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/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 #define CONF_CARRIER_TIMEOUT    120000  /* Wait for carrier timeout */
  89
  90 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
  91 #define CONF_OPEN_RETRIES       2       /* (Re)open devices twice */
  92 #define CONF_SEND_RETRIES       6       /* Send six requests per open */
  93 #define CONF_BASE_TIMEOUT       (HZ*2)  /* Initial timeout: 2 seconds */
  94 #define CONF_TIMEOUT_RANDOM     (HZ)    /* Maximum amount of randomization */
  95 #define CONF_TIMEOUT_MULT       *7/4    /* Rate of timeout growth */
  96 #define CONF_TIMEOUT_MAX        (HZ*30) /* Maximum allowed timeout */
  97 #define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
  98                                            - '3' from resolv.h */
  99 #define CONF_NTP_SERVERS_MAX   3        /* Maximum number of NTP servers */
 100
 101 #define NONE cpu_to_be32(INADDR_NONE)
 102 #define ANY cpu_to_be32(INADDR_ANY)
 103
 104 /*
 105  * Public IP configuration
 106  */
 107
 108 /* This is used by platforms which might be able to set the ipconfig
 109  * variables using firmware environment vars.  If this is set, it will
 110  * ignore such firmware variables.
 111  */
 112 int ic_set_manually __initdata = 0;             /* IPconfig parameters set manually */
 113
 114 static int ic_enable __initdata;                /* IP config enabled? */
 115
 116 /* Protocol choice */
 117 int ic_proto_enabled __initdata = 0
 118 #ifdef IPCONFIG_BOOTP
 119                         | IC_BOOTP
 120 #endif
 121 #ifdef CONFIG_IP_PNP_DHCP
 122                         | IC_USE_DHCP
 123 #endif
 124 #ifdef IPCONFIG_RARP
 125                         | IC_RARP
 126 #endif
 127                         ;
 128
 129 static int ic_host_name_set __initdata; /* Host name set by us? */
 130
 131 __be32 ic_myaddr = NONE;                /* My IP address */
 132 static __be32 ic_netmask = NONE;        /* Netmask for local subnet */
 133 __be32 ic_gateway = NONE;       /* Gateway IP address */
 134
 135 #ifdef IPCONFIG_DYNAMIC
 136 static __be32 ic_addrservaddr = NONE;   /* IP Address of the IP addresses'server */
 137 #endif
 138
 139 __be32 ic_servaddr = NONE;      /* Boot server IP address */
 140
 141 __be32 root_server_addr = NONE; /* Address of NFS server */
 142 u8 root_server_path[256] = { 0, };      /* Path to mount as root */
 143
 144 /* vendor class identifier */
 145 static char vendor_class_identifier[253] __initdata;
 146
 147 #if defined(CONFIG_IP_PNP_DHCP)
 148 static char dhcp_client_identifier[253] __initdata;
 149 #endif
 150
 151 /* Persistent data: */
 152
 153 #ifdef IPCONFIG_DYNAMIC
 154 static int ic_proto_used;                       /* Protocol used, if any */
 155 #else
 156 #define ic_proto_used 0
 157 #endif
 158 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
 159 static __be32 ic_ntp_servers[CONF_NTP_SERVERS_MAX]; /* NTP server IP addresses */
 160 static u8 ic_domain[64];                /* DNS (not NIS) domain name */
 161
 162 /*
 163  * Private state.
 164  */
 165
 166 /* Name of user-selected boot device */
 167 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
 168
 169 /* Protocols supported by available interfaces */
 170 static int ic_proto_have_if __initdata;
 171
 172 /* MTU for boot device */
 173 static int ic_dev_mtu __initdata;
 174
 175 #ifdef IPCONFIG_DYNAMIC
 176 static DEFINE_SPINLOCK(ic_recv_lock);
 177 static volatile int ic_got_reply __initdata;    /* Proto(s) that replied */
 178 #endif
 179 #ifdef IPCONFIG_DHCP
 180 static int ic_dhcp_msgtype __initdata;  /* DHCP msg type received */
 181 #endif
 182
 183
 184 /*
 185  *      Network devices
 186  */
 187
 188 struct ic_device {
 189         struct ic_device *next;
 190         struct net_device *dev;
 191         unsigned short flags;
 192         short able;
 193         __be32 xid;
 194 };
 195
 196 static struct ic_device *ic_first_dev __initdata;       /* List of open device */
 197 static struct ic_device *ic_dev __initdata;             /* Selected device */
 198
 199 static bool __init ic_is_init_dev(struct net_device *dev)
 200 {
 201         if (dev->flags & IFF_LOOPBACK)
 202                 return false;
 203         return user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
 204             (!(dev->flags & IFF_LOOPBACK) &&
 205              (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
 206              strncmp(dev->name, "dummy", 5));
 207 }
 208
 209 static int __init ic_open_devs(void)
 210 {
 211         struct ic_device *d, **last;
 212         struct net_device *dev;
 213         unsigned short oflags;
 214         unsigned long start, next_msg;
 215
 216         last = &ic_first_dev;
 217         rtnl_lock();
 218
 219         /* bring loopback and DSA master network devices up first */
 220         for_each_netdev(&init_net, dev) {
 221                 if (!(dev->flags & IFF_LOOPBACK) && !netdev_uses_dsa(dev))
 222                         continue;
 223                 if (dev_change_flags(dev, dev->flags | IFF_UP, NULL) < 0)
 224                         pr_err("IP-Config: Failed to open %s\n", dev->name);
 225         }
 226
 227         for_each_netdev(&init_net, dev) {
 228                 if (ic_is_init_dev(dev)) {
 229                         int able = 0;
 230                         if (dev->mtu >= 364)
 231                                 able |= IC_BOOTP;
 232                         else
 233                                 pr_warn("DHCP/BOOTP: Ignoring device %s, MTU %d too small\n",
 234                                         dev->name, dev->mtu);
 235                         if (!(dev->flags & IFF_NOARP))
 236                                 able |= IC_RARP;
 237                         able &= ic_proto_enabled;
 238                         if (ic_proto_enabled && !able)
 239                                 continue;
 240                         oflags = dev->flags;
 241                         if (dev_change_flags(dev, oflags | IFF_UP, NULL) < 0) {
 242                                 pr_err("IP-Config: Failed to open %s\n",
 243                                        dev->name);
 244                                 continue;
 245                         }
 246                         if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
 247                                 rtnl_unlock();
 248                                 return -ENOMEM;
 249                         }
 250                         d->dev = dev;
 251                         *last = d;
 252                         last = &d->next;
 253                         d->flags = oflags;
 254                         d->able = able;
 255                         if (able & IC_BOOTP)
 256                                 get_random_bytes(&d->xid, sizeof(__be32));
 257                         else
 258                                 d->xid = 0;
 259                         ic_proto_have_if |= able;
 260                         pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n",
