linux/net/ipv4/ipconfig.c
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   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/dsa.h>
  65#include <net/ip.h>
  66#include <net/ipconfig.h>
  67#include <net/route.h>
  68
  69#include <linux/uaccess.h>
  70#include <net/checksum.h>
  71#include <asm/processor.h>
  72
  73#if defined(CONFIG_IP_PNP_DHCP)
  74#define IPCONFIG_DHCP
  75#endif
  76#if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
  77#define IPCONFIG_BOOTP
  78#endif
  79#if defined(CONFIG_IP_PNP_RARP)
  80#define IPCONFIG_RARP
  81#endif
  82#if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
  83#define IPCONFIG_DYNAMIC
  84#endif
  85
  86/* Define the friendly delay before and after opening net devices */
  87#define CONF_POST_OPEN          10      /* After opening: 10 msecs */
  88
  89/* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
  90#define CONF_OPEN_RETRIES       2       /* (Re)open devices twice */
  91#define CONF_SEND_RETRIES       6       /* Send six requests per open */
  92#define CONF_BASE_TIMEOUT       (HZ*2)  /* Initial timeout: 2 seconds */
  93#define CONF_TIMEOUT_RANDOM     (HZ)    /* Maximum amount of randomization */
  94#define CONF_TIMEOUT_MULT       *7/4    /* Rate of timeout growth */
  95#define CONF_TIMEOUT_MAX        (HZ*30) /* Maximum allowed timeout */
  96#define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
  97                                           - '3' from resolv.h */
  98#define CONF_NTP_SERVERS_MAX   3        /* Maximum number of NTP servers */
  99
 100#define NONE cpu_to_be32(INADDR_NONE)
 101#define ANY cpu_to_be32(INADDR_ANY)
 102
 103/* Wait for carrier timeout default in seconds */
 104static unsigned int carrier_timeout = 120;
 105
 106/*
 107 * Public IP configuration
 108 */
 109
 110/* This is used by platforms which might be able to set the ipconfig
 111 * variables using firmware environment vars.  If this is set, it will
 112 * ignore such firmware variables.
 113 */
 114int ic_set_manually __initdata = 0;             /* IPconfig parameters set manually */
 115
 116static int ic_enable __initdata;                /* IP config enabled? */
 117
 118/* Protocol choice */
 119int ic_proto_enabled __initdata = 0
 120#ifdef IPCONFIG_BOOTP
 121                        | IC_BOOTP
 122#endif
 123#ifdef CONFIG_IP_PNP_DHCP
 124                        | IC_USE_DHCP
 125#endif
 126#ifdef IPCONFIG_RARP
 127                        | IC_RARP
 128#endif
 129                        ;
 130
 131static int ic_host_name_set __initdata; /* Host name set by us? */
 132
 133__be32 ic_myaddr = NONE;                /* My IP address */
 134static __be32 ic_netmask = NONE;        /* Netmask for local subnet */
 135__be32 ic_gateway = NONE;       /* Gateway IP address */
 136
 137#ifdef IPCONFIG_DYNAMIC
 138static __be32 ic_addrservaddr = NONE;   /* IP Address of the IP addresses'server */
 139#endif
 140
 141__be32 ic_servaddr = NONE;      /* Boot server IP address */
 142
 143__be32 root_server_addr = NONE; /* Address of NFS server */
 144u8 root_server_path[256] = { 0, };      /* Path to mount as root */
 145
 146/* vendor class identifier */
 147static char vendor_class_identifier[253] __initdata;
 148
 149#if defined(CONFIG_IP_PNP_DHCP)
 150static char dhcp_client_identifier[253] __initdata;
 151#endif
 152
 153/* Persistent data: */
 154
 155#ifdef IPCONFIG_DYNAMIC
 156static int ic_proto_used;                       /* Protocol used, if any */
 157#else
 158#define ic_proto_used 0
 159#endif
 160static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
 161static __be32 ic_ntp_servers[CONF_NTP_SERVERS_MAX]; /* NTP server IP addresses */
 162static u8 ic_domain[64];                /* DNS (not NIS) domain name */
 163
 164/*
 165 * Private state.
 166 */
 167
 168/* Name of user-selected boot device */
 169static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
 170
 171/* Protocols supported by available interfaces */
 172static int ic_proto_have_if __initdata;
 173
 174/* MTU for boot device */
 175static int ic_dev_mtu __initdata;
 176
 177#ifdef IPCONFIG_DYNAMIC
 178static DEFINE_SPINLOCK(ic_recv_lock);
 179static volatile int ic_got_reply __initdata;    /* Proto(s) that replied */
 180#endif
 181#ifdef IPCONFIG_DHCP
 182static int ic_dhcp_msgtype __initdata;  /* DHCP msg type received */
 183#endif
 184
 185
 186/*
 187 *      Network devices
 188 */
 189
 190struct ic_device {
 191        struct ic_device *next;
 192        struct net_device *dev;
 193        unsigned short flags;
 194        short able;
 195        __be32 xid;
 196};
 197
 198static struct ic_device *ic_first_dev __initdata;       /* List of open device */
 199static struct ic_device *ic_dev __initdata;             /* Selected device */
 200
 201static bool __init ic_is_init_dev(struct net_device *dev)
 202{
 203        if (dev->flags & IFF_LOOPBACK)
 204                return false;
 205        return user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
 206            (!(dev->flags & IFF_LOOPBACK) &&
 207             (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
 208             strncmp(dev->name, "dummy", 5));
 209}
 210
 211static int __init ic_open_devs(void)
 212{
 213        struct ic_device *d, **last;
 214        struct net_device *dev;
 215        unsigned short oflags;
 216        unsigned long start, next_msg;
 217
 218        last = &ic_first_dev;
 219        rtnl_lock();
 220
 221        /* bring loopback and DSA master network devices up first */
 222        for_each_netdev(&init_net, dev) {
 223                if (!(dev->flags & IFF_LOOPBACK) && !netdev_uses_dsa(dev))
 224                        continue;
 225                if (dev_change_flags(dev, dev->flags | IFF_UP, NULL) < 0)
 226                        pr_err("IP-Config: Failed to open %s\n", dev->name);
 227        }
 228
 229        for_each_netdev(&init_net, dev) {
 230                if (ic_is_init_dev(dev)) {
 231                        int able = 0;
 232                        if (dev->mtu >= 364)
 233                                able |= IC_BOOTP;
 234                        else
 235                                pr_warn("DHCP/BOOTP: Ignoring device %s, MTU %d too small\n",
 236                                        dev->name, dev->mtu);
 237                        if (!(dev->flags & IFF_NOARP))
 238                                able |= IC_RARP;
 239                        able &= ic_proto_enabled;
 240                        if (ic_proto_enabled && !able)
 241                                continue;
 242                        oflags = dev->flags;
 243                        if (dev_change_flags(dev, oflags | IFF_UP, NULL) < 0) {
 244                                pr_err("IP-Config: Failed to open %s\n",
 245                                       dev->name);
 246                                continue;
 247                        }
 248                        if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
 249                                rtnl_unlock();
 250                                return -ENOMEM;
 251                        }
 252                        d->dev = dev;
 253                        *last = d;
 254                        last = &d->next;
 255                        d->flags = oflags;
 256                        d->able = able;
 257                        if (able & IC_BOOTP)
 258                                get_random_bytes(&d->xid, sizeof(__be32));
 259                        else
 260                                d->xid = 0;
 261                        ic_proto_have_if |= able;
 262                        pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n",
 263                                 dev->name, able, d->xid);
 264                }
 265        }
 266
 267        /* no point in waiting if we could not bring up at least one device */
 268        if (!ic_first_dev)
 269                goto have_carrier;
 270
 271        /* wait for a carrier on at least one device */
