, bootp etc options are set, leave autoconfig on
1710          * and skip the below static IP processing.
1711          */
1712         if (ic_proto_name(addrs))
1713                 return 1;
1714
1715         /* If no static IP is given, turn off autoconfig and bail.  */
1716         if (*addrs == 0 ||
1717             strcmp(addrs, "off") == 0 ||
1718             strcmp(addrs, "none") == 0) {
1719                 ic_enable = 0;
1720                 return 1;
1721         }
1722
1723         /* Initialise all name servers and NTP servers to NONE */
1724         ic_nameservers_predef();
1725         ic_ntp_servers_predef();
1726
1727         /* Parse string for static IP assignment.  */
1728         ip = addrs;
1729         while (ip && *ip) {
1730                 if ((cp = strchr(ip, ':')))
1731                         *cp++ = '\0';
1732                 if (strlen(ip) > 0) {
1733                         pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1734                         switch (num) {
1735                         case 0:
1736                                 if ((ic_myaddr = in_aton(ip)) == ANY)
1737                                         ic_myaddr = NONE;
1738                                 break;
1739                         case 1:
1740                                 if ((ic_servaddr = in_aton(ip)) == ANY)
1741                                         ic_servaddr = NONE;
1742                                 break;
1743                         case 2:
1744                                 if ((ic_gateway = in_aton(ip)) == ANY)
1745                                         ic_gateway = NONE;
1746                                 break;
1747                         case 3:
1748                                 if ((ic_netmask = in_aton(ip)) == ANY)
1749                                         ic_netmask = NONE;
1750                                 break;
1751                         case 4:
1752                                 if ((dp = strchr(ip, '.'))) {
1753                                         *dp++ = '\0';
1754                                         strlcpy(utsname()->domainname, dp,
1755                                                 sizeof(utsname()->domainname));
1756                                 }
1757                                 strlcpy(utsname()->nodename, ip,
1758                                         sizeof(utsname()->nodename));
1759                                 ic_host_name_set = 1;
1760                                 break;
1761                         case 5:
1762                                 strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1763                                 break;
1764                         case 6:
1765                                 if (ic_proto_name(ip) == 0 &&
1766                                     ic_myaddr == NONE) {
1767                                         ic_enable = 0;
1768                                 }
1769                                 break;
1770                         case 7:
1771                                 if (CONF_NAMESERVERS_MAX >= 1) {
1772                                         ic_nameservers[0] = in_aton(ip);
1773                                         if (ic_nameservers[0] == ANY)
1774                                                 ic_nameservers[0] = NONE;
1775                                 }
1776                                 break;
1777                         case 8:
1778                                 if (CONF_NAMESERVERS_MAX >= 2) {
1779                                         ic_nameservers[1] = in_aton(ip);
1780                                         if (ic_nameservers[1] == ANY)
1781                                                 ic_nameservers[1] = NONE;
1782                                 }
1783                                 break;
1784                         case 9:
1785                                 if (CONF_NTP_SERVERS_MAX >= 1) {
1786                                         ic_ntp_servers[0] = in_aton(ip);
1787                                         if (ic_ntp_servers[0] == ANY)
1788                                                 ic_ntp_servers[0] = NONE;
1789                                 }
1790                                 break;
1791                         }
1792                 }
1793                 ip = cp;
1794                 num++;
1795         }
1796
1797         return 1;
1798 }
1799 __setup("ip=", ip_auto_config_setup);
1800
1801 static int __init nfsaddrs_config_setup(char *addrs)
1802 {
1803         return ip_auto_config_setup(addrs);
1804 }
1805 __setup("nfsaddrs=", nfsaddrs_config_setup);
1806
1807 static int __init vendor_class_identifier_setup(char *addrs)
1808 {
1809         if (strlcpy(vendor_class_identifier, addrs,
1810                     sizeof(vendor_class_identifier))
1811             >= sizeof(vendor_class_identifier))
1812                 pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1813                         vendor_class_identifier);
1814         return 1;
1815 }
1816 __setup("dhcpclass=", vendor_class_identifier_setup);
1817
1818 static int __init set_carrier_timeout(char *str)
1819 {
1820         ssize_t ret;
1821
1822         if (!str)
1823                 return 0;
1824
1825         ret = kstrtouint(str, 0, &carrier_timeout);
1826         if (ret)
1827                 return 0;
1828
1829         return 1;
1830 }
1831 __setup("carrier_timeout=", set_carrier_timeout);