 261                                  dev->name, able, d->xid);
 262                 }
 263         }
 264
 265         /* no point in waiting if we could not bring up at least one device */
 266         if (!ic_first_dev)
 267                 goto have_carrier;
 268
 269         /* wait for a carrier on at least one device */
 270         start = jiffies;
 271         next_msg = start + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
 272         while (time_before(jiffies, start +
 273                            msecs_to_jiffies(CONF_CARRIER_TIMEOUT))) {
 274                 int wait, elapsed;
 275
 276                 for_each_netdev(&init_net, dev)
 277                         if (ic_is_init_dev(dev) && netif_carrier_ok(dev))
 278                                 goto have_carrier;
 279
 280                 msleep(1);
 281
 282                 if (time_before(jiffies, next_msg))
 283                         continue;
 284
 285                 elapsed = jiffies_to_msecs(jiffies - start);
 286                 wait = (CONF_CARRIER_TIMEOUT - elapsed + 500)/1000;
 287                 pr_info("Waiting up to %d more seconds for network.\n", wait);
 288                 next_msg = jiffies + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
 289         }
 290 have_carrier:
 291         rtnl_unlock();
 292
 293         *last = NULL;
 294
 295         if (!ic_first_dev) {
 296                 if (user_dev_name[0])
 297                         pr_err("IP-Config: Device `%s' not found\n",
 298                                user_dev_name);
 299                 else
 300                         pr_err("IP-Config: No network devices available\n");
 301                 return -ENODEV;
 302         }
 303         return 0;
 304 }
 305
 306 static void __init ic_close_devs(void)
 307 {
 308         struct ic_device *d, *next;
 309         struct net_device *dev;
 310
 311         rtnl_lock();
 312         next = ic_first_dev;
 313         while ((d = next)) {
 314                 next = d->next;
 315                 dev = d->dev;
 316                 if (d != ic_dev && !netdev_uses_dsa(dev)) {
 317                         pr_debug("IP-Config: Downing %s\n", dev->name);
 318                         dev_change_flags(dev, d->flags, NULL);
 319                 }
 320                 kfree(d);
 321         }
 322         rtnl_unlock();
 323 }
 324
 325 /*
 326  *      Interface to various network functions.
 327  */
 328
 329 static inline void
 330 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
 331 {
 332         sin->sin_family = AF_INET;
 333         sin->sin_addr.s_addr = addr;
 334         sin->sin_port = port;
 335 }
 336
 337 /*
 338  *      Set up interface addresses and routes.
 339  */
 340
 341 static int __init ic_setup_if(void)
 342 {
 343         struct ifreq ir;
 344         struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
 345         int err;
 346
 347         memset(&ir, 0, sizeof(ir));
 348         strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name);
 349         set_sockaddr(sin, ic_myaddr, 0);
 350         if ((err = devinet_ioctl(&init_net, SIOCSIFADDR, &ir)) < 0) {
 351                 pr_err("IP-Config: Unable to set interface address (%d)\n",
 352                        err);
 353                 return -1;
 354         }
 355         set_sockaddr(sin, ic_netmask, 0);
 356         if ((err = devinet_ioctl(&init_net, SIOCSIFNETMASK, &ir)) < 0) {
 357                 pr_err("IP-Config: Unable to set interface netmask (%d)\n",
 358                        err);
 359                 return -1;
 360         }
 361         set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
 362         if ((err = devinet_ioctl(&init_net, SIOCSIFBRDADDR, &ir)) < 0) {
 363                 pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
 364                        err);
 365                 return -1;
 366         }
 367         /* Handle the case where we need non-standard MTU on the boot link (a network
 368          * using jumbo frames, for instance).  If we can't set the mtu, don't error
 369          * out, we'll try to muddle along.
 370          */
 371         if (ic_dev_mtu != 0) {
 372                 rtnl_lock();
 373                 if ((err = dev_set_mtu(ic_dev->dev, ic_dev_mtu)) < 0)
 374                         pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
 375                                ic_dev_mtu, err);
 376                 rtnl_unlock();
 377         }
 378         return 0;
 379 }
 380
 381 static int __init ic_setup_routes(void)
 382 {
 383         /* No need to setup device routes, only the default route... */
 384
 385         if (ic_gateway != NONE) {
 386                 struct rtentry rm;
 387                 int err;
 388
 389                 memset(&rm, 0, sizeof(rm));
 390                 if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
 391                         pr_err("IP-Config: Gateway not on directly connected network\n");
 392                         return -1;
 393                 }
 394                 set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
 395                 set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
 396                 set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
 397                 rm.rt_flags = RTF_UP | RTF_GATEWAY;
 398                 if ((err = ip_rt_ioctl(&init_net, SIOCADDRT, &rm)) < 0) {
 399                         pr_err("IP-Config: Cannot add default route (%d)\n",
 400                                err);
 401                         return -1;
 402                 }
 403         }
 404
 405         return 0;
 406 }
 407
 408 /*
 409  *      Fill in default values for all missing parameters.
 410  */
 411
 412 static int __init ic_defaults(void)
 413 {
 414         /*
 415          *      At this point we have no userspace running so need not
 416          *      claim locks on system_utsname
 417          */
 418
 419         if (!ic_host_name_set)
 420                 sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
 421
 422         if (root_server_addr == NONE)
 423                 root_server_addr = ic_servaddr;
 424
 425         if (ic_netmask == NONE) {
 426                 if (IN_CLASSA(ntohl(ic_myaddr)))
 427                         ic_netmask = htonl(IN_CLASSA_NET);
 428                 else if (IN_CLASSB(ntohl(ic_myaddr)))
 429                         ic_netmask = htonl(IN_CLASSB_NET);
 430                 else if (IN_CLASSC(ntohl(ic_myaddr)))
 431                         ic_netmask = htonl(IN_CLASSC_NET);
 432                 else if (IN_CLASSE(ntohl(ic_myaddr)))
 433                         ic_netmask = htonl(IN_CLASSE_NET);
 434                 else {
 435                         pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
 436                                &ic_myaddr);
 437                         return -1;
 438                 }
 439                 pr_notice("IP-Config: Guessing netmask %pI4\n",
 440                           &ic_netmask);
 441         }
 442
 443         return 0;
 444 }
 445
 446 /*
 447  *      RARP support.