 272        start = jiffies;
 273        next_msg = start + msecs_to_jiffies(20000);
 274        while (time_before(jiffies, start +
 275                           msecs_to_jiffies(carrier_timeout * 1000))) {
 276                int wait, elapsed;
 277
 278                for_each_netdev(&init_net, dev)
 279                        if (ic_is_init_dev(dev) && netif_carrier_ok(dev))
 280                                goto have_carrier;
 281
 282                msleep(1);
 283
 284                if (time_before(jiffies, next_msg))
 285                        continue;
 286
 287                elapsed = jiffies_to_msecs(jiffies - start);
 288                wait = (carrier_timeout * 1000 - elapsed + 500) / 1000;
 289                pr_info("Waiting up to %d more seconds for network.\n", wait);
 290                next_msg = jiffies + msecs_to_jiffies(20000);
 291        }
 292have_carrier:
 293        rtnl_unlock();
 294
 295        *last = NULL;
 296
 297        if (!ic_first_dev) {
 298                if (user_dev_name[0])
 299                        pr_err("IP-Config: Device `%s' not found\n",
 300                               user_dev_name);
 301                else
 302                        pr_err("IP-Config: No network devices available\n");
 303                return -ENODEV;
 304        }
 305        return 0;
 306}
 307
 308static void __init ic_close_devs(void)
 309{
 310        struct ic_device *d, *next;
 311        struct net_device *dev;
 312
 313        rtnl_lock();
 314        next = ic_first_dev;
 315        while ((d = next)) {
 316                next = d->next;
 317                dev = d->dev;
 318                if (d != ic_dev && !netdev_uses_dsa(dev)) {
 319                        pr_debug("IP-Config: Downing %s\n", dev->name);
 320                        dev_change_flags(dev, d->flags, NULL);
 321                }
 322                kfree(d);
 323        }
 324        rtnl_unlock();
 325}
 326
 327/*
 328 *      Interface to various network functions.
 329 */
 330
 331static inline void
 332set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
 333{
 334        sin->sin_family = AF_INET;
 335        sin->sin_addr.s_addr = addr;
 336        sin->sin_port = port;
 337}
 338
 339/*
 340 *      Set up interface addresses and routes.
 341 */
 342
 343static int __init ic_setup_if(void)
 344{
 345        struct ifreq ir;
 346        struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
 347        int err;
 348
 349        memset(&ir, 0, sizeof(ir));
 350        strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name);
 351        set_sockaddr(sin, ic_myaddr, 0);
 352        if ((err = devinet_ioctl(&init_net, SIOCSIFADDR, &ir)) < 0) {
 353                pr_err("IP-Config: Unable to set interface address (%d)\n",
 354                       err);
 355                return -1;
 356        }
 357        set_sockaddr(sin, ic_netmask, 0);
 358        if ((err = devinet_ioctl(&init_net, SIOCSIFNETMASK, &ir)) < 0) {
 359                pr_err("IP-Config: Unable to set interface netmask (%d)\n",
 360                       err);
 361                return -1;
 362        }
 363        set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
 364        if ((err = devinet_ioctl(&init_net, SIOCSIFBRDADDR, &ir)) < 0) {
 365                pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
 366                       err);
 367                return -1;
 368        }
 369        /* Handle the case where we need non-standard MTU on the boot link (a network
 370         * using jumbo frames, for instance).  If we can't set the mtu, don't error
 371         * out, we'll try to muddle along.
 372         */
 373        if (ic_dev_mtu != 0) {
 374                rtnl_lock();
 375                if ((err = dev_set_mtu(ic_dev->dev, ic_dev_mtu)) < 0)
 376                        pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
 377                               ic_dev_mtu, err);
 378                rtnl_unlock();
 379        }
 380        return 0;
 381}
 382
 383static int __init ic_setup_routes(void)
 384{
 385        /* No need to setup device routes, only the default route... */
 386
 387        if (ic_gateway != NONE) {
 388                struct rtentry rm;
 389                int err;
 390
 391                memset(&rm, 0, sizeof(rm));
 392                if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
 393                        pr_err("IP-Config: Gateway not on directly connected network\n");
 394                        return -1;
 395                }
 396                set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
 397                set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
 398                set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
 399                rm.rt_flags = RTF_UP | RTF_GATEWAY;
 400                if ((err = ip_rt_ioctl(&init_net, SIOCADDRT, &rm)) < 0) {
 401                        pr_err("IP-Config: Cannot add default route (%d)\n",
 402                               err);
 403                        return -1;
 404                }
 405        }
 406
 407        return 0;
 408}
 409
 410/*
 411 *      Fill in default values for all missing parameters.
 412 */
 413
 414static int __init ic_defaults(void)
 415{
 416        /*
 417         *      At this point we have no userspace running so need not
 418         *      claim locks on system_utsname
 419         */
 420
 421        if (!ic_host_name_set)
 422                sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
 423
 424        if (root_server_addr == NONE)
 425                root_server_addr = ic_servaddr;
 426
 427        if (ic_netmask == NONE) {
 428                if (IN_CLASSA(ntohl(ic_myaddr)))
 429                        ic_netmask = htonl(IN_CLASSA_NET);
 430                else if (IN_CLASSB(ntohl(ic_myaddr)))
 431                        ic_netmask = htonl(IN_CLASSB_NET);
 432                else if (IN_CLASSC(ntohl(ic_myaddr)))
 433                        ic_netmask = htonl(IN_CLASSC_NET);
 434                else if (IN_CLASSE(ntohl(ic_myaddr)))
 435                        ic_netmask = htonl(IN_CLASSE_NET);
 436                else {
 437                        pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
 438                               &ic_myaddr);
 439                        return -1;
 440                }
 441                pr_notice("IP-Config: Guessing netmask %pI4\n",
 442                          &ic_netmask);
 443        }
 444
 445        return 0;
 446}
 447
 448/*
 449 *      RARP support.
 450 */
 451
 452#ifdef IPCONFIG_RARP
 453
 454static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
 455
 456static struct packet_type rarp_packet_type __initdata = {
 457        .type = cpu_to_be16(ETH_P_RARP),
 458        .func = ic_rarp_recv,
 459};
 460
 461static inline void __init ic_rarp_init(void)
 462{
 463        dev_add_pack(&rarp_packet_type);
 464}
 465
 466static inline void __init ic_rarp_cleanup(void)
 467{
 468        dev_remove_pack(&rarp_packet_type);
 469}
 470
 471/*
 472 *  Process received RARP packet.
 473 */
 474static int __init
 475ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 476{
 477        struct arphdr *rarp;
 478        unsigned char *rarp_ptr;
 479        __be32 sip, tip;
 480        unsigned char *tha;             /* t for "target" */
 481        struct ic_device *d;
 482
 483        if (!net_eq(dev_net(dev), &init_net))
 484                goto drop;
 485
 486        skb = skb_share_check(skb, GFP_ATOMIC);
 487        if (!skb)
 488                return NET_RX_DROP;
 489
 490        if (!pskb_may_pull(skb, sizeof(struct arphdr)))
 491                goto drop;
 492
 493        /* Basic sanity checks can be done without the lock.  */
 494        rarp = (struct arphdr *)skb_transport_header(skb);
 495
 496        /* If this test doesn't pass, it's not IP, or we should
 497         * ignore it anyway.