 448  */
 449
 450 #ifdef IPCONFIG_RARP
 451
 452 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
 453
 454 static struct packet_type rarp_packet_type __initdata = {
 455         .type = cpu_to_be16(ETH_P_RARP),
 456         .func = ic_rarp_recv,
 457 };
 458
 459 static inline void __init ic_rarp_init(void)
 460 {
 461         dev_add_pack(&rarp_packet_type);
 462 }
 463
 464 static inline void __init ic_rarp_cleanup(void)
 465 {
 466         dev_remove_pack(&rarp_packet_type);
 467 }
 468
 469 /*
 470  *  Process received RARP packet.
 471  */
 472 static int __init
 473 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 474 {
 475         struct arphdr *rarp;
 476         unsigned char *rarp_ptr;
 477         __be32 sip, tip;
 478         unsigned char *tha;             /* t for "target" */
 479         struct ic_device *d;
 480
 481         if (!net_eq(dev_net(dev), &init_net))
 482                 goto drop;
 483
 484         skb = skb_share_check(skb, GFP_ATOMIC);
 485         if (!skb)
 486                 return NET_RX_DROP;
 487
 488         if (!pskb_may_pull(skb, sizeof(struct arphdr)))
 489                 goto drop;
 490
 491         /* Basic sanity checks can be done without the lock.  */
 492         rarp = (struct arphdr *)skb_transport_header(skb);
 493
 494         /* If this test doesn't pass, it's not IP, or we should
 495          * ignore it anyway.
 496          */
 497         if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
 498                 goto drop;
 499
 500         /* If it's not a RARP reply, delete it. */
 501         if (rarp->ar_op != htons(ARPOP_RREPLY))
 502                 goto drop;
 503
 504         /* If it's not Ethernet, delete it. */
 505         if (rarp->ar_pro != htons(ETH_P_IP))
 506                 goto drop;
 507
 508         if (!pskb_may_pull(skb, arp_hdr_len(dev)))
 509                 goto drop;
 510
 511         /* OK, it is all there and looks valid, process... */
 512         rarp = (struct arphdr *)skb_transport_header(skb);
 513         rarp_ptr = (unsigned char *) (rarp + 1);
 514
 515         /* One reply at a time, please. */
 516         spin_lock(&ic_recv_lock);
 517
 518         /* If we already have a reply, just drop the packet */
 519         if (ic_got_reply)
 520                 goto drop_unlock;
 521
 522         /* Find the ic_device that the packet arrived on */
 523         d = ic_first_dev;
 524         while (d && d->dev != dev)
 525                 d = d->next;
 526         if (!d)
 527                 goto drop_unlock;       /* should never happen */
 528
 529         /* Extract variable-width fields */
 530         rarp_ptr += dev->addr_len;
 531         memcpy(&sip, rarp_ptr, 4);
 532         rarp_ptr += 4;
 533         tha = rarp_ptr;
 534         rarp_ptr += dev->addr_len;
 535         memcpy(&tip, rarp_ptr, 4);
 536
 537         /* Discard packets which are not meant for us. */
 538         if (memcmp(tha, dev->dev_addr, dev->addr_len))
 539                 goto drop_unlock;
 540
 541         /* Discard packets which are not from specified server. */
 542         if (ic_servaddr != NONE && ic_servaddr != sip)
 543                 goto drop_unlock;
 544
 545         /* We have a winner! */
 546         ic_dev = d;
 547         if (ic_myaddr == NONE)
 548                 ic_myaddr = tip;
 549         ic_servaddr = sip;
 550         ic_addrservaddr = sip;
 551         ic_got_reply = IC_RARP;
 552
 553 drop_unlock:
 554         /* Show's over.  Nothing to see here.  */
 555         spin_unlock(&ic_recv_lock);
 556
 557 drop:
 558         /* Throw the packet out. */
 559         kfree_skb(skb);
 560         return 0;
 561 }
 562
 563
 564 /*
 565  *  Send RARP request packet over a single interface.
 566  */
 567 static void __init ic_rarp_send_if(struct ic_device *d)
 568 {
 569         struct net_device *dev = d->dev;
 570         arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
 571                  dev->dev_addr, dev->dev_addr);
 572 }
 573 #endif
 574
 575 /*
 576  *  Predefine Nameservers
 577  */
 578 static inline void __init ic_nameservers_predef(void)
 579 {
 580         int i;
 581
 582         for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
 583                 ic_nameservers[i] = NONE;
 584 }
 585
 586 /* Predefine NTP servers */
 587 static inline void __init ic_ntp_servers_predef(void)
 588 {
 589         int i;
 590
 591         for (i = 0; i < CONF_NTP_SERVERS_MAX; i++)
 592                 ic_ntp_servers[i] = NONE;
 593 }
 594
 595 /*
 596  *      DHCP/BOOTP support.
 597  */
 598
 599 #ifdef IPCONFIG_BOOTP
 600
 601 struct bootp_pkt {              /* BOOTP packet format */
 602         struct iphdr iph;       /* IP header */
 603         struct udphdr udph;     /* UDP header */
 604         u8 op;                  /* 1=request, 2=reply */
 605         u8 htype;               /* HW address type */
 606         u8 hlen;                /* HW address length */
 607         u8 hops;                /* Used only by gateways */
 608         __be32 xid;             /* Transaction ID */
 609         __be16 secs;            /* Seconds since we started */
 610         __be16 flags;           /* Just what it says */
 611         __be32 client_ip;               /* Client's IP address if known */
 612         __be32 your_ip;         /* Assigned IP address */
 613         __be32 server_ip;               /* (Next, e.g. NFS) Server's IP address */
 614         __be32 relay_ip;                /* IP address of BOOTP relay */
 615         u8 hw_addr[16];         /* Client's HW address */
 616         u8 serv_name[64];       /* Server host name */
 617         u8 boot_file[128];      /* Name of boot file */
 618         u8 exten[312];          /* DHCP options / BOOTP vendor extensions */
 619 };
 620
 621 /* packet ops */
 622 #define BOOTP_REQUEST   1
 623 #define BOOTP_REPLY     2
 624
 625 /* DHCP message types */
 626 #define DHCPDISCOVER    1
 627 #define DHCPOFFER       2
 628 #define DHCPREQUEST     3
 629 #define DHCPDECLINE     4
 630 #define DHCPACK         5
 631 #define DHCPNAK         6
 632 #define DHCPRELEASE     7
 633 #define DHCPINFORM      8
 634
 635 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
 636
 637 static struct packet_type bootp_packet_type __initdata = {
 638         .type = cpu_to_be16(ETH_P_IP),
 639         .func = ic_bootp_recv,
 640 };
 641
 642 /*
 643  *  Initialize DHCP/BOOTP extension fields in the request.
 644  */
 645
 646 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
 647
 648 #ifdef IPCONFIG_DHCP
 649
 650 static void __init
 651 ic_dhcp_init_options(u8 *options, struct ic_device *d)
 652 {
 653         u8 mt = ((ic_servaddr == NONE)
 654                  ? DHCPDISCOVER : DHCPREQUEST);
 655         u8 *e = options;
 656         int len;
 657
 658         pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
 659
 660         memcpy(e, ic_bootp_cookie, 4);  /* RFC1048 Magic Cookie */
 661         e += 4;
 662
 663         *e++ = 53;              /* DHCP message type */
 664         *e++ = 1;
 665         *e++ = mt;
 666
 667         if (mt == DHCPREQUEST) {
 668                 *e++ = 54;      /* Server ID (IP address) */
 669                 *e++ = 4;
 670                 memcpy(e, &ic_servaddr, 4);
 671                 e += 4;
 672
 673                 *e++ = 50;      /* Requested IP address */
 674                 *e++ = 4;
 675                 memcpy(e, &ic_myaddr, 4);
 676                 e += 4;
 677         }
 678
 679         /* always? */
 680         {
 681                 static const u8 ic_req_params[] = {
 682                         1,      /* Subnet mask */
 683                         3,      /* Default gateway */
 684                         6,      /* DNS server */
 685                         12,     /* Host name */
 686                         15,     /* Domain name */
 687                         17,     /* Boot path */
 688                         26,     /* MTU */
 689                         40,     /* NIS domain name */
 690                         42,     /* NTP servers */
 691                 };
 692
 693                 *e++ = 55;      /* Parameter request list */
 694                 *e++ = sizeof(ic_req_params);
 695                 memcpy(e, ic_req_params, sizeof(ic_req_params));
 696                 e += sizeof(ic_req_params);
 697
 698                 if (ic_host_name_set) {
 699                         *e++ = 12;      /* host-name */
 700                         len = strlen(utsname()->nodename);
 701                         *e++ = len;
 702                         memcpy(e, utsname()->nodename, len);
 703                         e += len;
 704                 }
 705                 if (*vendor_class_identifier) {
 706                         pr_info("DHCP: sending class identifier \"%s\"\n",
 707                                 vendor_class_identifier);
 708                         *e++ = 60;      /* Class-identifier */
 709                         len = strlen(vendor_class_identifier);
 710                         *e++ = len;
 711                         memcpy(e, vendor_class_identifier, len);
 712                         e += len;
 713                 }
 714                 len = strlen(dhcp_client_identifier + 1);
 715                 /* the minimum length of identifier is 2, include 1 byte type,
 716                  * and can not be larger than the length of options
 717                  */
 718                 if (len >= 1 && len < 312 - (e - options) - 1) {
 719                         *e++ = 61;
 720                         *e++ = len + 1;
 721                         memcpy(e, dhcp_client_identifier, len + 1);
 722                         e += len + 1;
 723                 }
 724         }
 725
 726         *e++ = 255;     /* End of the list */
 727 }
 728
 729 #endif /* IPCONFIG_DHCP */
 730
 731 static void __init ic_bootp_init_ext(u8 *e)
 732 {
 733         memcpy(e, ic_bootp_cookie, 4);  /* RFC1048 Magic Cookie */
 734         e += 4;
 735         *e++ = 1;               /* Subnet mask request */
 736         *e++ = 4;
 737         e += 4;
 738         *e++ = 3;               /* Default gateway request */
 739         *e++ = 4;
 740         e += 4;
 741 #if CONF_NAMESERVERS_MAX > 0
 742         *e++ = 6;               /* (DNS) name server request */
 743         *e++ = 4 * CONF_NAMESERVERS_MAX;
 744         e += 4 * CONF_NAMESERVERS_MAX;
 745 #endif
 746         *e++ = 12;              /* Host name request */
 747         *e++ = 32;
 748         e += 32;
 749         *e++ = 40;              /* NIS Domain name request */
 750         *e++ = 32;
 751         e += 32;
 752         *e++ = 17;              /* Boot path */
 753         *e++ = 40;
 754         e += 40;
 755
 756         *e++ = 57;              /* set extension buffer size for reply */
 757         *e++ = 2;
 758         *e++ = 1;               /* 128+236+8+20+14, see dhcpd sources */
 759         *e++ = 150;
 760
 761         *e++ = 255;             /* End of the list */
 762 }
 763
 764
 765 /*
 766  *  Initialize the DHCP/BOOTP mechanism.
 767  */
 768 static inline void __init ic_bootp_init(void)
 769 {
 770         /* Re-initialise all name servers and NTP servers to NONE, in case any
 771          * were set via the "ip=" or "nfsaddrs=" kernel command line parameters:
 772          * any IP addresses specified there will already have been decoded but
 773          * are no longer needed
 774          */
 775         ic_nameservers_predef();
 776         ic_ntp_servers_predef();
 777
 778         dev_add_pack(&bootp_packet_type);
 779 }
 780
 781
 782 /*
 783  *  DHCP/BOOTP cleanup.
 784  */
 785 static inline void __init ic_bootp_cleanup(void)
 786 {
 787         dev_remove_pack(&bootp_packet_type);
 788 }
 789
 790
 791 /*
 792  *  Send DHCP/BOOTP request to single interface.