 498         */
 499        if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
 500                goto drop;
 501
 502        /* If it's not a RARP reply, delete it. */
 503        if (rarp->ar_op != htons(ARPOP_RREPLY))
 504                goto drop;
 505
 506        /* If it's not Ethernet, delete it. */
 507        if (rarp->ar_pro != htons(ETH_P_IP))
 508                goto drop;
 509
 510        if (!pskb_may_pull(skb, arp_hdr_len(dev)))
 511                goto drop;
 512
 513        /* OK, it is all there and looks valid, process... */
 514        rarp = (struct arphdr *)skb_transport_header(skb);
 515        rarp_ptr = (unsigned char *) (rarp + 1);
 516
 517        /* One reply at a time, please. */
 518        spin_lock(&ic_recv_lock);
 519
 520        /* If we already have a reply, just drop the packet */
 521        if (ic_got_reply)
 522                goto drop_unlock;
 523
 524        /* Find the ic_device that the packet arrived on */
 525        d = ic_first_dev;
 526        while (d && d->dev != dev)
 527                d = d->next;
 528        if (!d)
 529                goto drop_unlock;       /* should never happen */
 530
 531        /* Extract variable-width fields */
 532        rarp_ptr += dev->addr_len;
 533        memcpy(&sip, rarp_ptr, 4);
 534        rarp_ptr += 4;
 535        tha = rarp_ptr;
 536        rarp_ptr += dev->addr_len;
 537        memcpy(&tip, rarp_ptr, 4);
 538
 539        /* Discard packets which are not meant for us. */
 540        if (memcmp(tha, dev->dev_addr, dev->addr_len))
 541                goto drop_unlock;
 542
 543        /* Discard packets which are not from specified server. */
 544        if (ic_servaddr != NONE && ic_servaddr != sip)
 545                goto drop_unlock;
 546
 547        /* We have a winner! */
 548        ic_dev = d;
 549        if (ic_myaddr == NONE)
 550                ic_myaddr = tip;
 551        ic_servaddr = sip;
 552        ic_addrservaddr = sip;
 553        ic_got_reply = IC_RARP;
 554
 555drop_unlock:
 556        /* Show's over.  Nothing to see here.  */
 557        spin_unlock(&ic_recv_lock);
 558
 559drop:
 560        /* Throw the packet out. */
 561        kfree_skb(skb);
 562        return 0;
 563}
 564
 565
 566/*
 567 *  Send RARP request packet over a single interface.
 568 */
 569static void __init ic_rarp_send_if(struct ic_device *d)
 570{
 571        struct net_device *dev = d->dev;
 572        arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
 573                 dev->dev_addr, dev->dev_addr);
 574}
 575#endif
 576
 577/*
 578 *  Predefine Nameservers
 579 */
 580static inline void __init ic_nameservers_predef(void)
 581{
 582        int i;
 583
 584        for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
 585                ic_nameservers[i] = NONE;
 586}
 587
 588/* Predefine NTP servers */
 589static inline void __init ic_ntp_servers_predef(void)
 590{
 591        int i;
 592
 593        for (i = 0; i < CONF_NTP_SERVERS_MAX; i++)
 594                ic_ntp_servers[i] = NONE;
 595}
 596
 597/*
 598 *      DHCP/BOOTP support.
 599 */
 600
 601#ifdef IPCONFIG_BOOTP
 602
 603struct bootp_pkt {              /* BOOTP packet format */
 604        struct iphdr iph;       /* IP header */
 605        struct udphdr udph;     /* UDP header */
 606        u8 op;                  /* 1=request, 2=reply */
 607        u8 htype;               /* HW address type */
 608        u8 hlen;                /* HW address length */
 609        u8 hops;                /* Used only by gateways */
 610        __be32 xid;             /* Transaction ID */
 611        __be16 secs;            /* Seconds since we started */
 612        __be16 flags;           /* Just what it says */
 613        __be32 client_ip;               /* Client's IP address if known */
 614        __be32 your_ip;         /* Assigned IP address */
 615        __be32 server_ip;               /* (Next, e.g. NFS) Server's IP address */
 616        __be32 relay_ip;                /* IP address of BOOTP relay */
 617        u8 hw_addr[16];         /* Client's HW address */
 618        u8 serv_name[64];       /* Server host name */
 619        u8 boot_file[128];      /* Name of boot file */
 620        u8 exten[312];          /* DHCP options / BOOTP vendor extensions */
 621};
 622
 623/* packet ops */
 624#define BOOTP_REQUEST   1
 625#define BOOTP_REPLY     2
 626
 627/* DHCP message types */
 628#define DHCPDISCOVER    1
 629#define DHCPOFFER       2
 630#define DHCPREQUEST     3
 631#define DHCPDECLINE     4
 632#define DHCPACK         5
 633#define DHCPNAK         6
 634#define DHCPRELEASE     7
 635#define DHCPINFORM      8
 636
 637static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
 638
 639static struct packet_type bootp_packet_type __initdata = {
 640        .type = cpu_to_be16(ETH_P_IP),
 641        .func = ic_bootp_recv,
 642};
 643
 644/*
 645 *  Initialize DHCP/BOOTP extension fields in the request.