 793  */
 794 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
 795 {
 796         struct net_device *dev = d->dev;
 797         struct sk_buff *skb;
 798         struct bootp_pkt *b;
 799         struct iphdr *h;
 800         int hlen = LL_RESERVED_SPACE(dev);
 801         int tlen = dev->needed_tailroom;
 802
 803         /* Allocate packet */
 804         skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
 805                         GFP_KERNEL);
 806         if (!skb)
 807                 return;
 808         skb_reserve(skb, hlen);
 809         b = skb_put_zero(skb, sizeof(struct bootp_pkt));
 810
 811         /* Construct IP header */
 812         skb_reset_network_header(skb);
 813         h = ip_hdr(skb);
 814         h->version = 4;
 815         h->ihl = 5;
 816         h->tot_len = htons(sizeof(struct bootp_pkt));
 817         h->frag_off = htons(IP_DF);
 818         h->ttl = 64;
 819         h->protocol = IPPROTO_UDP;
 820         h->daddr = htonl(INADDR_BROADCAST);
 821         h->check = ip_fast_csum((unsigned char *) h, h->ihl);
 822
 823         /* Construct UDP header */
 824         b->udph.source = htons(68);
 825         b->udph.dest = htons(67);
 826         b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
 827         /* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
 828
 829         /* Construct DHCP/BOOTP header */
 830         b->op = BOOTP_REQUEST;
 831         if (dev->type < 256) /* check for false types */
 832                 b->htype = dev->type;
 833         else if (dev->type == ARPHRD_FDDI)
 834                 b->htype = ARPHRD_ETHER;
 835         else {
 836                 pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
 837                         dev->name);
 838                 b->htype = dev->type; /* can cause undefined behavior */
 839         }
 840
 841         /* server_ip and your_ip address are both already zero per RFC2131 */
 842         b->hlen = dev->addr_len;
 843         memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
 844         b->secs = htons(jiffies_diff / HZ);
 845         b->xid = d->xid;
 846
 847         /* add DHCP options or BOOTP extensions */
 848 #ifdef IPCONFIG_DHCP
 849         if (ic_proto_enabled & IC_USE_DHCP)
 850                 ic_dhcp_init_options(b->exten, d);
 851         else
 852 #endif
 853                 ic_bootp_init_ext(b->exten);
 854
 855         /* Chain packet down the line... */
 856         skb->dev = dev;
 857         skb->protocol = htons(ETH_P_IP);
 858         if (dev_hard_header(skb, dev, ntohs(skb->protocol),
 859                             dev->broadcast, dev->dev_addr, skb->len) < 0) {
 860                 kfree_skb(skb);
 861                 printk("E");
 862                 return;
 863         }
 864
 865         if (dev_queue_xmit(skb) < 0)
 866                 printk("E");
 867 }
 868
 869
 870 /*
 871  *  Copy BOOTP-supplied string if not already set.
 872  */
 873 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
 874 {
 875         if (!len)
 876                 return 0;
 877         if (len > max-1)
 878                 len = max-1;
 879         memcpy(dest, src, len);
 880         dest[len] = '\0';
 881         return 1;
 882 }
 883
 884
 885 /*
 886  *  Process BOOTP extensions.
 887  */
 888 static void __init ic_do_bootp_ext(u8 *ext)
 889 {
 890         u8 servers;
 891         int i;
 892         __be16 mtu;
 893
 894         u8 *c;
 895
 896         pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
 897         for (c=ext+2; c<ext+2+ext[1]; c++)
 898                 pr_debug(" %02x", *c);
 899         pr_debug("\n");
 900
 901         switch (*ext++) {
 902         case 1:         /* Subnet mask */
 903                 if (ic_netmask == NONE)
 904                         memcpy(&ic_netmask, ext+1, 4);
 905                 break;
 906         case 3:         /* Default gateway */
 907                 if (ic_gateway == NONE)
 908                         memcpy(&ic_gateway, ext+1, 4);
 909                 break;
 910         case 6:         /* DNS server */
 911                 servers= *ext/4;
 912                 if (servers > CONF_NAMESERVERS_MAX)
 913                         servers = CONF_NAMESERVERS_MAX;
 914                 for (i = 0; i < servers; i++) {
 915                         if (ic_nameservers[i] == NONE)
 916                                 memcpy(&ic_nameservers[i], ext+1+4*i, 4);
 917                 }
 918                 break;
 919         case 12:        /* Host name */
 920                 ic_bootp_string(utsname()->nodename, ext+1, *ext,
 921                                 __NEW_UTS_LEN);
 922                 ic_host_name_set = 1;
 923                 break;
 924         case 15:        /* Domain name (DNS) */
 925                 ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
 926                 break;
 927         case 17:        /* Root path */
 928                 if (!root_server_path[0])
 929                         ic_bootp_string(root_server_path, ext+1, *ext,
 930                                         sizeof(root_server_path));
 931                 break;
 932         case 26:        /* Interface MTU */
 933                 memcpy(&mtu, ext+1, sizeof(mtu));
 934                 ic_dev_mtu = ntohs(mtu);
 935                 break;
 936         case 40:        /* NIS Domain name (_not_ DNS) */
 937                 ic_bootp_string(utsname()->domainname, ext+1, *ext,
 938                                 __NEW_UTS_LEN);
 939                 break;
 940         case 42:        /* NTP servers */
 941                 servers = *ext / 4;
 942                 if (servers > CONF_NTP_SERVERS_MAX)
 943                         servers = CONF_NTP_SERVERS_MAX;
 944                 for (i = 0; i < servers; i++) {
 945                         if (ic_ntp_servers[i] == NONE)
 946                                 memcpy(&ic_ntp_servers[i], ext+1+4*i, 4);
 947                 }
 948                 break;
 949         }
 950 }
 951
 952
 953 /*
 954  *  Receive BOOTP reply.
 955  */
 956 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 957 {
 958         struct bootp_pkt *b;
 959         struct iphdr *h;
 960         struct ic_device *d;
 961         int len, ext_len;
 962
 963         if (!net_eq(dev_net(dev), &init_net))
 964                 goto drop;
 965
 966         /* Perform verifications before taking the lock.  */
 967         if (skb->pkt_type == PACKET_OTHERHOST)
 968                 goto drop;
 969
 970         skb = skb_share_check(skb, GFP_ATOMIC);
 971         if (!skb)
 972                 return NET_RX_DROP;
 973
 974         if (!pskb_may_pull(skb,
 975                            sizeof(struct iphdr) +
 976                            sizeof(struct udphdr)))
 977                 goto drop;
 978
 979         b = (struct bootp_pkt *)skb_network_header(skb);
 980         h = &b->iph;
 981
 982         if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
 983                 goto drop;
 984
 985         /* Fragments are not supported */
 986         if (ip_is_fragment(h)) {
 987                 net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
 988                 goto drop;
 989         }
 990
 991         if (skb->len < ntohs(h->tot_len))
 992                 goto drop;
 993
 994         if (ip_fast_csum((char *) h, h->ihl))
 995                 goto drop;
 996
 997         if (b->udph.source != htons(67) || b->udph.dest != htons(68))
 998                 goto drop;
 999
1000         if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
1001                 goto drop;
1002
1003         len = ntohs(b->udph.len) - sizeof(struct udphdr);
1004         ext_len = len - (sizeof(*b) -
1005                          sizeof(struct iphdr) -
1006                          sizeof(struct udphdr) -
1007                          sizeof(b->exten));
1008         if (ext_len < 0)
1009                 goto drop;
1010
1011         /* Ok the front looks good, make sure we can get at the rest.  */
1012         if (!pskb_may_pull(skb, skb->len))
1013                 goto drop;
1014
1015         b = (struct bootp_pkt *)skb_network_header(skb);
1016         h = &b->iph;
1017
1018         /* One reply at a time, please. */
1019         spin_lock(&ic_recv_lock);
1020
1021         /* If we already have a reply, just drop the packet */
1022         if (ic_got_reply)
1023                 goto drop_unlock;
1024
1025         /* Find the ic_device that the packet arrived on */
1026         d = ic_first_dev;
1027         while (d && d->dev != dev)
1028                 d = d->next;
1029         if (!d)
1030                 goto drop_unlock;  /* should never happen */
1031
1032         /* Is it a reply to our BOOTP request? */
1033         if (b->op != BOOTP_REPLY ||
1034             b->xid != d->xid) {
1035                 net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1036                                     d->dev->name, b->op, b->xid);
1037                 goto drop_unlock;
1038         }
1039
1040         /* Parse extensions */
1041         if (ext_len >= 4 &&
1042             !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1043                 u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1044                 u8 *ext;
1045
1046 #ifdef IPCONFIG_DHCP
1047                 if (ic_proto_enabled & IC_USE_DHCP) {
1048                         __be32 server_id = NONE;
1049                         int mt = 0;
1050
1051                         ext = &b->exten[4];
1052                         while (ext < end && *ext != 0xff) {
1053                                 u8 *opt = ext++;
1054                                 if (*opt == 0)  /* Padding */
1055                                         continue;
1056                                 ext += *ext + 1;
1057                                 if (ext >= end)
1058                                         break;
1059                                 switch (*opt) {
1060                                 case 53:        /* Message type */
1061                                         if (opt[1])
1062                                                 mt = opt[2];
1063                                         break;
1064                                 case 54:        /* Server ID (IP address) */
1065                                         if (opt[1] >= 4)
1066                                                 memcpy(&server_id, opt + 2, 4);
1067                                         break;
1068                                 }
1069                         }
1070
1071                         pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1072
1073                         switch (mt) {
1074                         case DHCPOFFER:
1075                                 /* While in the process of accepting one offer,
1076                                  * ignore all others.
1077                                  */
1078                                 if (ic_myaddr != NONE)
1079                                         goto drop_unlock;
1080
1081                                 /* Let's accept that offer. */
1082                                 ic_myaddr = b->your_ip;
1083                                 ic_servaddr = server_id;
1084                                 pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1085                                          &ic_myaddr, &b->iph.saddr);
1086                                 /* The DHCP indicated server address takes
1087                                  * precedence over the bootp header one if
1088                                  * they are different.
1089                                  */
1090                                 if ((server_id != NONE) &&
1091                                     (b->server_ip != server_id))
1092                                         b->server_ip = ic_servaddr;
1093                                 break;
1094
1095                         case DHCPACK:
1096                                 if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1097                                         goto drop_unlock;
1098
1099                                 /* Yeah! */
1100                                 break;
1101
1102                         default:
1103                                 /* Urque.  Forget it*/
1104                                 ic_myaddr = NONE;
1105                                 ic_servaddr = NONE;
1106                                 goto drop_unlock;
1107                         }
1108
1109                         ic_dhcp_msgtype = mt;
1110
1111                 }
1112 #endif /* IPCONFIG_DHCP */
1113
1114                 ext = &b->exten[4];
1115                 while (ext < end && *ext != 0xff) {
1116                         u8 *opt = ext++;
1117                         if (*opt == 0)  /* Padding */
1118                                 continue;
1119                         ext += *ext + 1;
1120                         if (ext < end)
1121                                 ic_do_bootp_ext(opt);
1122                 }
1123         }
1124
1125         /* We have a winner! */
1126         ic_dev = d;
1127         ic_myaddr = b->your_ip;
1128         ic_servaddr = b->server_ip;
1129         ic_addrservaddr = b->iph.saddr;
1130         if (ic_gateway == NONE && b->relay_ip)
1131                 ic_gateway = b->relay_ip;
1132         if (ic_nameservers[0] == NONE)
1133                 ic_nameservers[0] = ic_servaddr;
1134         ic_got_reply = IC_BOOTP;
1135
1136 drop_unlock:
1137         /* Show's over.  Nothing to see here.  */
1138         spin_unlock(&ic_recv_lock);
1139
1140 drop:
1141         /* Throw the packet out. */
1142         kfree_skb(skb);
1143
1144         return 0;
1145 }
1146
1147
1148 #endif
1149
1150
1151 /*
1152  *      Dynamic IP configuration -- DHCP, BOOTP, RARP.
1153  */
1154
1155 #ifdef IPCONFIG_DYNAMIC
1156
1157 static int __init ic_dynamic(void)
1158 {
1159         int retries;
1160         struct ic_device *d;
1161         unsigned long start_jiffies, timeout, jiff;
1162         int do_bootp = ic_proto_have_if & IC_BOOTP;
1163         int do_rarp = ic_proto_have_if & IC_RARP;
1164
1165         /*
1166          * If none of DHCP/BOOTP/RARP was selected, return with an error.
1167          * This routine gets only called when some pieces of information
1168          * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1169          */
1170         if (!ic_proto_enabled) {
1171                 pr_err("IP-Config: Incomplete network configuration information\n");
1172                 return -1;
1173         }
1174
1175 #ifdef IPCONFIG_BOOTP
1176         if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1177                 pr_err("DHCP/BOOTP: No suitable device found\n");
1178 #endif
1179 #ifdef IPCONFIG_RARP
1180         if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1181                 pr_err("RARP: No suitable device found\n");
1182 #endif
1183
1184         if (!ic_proto_have_if)
1185                 /* Error message already printed */
1186                 return -1;
1187
1188         /*
1189          * Setup protocols
1190          */
1191 #ifdef IPCONFIG_BOOTP
1192         if (do_bootp)
1193                 ic_bootp_init();
1194 #endif
1195 #ifdef IPCONFIG_RARP
1196         if (do_rarp)
1197                 ic_rarp_init();
1198 #endif
1199
1200         /*
1201          * Send requests and wait, until we get an answer. This loop
1202          * seems to be a terrible waste of CPU time, but actually there is
1203          * only one process running at all, so we don't need to use any
1204          * scheduler functions.