 646 */
 647
 648static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
 649
 650#ifdef IPCONFIG_DHCP
 651
 652static void __init
 653ic_dhcp_init_options(u8 *options, struct ic_device *d)
 654{
 655        u8 mt = ((ic_servaddr == NONE)
 656                 ? DHCPDISCOVER : DHCPREQUEST);
 657        u8 *e = options;
 658        int len;
 659
 660        pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
 661
 662        memcpy(e, ic_bootp_cookie, 4);  /* RFC1048 Magic Cookie */
 663        e += 4;
 664
 665        *e++ = 53;              /* DHCP message type */
 666        *e++ = 1;
 667        *e++ = mt;
 668
 669        if (mt == DHCPREQUEST) {
 670                *e++ = 54;      /* Server ID (IP address) */
 671                *e++ = 4;
 672                memcpy(e, &ic_servaddr, 4);
 673                e += 4;
 674
 675                *e++ = 50;      /* Requested IP address */
 676                *e++ = 4;
 677                memcpy(e, &ic_myaddr, 4);
 678                e += 4;
 679        }
 680
 681        /* always? */
 682        {
 683                static const u8 ic_req_params[] = {
 684                        1,      /* Subnet mask */
 685                        3,      /* Default gateway */
 686                        6,      /* DNS server */
 687                        12,     /* Host name */
 688                        15,     /* Domain name */
 689                        17,     /* Boot path */
 690                        26,     /* MTU */
 691                        40,     /* NIS domain name */
 692                        42,     /* NTP servers */
 693                };
 694
 695                *e++ = 55;      /* Parameter request list */
 696                *e++ = sizeof(ic_req_params);
 697                memcpy(e, ic_req_params, sizeof(ic_req_params));
 698                e += sizeof(ic_req_params);
 699
 700                if (ic_host_name_set) {
 701                        *e++ = 12;      /* host-name */
 702                        len = strlen(utsname()->nodename);
 703                        *e++ = len;
 704                        memcpy(e, utsname()->nodename, len);
 705                        e += len;
 706                }
 707                if (*vendor_class_identifier) {
 708                        pr_info("DHCP: sending class identifier \"%s\"\n",
 709                                vendor_class_identifier);
 710                        *e++ = 60;      /* Class-identifier */
 711                        len = strlen(vendor_class_identifier);
 712                        *e++ = len;
 713                        memcpy(e, vendor_class_identifier, len);
 714                        e += len;
 715                }
 716                len = strlen(dhcp_client_identifier + 1);
 717                /* the minimum length of identifier is 2, include 1 byte type,
 718                 * and can not be larger than the length of options
 719                 */
 720                if (len >= 1 && len < 312 - (e - options) - 1) {
 721                        *e++ = 61;
 722                        *e++ = len + 1;
 723                        memcpy(e, dhcp_client_identifier, len + 1);
 724                        e += len + 1;
 725                }
 726        }
 727
 728        *e++ = 255;     /* End of the list */
 729}
 730
 731#endif /* IPCONFIG_DHCP */
 732
 733static void __init ic_bootp_init_ext(u8 *e)
 734{
 735        memcpy(e, ic_bootp_cookie, 4);  /* RFC1048 Magic Cookie */
 736        e += 4;
 737        *e++ = 1;               /* Subnet mask request */
 738        *e++ = 4;
 739        e += 4;
 740        *e++ = 3;               /* Default gateway request */
 741        *e++ = 4;
 742        e += 4;
 743#if CONF_NAMESERVERS_MAX > 0
 744        *e++ = 6;               /* (DNS) name server request */
 745        *e++ = 4 * CONF_NAMESERVERS_MAX;
 746        e += 4 * CONF_NAMESERVERS_MAX;
 747#endif
 748        *e++ = 12;              /* Host name request */
 749        *e++ = 32;
 750        e += 32;
 751        *e++ = 40;              /* NIS Domain name request */
 752        *e++ = 32;
 753        e += 32;
 754        *e++ = 17;              /* Boot path */
 755        *e++ = 40;
 756        e += 40;
 757
 758        *e++ = 57;              /* set extension buffer size for reply */
 759        *e++ = 2;
 760        *e++ = 1;               /* 128+236+8+20+14, see dhcpd sources */
 761        *e++ = 150;
 762
 763        *e++ = 255;             /* End of the list */
 764}
 765
 766
 767/*
 768 *  Initialize the DHCP/BOOTP mechanism.
 769 */
 770static inline void __init ic_bootp_init(void)
 771{
 772        /* Re-initialise all name servers and NTP servers to NONE, in case any
 773         * were set via the "ip=" or "nfsaddrs=" kernel command line parameters:
 774         * any IP addresses specified there will already have been decoded but
 775         * are no longer needed
 776         */
 777        ic_nameservers_predef();
 778        ic_ntp_servers_predef();
 779
 780        dev_add_pack(&bootp_packet_type);
 781}
 782
 783
 784/*
 785 *  DHCP/BOOTP cleanup.
 786 */
 787static inline void __init ic_bootp_cleanup(void)
 788{
 789        dev_remove_pack(&bootp_packet_type);
 790}
 791
 792
 793/*
 794 *  Send DHCP/BOOTP request to single interface.
 795 */
 796static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
 797{
 798        struct net_device *dev = d->dev;
 799        struct sk_buff *skb;
 800        struct bootp_pkt *b;
 801        struct iphdr *h;
 802        int hlen = LL_RESERVED_SPACE(dev);
 803        int tlen = dev->needed_tailroom;
 804
 805        /* Allocate packet */
 806        skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
 807                        GFP_KERNEL);
 808        if (!skb)
 809                return;
 810        skb_reserve(skb, hlen);
 811        b = skb_put_zero(skb, sizeof(struct bootp_pkt));
 812
 813        /* Construct IP header */
 814        skb_reset_network_header(skb);
 815        h = ip_hdr(skb);
 816        h->version = 4;
 817        h->ihl = 5;
 818        h->tot_len = htons(sizeof(struct bootp_pkt));
 819        h->frag_off = htons(IP_DF);
 820        h->ttl = 64;
 821        h->protocol = IPPROTO_UDP;
 822        h->daddr = htonl(INADDR_BROADCAST);
 823        h->check = ip_fast_csum((unsigned char *) h, h->ihl);
 824
 825        /* Construct UDP header */
 826        b->udph.source = htons(68);
 827        b->udph.dest = htons(67);
 828        b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
 829        /* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
 830
 831        /* Construct DHCP/BOOTP header */
 832        b->op = BOOTP_REQUEST;
 833        if (dev->type < 256) /* check for false types */
 834                b->htype = dev->type;
 835        else if (dev->type == ARPHRD_FDDI)
 836                b->htype = ARPHRD_ETHER;
 837        else {
 838                pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
 839                        dev->name);
 840                b->htype = dev->type; /* can cause undefined behavior */
 841        }
 842
 843        /* server_ip and your_ip address are both already zero per RFC2131 */
 844        b->hlen = dev->addr_len;
 845        memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
 846        b->secs = htons(jiffies_diff / HZ);
 847        b->xid = d->xid;
 848
 849        /* add DHCP options or BOOTP extensions */
 850#ifdef IPCONFIG_DHCP
 851        if (ic_proto_enabled & IC_USE_DHCP)
 852                ic_dhcp_init_options(b->exten, d);
 853        else
 854#endif
 855                ic_bootp_init_ext(b->exten);
 856
 857        /* Chain packet down the line... */
 858        skb->dev = dev;
 859        skb->protocol = htons(ETH_P_IP);
 860        if (dev_hard_header(skb, dev, ntohs(skb->protocol),
 861                            dev->broadcast, dev->dev_addr, skb->len) < 0) {
 862                kfree_skb(skb);
 863                printk("E");
 864                return;
 865        }
 866
 867        if (dev_queue_xmit(skb) < 0)
 868                printk("E");
 869}
 870
 871
 872/*
 873 *  Copy BOOTP-supplied string if not already set.
 874 */
 875static int __init ic_bootp_string(char *dest, char *src, int len, int max)
 876{
 877        if (!len)
 878                return 0;
 879        if (len > max-1)
 880                len = max-1;
 881        memcpy(dest, src, len);
 882        dest[len] = '\0';
 883        return 1;
 884}
 885
 886
 887/*
 888 *  Process BOOTP extensions.