1205          * [Actually we could now, but the nothing else running note still
1206          *  applies.. - AC]
1207          */
1208         pr_notice("Sending %s%s%s requests .",
1209                   do_bootp
1210                   ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1211                   (do_bootp && do_rarp) ? " and " : "",
1212                   do_rarp ? "RARP" : "");
1213
1214         start_jiffies = jiffies;
1215         d = ic_first_dev;
1216         retries = CONF_SEND_RETRIES;
1217         get_random_bytes(&timeout, sizeof(timeout));
1218         timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1219         for (;;) {
1220 #ifdef IPCONFIG_BOOTP
1221                 if (do_bootp && (d->able & IC_BOOTP))
1222                         ic_bootp_send_if(d, jiffies - start_jiffies);
1223 #endif
1224 #ifdef IPCONFIG_RARP
1225                 if (do_rarp && (d->able & IC_RARP))
1226                         ic_rarp_send_if(d);
1227 #endif
1228
1229                 if (!d->next) {
1230                         jiff = jiffies + timeout;
1231                         while (time_before(jiffies, jiff) && !ic_got_reply)
1232                                 schedule_timeout_uninterruptible(1);
1233                 }
1234 #ifdef IPCONFIG_DHCP
1235                 /* DHCP isn't done until we get a DHCPACK. */
1236                 if ((ic_got_reply & IC_BOOTP) &&
1237                     (ic_proto_enabled & IC_USE_DHCP) &&
1238                     ic_dhcp_msgtype != DHCPACK) {
1239                         ic_got_reply = 0;
1240                         /* continue on device that got the reply */
1241                         d = ic_dev;
1242                         pr_cont(",");
1243                         continue;
1244                 }
1245 #endif /* IPCONFIG_DHCP */
1246
1247                 if (ic_got_reply) {
1248                         pr_cont(" OK\n");
1249                         break;
1250                 }
1251
1252                 if ((d = d->next))
1253                         continue;
1254
1255                 if (! --retries) {
1256                         pr_cont(" timed out!\n");
1257                         break;
1258                 }
1259
1260                 d = ic_first_dev;
1261
1262                 timeout = timeout CONF_TIMEOUT_MULT;
1263                 if (timeout > CONF_TIMEOUT_MAX)
1264                         timeout = CONF_TIMEOUT_MAX;
1265
1266                 pr_cont(".");
1267         }
1268
1269 #ifdef IPCONFIG_BOOTP
1270         if (do_bootp)
1271                 ic_bootp_cleanup();
1272 #endif
1273 #ifdef IPCONFIG_RARP
1274         if (do_rarp)
1275                 ic_rarp_cleanup();
1276 #endif
1277
1278         if (!ic_got_reply) {
1279                 ic_myaddr = NONE;
1280                 return -1;
1281         }
1282
1283         pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1284                 ((ic_got_reply & IC_RARP) ? "RARP"
1285                 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1286                 &ic_addrservaddr, &ic_myaddr);
1287
1288         return 0;
1289 }
1290
1291 #endif /* IPCONFIG_DYNAMIC */
1292
1293 #ifdef CONFIG_PROC_FS
1294 /* proc_dir_entry for /proc/net/ipconfig */
1295 static struct proc_dir_entry *ipconfig_dir;
1296
1297 /* Name servers: */
1298 static int pnp_seq_show(struct seq_file *seq, void *v)
1299 {
1300         int i;
1301
1302         if (ic_proto_used & IC_PROTO)
1303                 seq_printf(seq, "#PROTO: %s\n",
1304                            (ic_proto_used & IC_RARP) ? "RARP"
1305                            : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1306         else
1307                 seq_puts(seq, "#MANUAL\n");
1308
1309         if (ic_domain[0])
1310                 seq_printf(seq,
1311                            "domain %s\n", ic_domain);
1312         for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1313                 if (ic_nameservers[i] != NONE)
1314                         seq_printf(seq, "nameserver %pI4\n",
1315                                    &ic_nameservers[i]);
1316         }
1317         if (ic_servaddr != NONE)
1318                 seq_printf(seq, "bootserver %pI4\n",
1319                            &ic_servaddr);
1320         return 0;
1321 }
1322
1323 /* Create the /proc/net/ipconfig directory */
1324 static int __init ipconfig_proc_net_init(void)
1325 {
1326         ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net);
1327         if (!ipconfig_dir)
1328                 return -ENOMEM;
1329
1330         return 0;
1331 }
1332
1333 /* Create a new file under /proc/net/ipconfig */
1334 static int ipconfig_proc_net_create(const char *name,
1335                                     const struct file_operations *fops)
1336 {
1337         char *pname;
1338         struct proc_dir_entry *p;
1339
1340         if (!ipconfig_dir)
1341                 return -ENOMEM;
1342
1343         pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name);
1344         if (!pname)
1345                 return -ENOMEM;
1346
1347         p = proc_create(pname, 0444, init_net.proc_net, fops);
1348         kfree(pname);
1349         if (!p)
1350                 return -ENOMEM;
1351
1352         return 0;
1353 }
1354
1355 /* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */
1356 static int ntp_servers_seq_show(struct seq_file *seq, void *v)
1357 {
1358         int i;
1359
1360         for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1361                 if (ic_ntp_servers[i] != NONE)
1362                         seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]);
1363         }
1364         return 0;
1365 }
1366 DEFINE_SHOW_ATTRIBUTE(ntp_servers_seq);
1367 #endif /* CONFIG_PROC_FS */
1368
1369 /*
1370  *  Extract IP address from the parameter string if needed. Note that we
1371  *  need to have root_server_addr set _before_ IPConfig gets called as it
1372  *  can override it.
1373  */
1374 __be32 __init root_nfs_parse_addr(char *name)
1375 {
1376         __be32 addr;
1377         int octets = 0;
1378         char *cp, *cq;
1379
1380         cp = cq = name;
1381         while (octets < 4) {
1382                 while (*cp >= '0' && *cp <= '9')
1383                         cp++;
1384                 if (cp == cq || cp - cq > 3)
1385                         break;
1386                 if (*cp == '.' || octets == 3)
1387                         octets++;
1388                 if (octets < 4)
1389                         cp++;
1390                 cq = cp;
1391         }
1392         if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1393                 if (*cp == ':')
1394                         *cp++ = '\0';
1395                 addr = in_aton(name);
1396                 memmove(name, cp, strlen(cp) + 1);
1397         } else
1398                 addr = NONE;
1399
1400         return addr;
1401 }
1402
1403 #define DEVICE_WAIT_MAX         12 /* 12 seconds */
1404
1405 static int __init wait_for_devices(void)
1406 {
1407         int i;
1408
1409         for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1410                 struct net_device *dev;
1411                 int found = 0;
1412
1413                 rtnl_lock();
1414                 for_each_netdev(&init_net, dev) {
1415                         if (ic_is_init_dev(dev)) {
1416                                 found = 1;
1417                                 break;
1418                         }
1419                 }
1420                 rtnl_unlock();
1421                 if (found)
1422                         return 0;
1423                 ssleep(1);
1424         }
1425         return -ENODEV;
1426 }
1427
1428 /*
1429  *      IP Autoconfig dispatcher.