 889 */
 890static void __init ic_do_bootp_ext(u8 *ext)
 891{
 892        u8 servers;
 893        int i;
 894        __be16 mtu;
 895
 896        u8 *c;
 897
 898        pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
 899        for (c=ext+2; c<ext+2+ext[1]; c++)
 900                pr_debug(" %02x", *c);
 901        pr_debug("\n");
 902
 903        switch (*ext++) {
 904        case 1:         /* Subnet mask */
 905                if (ic_netmask == NONE)
 906                        memcpy(&ic_netmask, ext+1, 4);
 907                break;
 908        case 3:         /* Default gateway */
 909                if (ic_gateway == NONE)
 910                        memcpy(&ic_gateway, ext+1, 4);
 911                break;
 912        case 6:         /* DNS server */
 913                servers= *ext/4;
 914                if (servers > CONF_NAMESERVERS_MAX)
 915                        servers = CONF_NAMESERVERS_MAX;
 916                for (i = 0; i < servers; i++) {
 917                        if (ic_nameservers[i] == NONE)
 918                                memcpy(&ic_nameservers[i], ext+1+4*i, 4);
 919                }
 920                break;
 921        case 12:        /* Host name */
 922                ic_bootp_string(utsname()->nodename, ext+1, *ext,
 923                                __NEW_UTS_LEN);
 924                ic_host_name_set = 1;
 925                break;
 926        case 15:        /* Domain name (DNS) */
 927                ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
 928                break;
 929        case 17:        /* Root path */
 930                if (!root_server_path[0])
 931                        ic_bootp_string(root_server_path, ext+1, *ext,
 932                                        sizeof(root_server_path));
 933                break;
 934        case 26:        /* Interface MTU */
 935                memcpy(&mtu, ext+1, sizeof(mtu));
 936                ic_dev_mtu = ntohs(mtu);
 937                break;
 938        case 40:        /* NIS Domain name (_not_ DNS) */
 939                ic_bootp_string(utsname()->domainname, ext+1, *ext,
 940                                __NEW_UTS_LEN);
 941                break;
 942        case 42:        /* NTP servers */
 943                servers = *ext / 4;
 944                if (servers > CONF_NTP_SERVERS_MAX)
 945                        servers = CONF_NTP_SERVERS_MAX;
 946                for (i = 0; i < servers; i++) {
 947                        if (ic_ntp_servers[i] == NONE)
 948                                memcpy(&ic_ntp_servers[i], ext+1+4*i, 4);
 949                }
 950                break;
 951        }
 952}
 953
 954
 955/*
 956 *  Receive BOOTP reply.
 957 */
 958static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 959{
 960        struct bootp_pkt *b;
 961        struct iphdr *h;
 962        struct ic_device *d;
 963        int len, ext_len;
 964
 965        if (!net_eq(dev_net(dev), &init_net))
 966                goto drop;
 967
 968        /* Perform verifications before taking the lock.  */
 969        if (skb->pkt_type == PACKET_OTHERHOST)
 970                goto drop;
 971
 972        skb = skb_share_check(skb, GFP_ATOMIC);
 973        if (!skb)
 974                return NET_RX_DROP;
 975
 976        if (!pskb_may_pull(skb,
 977                           sizeof(struct iphdr) +
 978                           sizeof(struct udphdr)))
 979                goto drop;
 980
 981        b = (struct bootp_pkt *)skb_network_header(skb);
 982        h = &b->iph;
 983
 984        if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
 985                goto drop;
 986
 987        /* Fragments are not supported */
 988        if (ip_is_fragment(h)) {
 989                net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
 990                goto drop;
 991        }
 992
 993        if (skb->len < ntohs(h->tot_len))
 994                goto drop;
 995
 996        if (ip_fast_csum((char *) h, h->ihl))
 997                goto drop;
 998
 999        if (b->udph.source != htons(67) || b->udph.dest != htons(68))
1000                goto drop;
1001
1002        if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
1003                goto drop;
1004
1005        len = ntohs(b->udph.len) - sizeof(struct udphdr);
1006        ext_len = len - (sizeof(*b) -
1007                         sizeof(struct iphdr) -
1008                         sizeof(struct udphdr) -
1009                         sizeof(b->exten));
1010        if (ext_len < 0)
1011                goto drop;
1012
1013        /* Ok the front looks good, make sure we can get at the rest.  */
1014        if (!pskb_may_pull(skb, skb->len))
1015                goto drop;
1016
1017        b = (struct bootp_pkt *)skb_network_header(skb);
1018        h = &b->iph;
1019
1020        /* One reply at a time, please. */
1021        spin_lock(&ic_recv_lock);
1022
1023        /* If we already have a reply, just drop the packet */
1024        if (ic_got_reply)
1025                goto drop_unlock;
1026
1027        /* Find the ic_device that the packet arrived on */
1028        d = ic_first_dev;
1029        while (d && d->dev != dev)
1030                d = d->next;
1031        if (!d)
1032                goto drop_unlock;  /* should never happen */
1033
1034        /* Is it a reply to our BOOTP request? */
1035        if (b->op != BOOTP_REPLY ||
1036            b->xid != d->xid) {
1037                net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1038                                    d->dev->name, b->op, b->xid);
1039                goto drop_unlock;
1040        }
1041
1042        /* Parse extensions */
1043        if (ext_len >= 4 &&
1044            !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1045                u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1046                u8 *ext;
1047
1048#ifdef IPCONFIG_DHCP
1049                if (ic_proto_enabled & IC_USE_DHCP) {
1050                        __be32 server_id = NONE;
1051                        int mt = 0;
1052
1053                        ext = &b->exten[4];
1054                        while (ext < end && *ext != 0xff) {
1055                                u8 *opt = ext++;
1056                                if (*opt == 0)  /* Padding */
1057                                        continue;
1058                                ext += *ext + 1;
1059                                if (ext >= end)
1060                                        break;
1061                                switch (*opt) {
1062                                case 53:        /* Message type */
1063                                        if (opt[1])
1064                                                mt = opt[2];
1065                                        break;
1066                                case 54:        /* Server ID (IP address) */
1067                                        if (opt[1] >= 4)
1068                                                memcpy(&server_id, opt + 2, 4);
1069                                        break;
1070                                }
1071                        }
1072
1073                        pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1074
1075                        switch (mt) {
1076                        case DHCPOFFER:
1077                                /* While in the process of accepting one offer,
1078                                 * ignore all others.
1079                                 */
1080                                if (ic_myaddr != NONE)
1081                                        goto drop_unlock;
1082
1083                                /* Let's accept that offer. */
1084                                ic_myaddr = b->your_ip;
1085                                ic_servaddr = server_id;
1086                                pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1087                                         &ic_myaddr, &b->iph.saddr);
1088                                /* The DHCP indicated server address takes
1089                                 * precedence over the bootp header one if
1090                                 * they are different.
1091                                 */
1092                                if ((server_id != NONE) &&
1093                                    (b->server_ip != server_id))
1094                                        b->server_ip = ic_servaddr;
1095                                break;
1096
1097                        case DHCPACK:
1098                                if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1099                                        goto drop_unlock;
1100
1101                                /* Yeah! */
1102                                break;
1103
1104                        default:
1105                                /* Urque.  Forget it*/
1106                                ic_myaddr = NONE;
1107                                ic_servaddr = NONE;
1108                                goto drop_unlock;
1109                        }
1110
1111                        ic_dhcp_msgtype = mt;
1112
1113                }
1114#endif /* IPCONFIG_DHCP */
1115
1116                ext = &b->exten[4];
1117                while (ext < end && *ext != 0xff) {
1118                        u8 *opt = ext++;
1119                        if (*opt == 0)  /* Padding */
1120                                continue;
1121                        ext += *ext + 1;
1122                        if (ext < end)
1123                                ic_do_bootp_ext(opt);
1124                }
1125        }
1126
1127        /* We have a winner! */
1128        ic_dev = d;
1129        ic_myaddr = b->your_ip;
1130        ic_servaddr = b->server_ip;
1131        ic_addrservaddr = b->iph.saddr;
1132        if (ic_gateway == NONE && b->relay_ip)
1133                ic_gateway = b->relay_ip;
1134        if (ic_nameservers[0] == NONE)
1135                ic_nameservers[0] = ic_servaddr;
1136        ic_got_reply = IC_BOOTP;
1137
1138drop_unlock:
1139        /* Show's over.  Nothing to see here.  */
1140        spin_unlock(&ic_recv_lock);
1141
1142drop:
1143        /* Throw the packet out. */
1144        kfree_skb(skb);
1145
1146        return 0;
1147}
1148
1149
1150#endif
1151
1152
1153/*
1154 *      Dynamic IP configuration -- DHCP, BOOTP, RARP.
1155 */
1156
1157#ifdef IPCONFIG_DYNAMIC
1158
1159static int __init ic_dynamic(void)
1160{
1161        int retries;
1162        struct ic_device *d;
1163        unsigned long start_jiffies, timeout, jiff;
1164        int do_bootp = ic_proto_have_if & IC_BOOTP;
1165        int do_rarp = ic_proto_have_if & IC_RARP;
1166
1167        /*
1168         * If none of DHCP/BOOTP/RARP was selected, return with an error.
1169         * This routine gets only called when some pieces of information
1170         * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1171         */
1172        if (!ic_proto_enabled) {
1173                pr_err("IP-Config: Incomplete network configuration information\n");
1174                return -1;
1175        }
1176
1177#ifdef IPCONFIG_BOOTP
1178        if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1179                pr_err("DHCP/BOOTP: No suitable device found\n");
1180#endif
1181#ifdef IPCONFIG_RARP
1182        if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1183                pr_err("RARP: No suitable device found\n");
1184#endif
1185
1186        if (!ic_proto_have_if)
1187                /* Error message already printed */
1188                return -1;
1189
1190        /*
1191         * Setup protocols
1192         */
1193#ifdef IPCONFIG_BOOTP
1194        if (do_bootp)
1195                ic_bootp_init();
1196#endif
1197#ifdef IPCONFIG_RARP
1198        if (do_rarp)
1199                ic_rarp_init();
1200#endif
1201
1202        /*
1203         * Send requests and wait, until we get an answer. This loop
1204         * seems to be a terrible waste of CPU time, but actually there is
1205         * only one process running at all, so we don't need to use any
1206         * scheduler functions.
1207         * [Actually we could now, but the nothing else running note still
1208         *  applies.. - AC]
1209         */
1210        pr_notice("Sending %s%s%s requests .",
1211                  do_bootp
1212                  ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1213                  (do_bootp && do_rarp) ? " and " : "",
1214                  do_rarp ? "RARP" : "");
1215
1216        start_jiffies = jiffies;
1217        d = ic_first_dev;
1218        retries = CONF_SEND_RETRIES;
1219        get_random_bytes(&timeout, sizeof(timeout));
1220        timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1221        for (;;) {
1222#ifdef IPCONFIG_BOOTP
1223                if (do_bootp && (d->able & IC_BOOTP))
1224                        ic_bootp_send_if(d, jiffies - start_jiffies);
1225#endif
1226#ifdef IPCONFIG_RARP
1227                if (do_rarp && (d->able & IC_RARP))
1228                        ic_rarp_send_if(d);
1229#endif
1230
1231                if (!d->next) {
1232                        jiff = jiffies + timeout;
1233                        while (time_before(jiffies, jiff) && !ic_got_reply)
1234                                schedule_timeout_uninterruptible(1);
1235                }
1236#ifdef IPCONFIG_DHCP
1237                /* DHCP isn't done until we get a DHCPACK. */
1238                if ((ic_got_reply & IC_BOOTP) &&
1239                    (ic_proto_enabled & IC_USE_DHCP) &&
1240                    ic_dhcp_msgtype != DHCPACK) {
1241                        ic_got_reply = 0;
1242                        /* continue on device that got the reply */
1243                        d = ic_dev;
1244                        pr_cont(",");
1245                        continue;
1246                }
1247#endif /* IPCONFIG_DHCP */
1248
1249                if (ic_got_reply) {
1250                        pr_cont(" OK\n");
1251                        break;
1252                }
1253
1254                if ((d = d->next))
1255                        continue;
1256
1257                if (! --retries) {
1258                        pr_cont(" timed out!\n");
1259                        break;
1260                }
1261
1262                d = ic_first_dev;
1263
1264                timeout = timeout CONF_TIMEOUT_MULT;
1265                if (timeout > CONF_TIMEOUT_MAX)
1266                        timeout = CONF_TIMEOUT_MAX;
1267
1268                pr_cont(".");
1269        }
1270
1271#ifdef IPCONFIG_BOOTP
1272        if (do_bootp)
1273                ic_bootp_cleanup();
1274#endif
1275#ifdef IPCONFIG_RARP
1276        if (do_rarp)
1277                ic_rarp_cleanup();
1278#endif
1279
1280        if (!ic_got_reply) {
1281                ic_myaddr = NONE;
1282                return -1;
1283        }
1284
1285        pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1286                ((ic_got_reply & IC_RARP) ? "RARP"
1287                : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1288                &ic_addrservaddr, &ic_myaddr);
1289
1290        return 0;
1291}
1292
1293#endif /* IPCONFIG_DYNAMIC */
1294
1295#ifdef CONFIG_PROC_FS
1296/* proc_dir_entry for /proc/net/ipconfig */
1297static struct proc_dir_entry *ipconfig_dir;
1298
1299/* Name servers: */
1300static int pnp_seq_show(struct seq_file *seq, void *v)
1301{
1302        int i;
1303
1304        if (ic_proto_used & IC_PROTO)
1305                seq_printf(seq, "#PROTO: %s\n",
1306                           (ic_proto_used & IC_RARP) ? "RARP"
1307                           : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1308        else
1309                seq_puts(seq, "#MANUAL\n");
1310
1311        if (ic_domain[0])
1312                seq_printf(seq,
1313                           "domain %s\n", ic_domain);
1314        for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1315                if (ic_nameservers[i] != NONE)
1316                        seq_printf(seq, "nameserver %pI4\n",
1317                                   &ic_nameservers[i]);
1318        }
1319        if (ic_servaddr != NONE)
1320                seq_printf(seq, "bootserver %pI4\n",
1321                           &ic_servaddr);
1322        return 0;
1323}
1324
1325/* Create the /proc/net/ipconfig directory */
1326static int __init ipconfig_proc_net_init(void)
1327{
1328        ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net);
1329        if (!ipconfig_dir)
1330                return -ENOMEM;
1331
1332        return 0;
1333}
1334
1335/* Create a new file under /proc/net/ipconfig */
1336static int ipconfig_proc_net_create(const char *name,
1337                                    const struct proc_ops *proc_ops)
1338{
1339        char *pname;
1340        struct proc_dir_entry *p;
1341
1342        if (!ipconfig_dir)
1343                return -ENOMEM;
1344
1345        pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name);
1346        if (!pname)
1347                return -ENOMEM;
1348
1349        p = proc_create(pname, 0444, init_net.proc_net, proc_ops);
1350        kfree(pname);
1351        if (!p)
1352                return -ENOMEM;
1353
1354        return 0;
1355}
1356
1357/* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */
1358static int ntp_servers_show(struct seq_file *seq, void *v)
1359{
1360        int i;
1361
1362        for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1363                if (ic_ntp_servers[i] != NONE)
1364                        seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]);
1365        }
1366        return 0;
1367}
1368DEFINE_PROC_SHOW_ATTRIBUTE(ntp_servers);
1369#endif /* CONFIG_PROC_FS */
1370
1371/*
1372 *  Extract IP address from the parameter string if needed. Note that we
1373 *  need to have root_server_addr set _before_ IPConfig gets called as it
1374 *  can override it.
1375 */
1376__be32 __init root_nfs_parse_addr(char *name)
1377{
1378        __be32 addr;
1379        int octets = 0;
1380        char *cp, *cq;
1381
1382        cp = cq = name;
1383        while (octets < 4) {
1384                while (*cp >= '0' && *cp <= '9')
1385                        cp++;
1386                if (cp == cq || cp - cq > 3)
1387                        break;
1388                if (*cp == '.' || octets == 3)
1389                        octets++;
1390                if (octets < 4)
1391                        cp++;
1392                cq = cp;
1393        }
1394        if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1395                if (*cp == ':')
1396                        *cp++ = '\0';
1397                addr = in_aton(name);
1398                memmove(name, cp, strlen(cp) + 1);
1399        } else
1400                addr = NONE;
1401
1402        return addr;
1403}
1404
1405#define DEVICE_WAIT_MAX         12 /* 12 seconds */
1406
1407static int __init wait_for_devices(void)
1408{
1409        int i;
1410
1411        for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1412                struct net_device *dev;
1413                int found = 0;
1414
1415                /* make sure deferred device probes are finished */
1416                wait_for_device_probe();
1417
1418                rtnl_lock();
1419                for_each_netdev(&init_net, dev) {
1420                        if (ic_is_init_dev(dev)) {
1421                                found = 1;
1422                                break;
1423                        }
1424                }
1425                rtnl_unlock();
1426                if (found)
1427                        return 0;
1428                ssleep(1);
1429        }
1430        return -ENODEV;
1431}
1432
1433/*
1434 *      IP Autoconfig dispatcher.
1435 */
1436
1437static int __init ip_auto_config(void)
1438{
1439        __be32 addr;
1440#ifdef IPCONFIG_DYNAMIC
1441        int retries = CONF_OPEN_RETRIES;
1442#endif
1443        int err;
1444        unsigned int i;
1445
1446        /* Initialise all name servers and NTP servers to NONE (but only if the
1447         * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded,
1448         * otherwise we'll overwrite the IP addresses specified there)
1449         */
1450        if (ic_set_manually == 0) {
1451                ic_nameservers_predef();
1452                ic_ntp_servers_predef();
1453        }
1454
1455#ifdef CONFIG_PROC_FS
1456        proc_create_single("pnp", 0444, init_net.proc_net, pnp_seq_show);
1457
1458        if (ipconfig_proc_net_init() == 0)
1459                ipconfig_proc_net_create("ntp_servers", &ntp_servers_proc_ops);
1460#endif /* CONFIG_PROC_FS */
1461
1462        if (!ic_enable)
1463                return 0;
1464
1465        pr_debug("IP-Config: Entered.\n");
1466#ifdef IPCONFIG_DYNAMIC
1467 try_try_again:
1468#endif
1469        /* Wait for devices to appear */
1470        err = wait_for_devices();
1471        if (err)
1472                return err;
1473
1474        /* Setup all network devices */
1475        err = ic_open_devs();
1476        if (err)
1477                return err;
1478
1479        /* Give drivers a chance to settle */
1480        msleep(CONF_POST_OPEN);
1481
1482        /*
1483         * If the config information is insufficient (e.g., our IP address or
1484         * IP address of the boot server is missing or we have multiple network
1485         * interfaces and no default was set), use BOOTP or RARP to get the
1486         * missing values.
1487         */
1488        if (ic_myaddr == NONE ||
1489#if defined(CONFIG_ROOT_NFS) || defined(CONFIG_CIFS_ROOT)
1490            (root_server_addr == NONE &&
1491             ic_servaddr == NONE &&
1492             (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) ||
1493#endif
1494            ic_first_dev->next) {
1495#ifdef IPCONFIG_DYNAMIC
1496                if (ic_dynamic() < 0) {
1497                        ic_close_devs();
1498
1499                        /*
1500                         * I don't know why, but sometimes the
1501                         * eepro100 driver (at least) gets upset and
1502                         * doesn't work the first time it's opened.
1503                         * But then if you close it and reopen it, it
1504                         * works just fine.  So we need to try that at
1505                         * least once before giving up.
1506                         *
1507                         * Also, if the root will be NFS-mounted, we
1508                         * have nowhere to go if DHCP fails.  So we
1509                         * just have to keep trying forever.
1510                         *
1511                         *                              -- Chip
1512                         */
1513#ifdef CONFIG_ROOT_NFS
1514                        if (ROOT_DEV ==  Root_NFS) {
1515                                pr_err("IP-Config: Retrying forever (NFS root)...\n");
1516                                goto try_try_again;
1517                        }
1518#endif
1519#ifdef CONFIG_CIFS_ROOT
1520                        if (ROOT_DEV == Root_CIFS) {
1521                                pr_err("IP-Config: Retrying forever (CIFS root)...\n");
1522                                goto try_try_again;
1523                        }
1524#endif
1525
1526                        if (--retries) {
1527                                pr_err("IP-Config: Reopening network devices...\n");
1528                                goto try_try_again;
1529                        }
1530
1531                        /* Oh, well.  At least we tried. */
1532                        pr_err("IP-Config: Auto-configuration of network failed\n");
1533                        return -1;
1534                }
1535#else /* !DYNAMIC */
1536                pr_err("IP-Config: Incomplete network configuration information\n");
1537                ic_close_devs();
1538                return -1;
1539#endif /* IPCONFIG_DYNAMIC */
1540        } else {
1541                /* Device selected manually or only one device -> use it */
1542                ic_dev = ic_first_dev;
1543        }
1544
1545        addr = root_nfs_parse_addr(root_server_path);
1546        if (root_server_addr == NONE)
1547                root_server_addr = addr;
1548
1549        /*
1550         * Use defaults wherever applicable.
1551         */
1552        if (ic_defaults() < 0)
1553                return -1;
1554
1555        /*
1556         * Record which protocol was actually used.
1557         */
1558#ifdef IPCONFIG_DYNAMIC
1559        ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1560#endif
1561
1562#ifndef IPCONFIG_SILENT
1563        /*
1564         * Clue in the operator.
1565         */
1566        pr_info("IP-Config: Complete:\n");
1567
1568        pr_info("     device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1569                ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1570                &ic_myaddr, &ic_netmask, &ic_gateway);
1571        pr_info("     host=%s, domain=%s, nis-domain=%s\n",
1572                utsname()->nodename, ic_domain, utsname()->domainname);
1573        pr_info("     bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1574                &ic_servaddr, &root_server_addr, root_server_path);
1575        if (ic_dev_mtu)
1576                pr_cont(", mtu=%d", ic_dev_mtu);
1577        /* Name servers (if any): */
1578        for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1579                if (ic_nameservers[i] != NONE) {
1580                        if (i == 0)
1581                                pr_info("     nameserver%u=%pI4",
1582                                        i, &ic_nameservers[i]);
1583                        else
1584                                pr_cont(", nameserver%u=%pI4",
1585                                        i, &ic_nameservers[i]);
1586                }
1587                if (i + 1 == CONF_NAMESERVERS_MAX)
1588                        pr_cont("\n");
1589        }
1590        /* NTP servers (if any): */
1591        for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1592                if (ic_ntp_servers[i] != NONE) {
1593                        if (i == 0)
1594                                pr_info("     ntpserver%u=%pI4",
1595                                        i, &ic_ntp_servers[i]);
1596                        else
1597                                pr_cont(", ntpserver%u=%pI4",
1598                                        i, &ic_ntp_servers[i]);
1599                }
1600                if (i + 1 == CONF_NTP_SERVERS_MAX)
1601                        pr_cont("\n");
1602        }
1603#endif /* !SILENT */
1604
1605        /*
1606         * Close all network devices except the device we've
1607         * autoconfigured and set up routes.
1608         */
1609        if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1610                err = -1;
1611        else
1612                err = 0;
1613
1614        ic_close_devs();
1615
1616        return err;
1617}
1618
1619late_initcall(ip_auto_config);
1620
1621
1622/*
1623 *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1624 *  command line parameter.  See Documentation/filesystems/nfs/nfsroot.txt.
1625 */
1626static int __init ic_proto_name(char *name)
1627{
1628        if (!strcmp(name, "on") || !strcmp(name, "any")) {
1629                return 1;
1630        }
1631        if (!strcmp(name, "off") || !strcmp(name, "none")) {
1632                return 0;
1633        }
1634#ifdef CONFIG_IP_PNP_DHCP
1635        else if (!strncmp(name, "dhcp", 4)) {
1636                char *client_id;
1637
1638                ic_proto_enabled &= ~IC_RARP;
1639                client_id = strstr(name, "dhcp,");
1640                if (client_id) {
1641                        char *v;
1642
1643                        client_id = client_id + 5;
1644                        v = strchr(client_id, ',');
1645                        if (!v)
1646                                return 1;
1647                        *v = 0;
1648                        if (kstrtou8(client_id, 0, dhcp_client_identifier))
1649                                pr_debug("DHCP: Invalid client identifier type\n");
1650                        strncpy(dhcp_client_identifier + 1, v + 1, 251);
1651                        *v = ',';
1652                }
1653                return 1;
1654        }
1655#endif
1656#ifdef CONFIG_IP_PNP_BOOTP
1657        else if (!strcmp(name, "bootp")) {
1658                ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1659                return 1;
1660        }
1661#endif
1662#ifdef CONFIG_IP_PNP_RARP
1663        else if (!strcmp(name, "rarp")) {
1664                ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1665                return 1;
1666        }
1667#endif
1668#ifdef IPCONFIG_DYNAMIC
1669        else if (!strcmp(name, "both")) {
1670                ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1671                return 1;
1672        }
1673#endif
1674        return 0;
1675}
1676
1677static int __init ip_auto_config_setup(char *addrs)
1678{
1679        char *cp, *ip, *dp;
1680        int num = 0;
1681
1682        ic_set_manually = 1;
1683        ic_enable = 1;
1684
1685        /*
1686         * If any dhcp, bootp etc options are set, leave autoconfig on
1687         * and skip the below static IP processing.
1688         */
1689        if (ic_proto_name(addrs))
1690                return 1;
1691
1692        /* If no static IP is given, turn off autoconfig and bail.  */
1693        if (*addrs == 0 ||
1694            strcmp(addrs, "off") == 0 ||
1695            strcmp(addrs, "none") == 0) {
1696                ic_enable = 0;
1697                return 1;
1698        }
1699
1700        /* Initialise all name servers and NTP servers to NONE */
1701        ic_nameservers_predef();
1702        ic_ntp_servers_predef();
1703
1704        /* Parse string for static IP assignment.  */
1705        ip = addrs;
1706        while (ip && *ip) {
1707                if ((cp = strchr(ip, ':')))
1708                        *cp++ = '\0';
1709                if (strlen(ip) > 0) {
1710                        pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1711                        switch (num) {
1712                        case 0:
1713                                if ((ic_myaddr = in_aton(ip)) == ANY)
1714                                        ic_myaddr = NONE;
1715                                break;
1716                        case 1:
1717                                if ((ic_servaddr = in_aton(ip)) == ANY)
1718                                        ic_servaddr = NONE;
1719                                break;
1720                        case 2:
1721                                if ((ic_gateway = in_aton(ip)) == ANY)
1722                                        ic_gateway = NONE;
1723                                break;
1724                        case 3:
1725                                if ((ic_netmask = in_aton(ip)) == ANY)
1726                                        ic_netmask = NONE;
1727                                break;
1728                        case 4:
1729                                if ((dp = strchr(ip, '.'))) {
1730                                        *dp++ = '\0';
1731                                        strlcpy(utsname()->domainname, dp,
1732                                                sizeof(utsname()->domainname));
1733                                }
1734                                strlcpy(utsname()->nodename, ip,
1735                                        sizeof(utsname()->nodename));
1736                                ic_host_name_set = 1;
1737                                break;
1738                        case 5:
1739                                strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1740                                break;
1741                        case 6:
1742                                if (ic_proto_name(ip) == 0 &&
1743                                    ic_myaddr == NONE) {
1744                                        ic_enable = 0;
1745                                }
1746                                break;
1747                        case 7:
1748                                if (CONF_NAMESERVERS_MAX >= 1) {
1749                                        ic_nameservers[0] = in_aton(ip);
1750                                        if (ic_nameservers[0] == ANY)
1751                                                ic_nameservers[0] = NONE;
1752                                }
1753                                break;
1754                        case 8:
1755                                if (CONF_NAMESERVERS_MAX >= 2) {
1756                                        ic_nameservers[1] = in_aton(ip);
1757                                        if (ic_nameservers[1] == ANY)
1758                                                ic_nameservers[1] = NONE;
1759                                }
1760                                break;
1761                        case 9:
1762                                if (CONF_NTP_SERVERS_MAX >= 1) {
1763                                        ic_ntp_servers[0] = in_aton(ip);
1764                                        if (ic_ntp_servers[0] == ANY)
1765                                                ic_ntp_servers[0] = NONE;
1766                                }
1767                                break;
1768                        }
1769                }
1770                ip = cp;
1771                num++;
1772        }
1773
1774        return 1;
1775}
1776__setup("ip=", ip_auto_config_setup);
1777
1778static int __init nfsaddrs_config_setup(char *addrs)
1779{
1780        return ip_auto_config_setup(addrs);
1781}
1782__setup("nfsaddrs=", nfsaddrs_config_setup);
1783
1784static int __init vendor_class_identifier_setup(char *addrs)
1785{
1786        if (strlcpy(vendor_class_identifier, addrs,
1787                    sizeof(vendor_class_identifier))
1788            >= sizeof(vendor_class_identifier))
1789                pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1790                        vendor_class_identifier);
1791        return 1;
1792}
1793__setup("dhcpclass=", vendor_class_identifier_setup);
1794
1795static int __init set_carrier_timeout(char *str)
1796{
1797        ssize_t ret;
1798
1799        if (!str)
1800                return 0;
1801
1802        ret = kstrtouint(str, 0, &carrier_timeout);
1803        if (ret)
1804                return 0;
1805
1806        return 1;
1807}
1808__setup("carrier_timeout=", set_carrier_timeout);
1809