1430  */
1431
1432 static int __init ip_auto_config(void)
1433 {
1434         __be32 addr;
1435 #ifdef IPCONFIG_DYNAMIC
1436         int retries = CONF_OPEN_RETRIES;
1437 #endif
1438         int err;
1439         unsigned int i;
1440
1441         /* Initialise all name servers and NTP servers to NONE (but only if the
1442          * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded,
1443          * otherwise we'll overwrite the IP addresses specified there)
1444          */
1445         if (ic_set_manually == 0) {
1446                 ic_nameservers_predef();
1447                 ic_ntp_servers_predef();
1448         }
1449
1450 #ifdef CONFIG_PROC_FS
1451         proc_create_single("pnp", 0444, init_net.proc_net, pnp_seq_show);
1452
1453         if (ipconfig_proc_net_init() == 0)
1454                 ipconfig_proc_net_create("ntp_servers", &ntp_servers_seq_fops);
1455 #endif /* CONFIG_PROC_FS */
1456
1457         if (!ic_enable)
1458                 return 0;
1459
1460         pr_debug("IP-Config: Entered.\n");
1461 #ifdef IPCONFIG_DYNAMIC
1462  try_try_again:
1463 #endif
1464         /* Wait for devices to appear */
1465         err = wait_for_devices();
1466         if (err)
1467                 return err;
1468
1469         /* Setup all network devices */
1470         err = ic_open_devs();
1471         if (err)
1472                 return err;
1473
1474         /* Give drivers a chance to settle */
1475         msleep(CONF_POST_OPEN);
1476
1477         /*
1478          * If the config information is insufficient (e.g., our IP address or
1479          * IP address of the boot server is missing or we have multiple network
1480          * interfaces and no default was set), use BOOTP or RARP to get the
1481          * missing values.
1482          */
1483         if (ic_myaddr == NONE ||
1484 #ifdef CONFIG_ROOT_NFS
1485             (root_server_addr == NONE &&
1486              ic_servaddr == NONE &&
1487              ROOT_DEV == Root_NFS) ||
1488 #endif
1489             ic_first_dev->next) {
1490 #ifdef IPCONFIG_DYNAMIC
1491                 if (ic_dynamic() < 0) {
1492                         ic_close_devs();
1493
1494                         /*
1495                          * I don't know why, but sometimes the
1496                          * eepro100 driver (at least) gets upset and
1497                          * doesn't work the first time it's opened.
1498                          * But then if you close it and reopen it, it
1499                          * works just fine.  So we need to try that at
1500                          * least once before giving up.
1501                          *
1502                          * Also, if the root will be NFS-mounted, we
1503                          * have nowhere to go if DHCP fails.  So we
1504                          * just have to keep trying forever.
1505                          *
1506                          *                              -- Chip
1507                          */
1508 #ifdef CONFIG_ROOT_NFS
1509                         if (ROOT_DEV ==  Root_NFS) {
1510                                 pr_err("IP-Config: Retrying forever (NFS root)...\n");
1511                                 goto try_try_again;
1512                         }
1513 #endif
1514
1515                         if (--retries) {
1516                                 pr_err("IP-Config: Reopening network devices...\n");
1517                                 goto try_try_again;
1518                         }
1519
1520                         /* Oh, well.  At least we tried. */
1521                         pr_err("IP-Config: Auto-configuration of network failed\n");
1522                         return -1;
1523                 }
1524 #else /* !DYNAMIC */
1525                 pr_err("IP-Config: Incomplete network configuration information\n");
1526                 ic_close_devs();
1527                 return -1;
1528 #endif /* IPCONFIG_DYNAMIC */
1529         } else {
1530                 /* Device selected manually or only one device -> use it */
1531                 ic_dev = ic_first_dev;
1532         }
1533
1534         addr = root_nfs_parse_addr(root_server_path);
1535         if (root_server_addr == NONE)
1536                 root_server_addr = addr;
1537
1538         /*
1539          * Use defaults wherever applicable.
1540          */
1541         if (ic_defaults() < 0)
1542                 return -1;
1543
1544         /*
1545          * Record which protocol was actually used.
1546          */
1547 #ifdef IPCONFIG_DYNAMIC
1548         ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1549 #endif
1550
1551 #ifndef IPCONFIG_SILENT
1552         /*
1553          * Clue in the operator.
1554          */
1555         pr_info("IP-Config: Complete:\n");
1556
1557         pr_info("     device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1558                 ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1559                 &ic_myaddr, &ic_netmask, &ic_gateway);
1560         pr_info("     host=%s, domain=%s, nis-domain=%s\n",
1561                 utsname()->nodename, ic_domain, utsname()->domainname);
1562         pr_info("     bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1563                 &ic_servaddr, &root_server_addr, root_server_path);
1564         if (ic_dev_mtu)
1565                 pr_cont(", mtu=%d", ic_dev_mtu);
1566         /* Name servers (if any): */
1567         for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1568                 if (ic_nameservers[i] != NONE) {
1569                         if (i == 0)
1570                                 pr_info("     nameserver%u=%pI4",
1571                                         i, &ic_nameservers[i]);
1572                         else
1573                                 pr_cont(", nameserver%u=%pI4",
1574                                         i, &ic_nameservers[i]);
1575                 }
1576                 if (i + 1 == CONF_NAMESERVERS_MAX)
1577                         pr_cont("\n");
1578         }
1579         /* NTP servers (if any): */
1580         for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1581                 if (ic_ntp_servers[i] != NONE) {
1582                         if (i == 0)
1583                                 pr_info("     ntpserver%u=%pI4",
1584                                         i, &ic_ntp_servers[i]);
1585                         else
1586                                 pr_cont(", ntpserver%u=%pI4",
1587                                         i, &ic_ntp_servers[i]);
1588                 }
1589                 if (i + 1 == CONF_NTP_SERVERS_MAX)
1590                         pr_cont("\n");
1591         }
1592 #endif /* !SILENT */
1593
1594         /*
1595          * Close all network devices except the device we've
1596          * autoconfigured and set up routes.
1597          */
1598         if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1599                 err = -1;
1600         else
1601                 err = 0;
1602
1603         ic_close_devs();
1604
1605         return err;
1606 }
1607
1608 late_initcall(ip_auto_config);
1609
1610
1611 /*
1612  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1613  *  command line parameter.  See Documentation/filesystems/nfs/nfsroot.txt.
1614  */
1615 static int __init ic_proto_name(char *name)
1616 {
1617         if (!strcmp(name, "on") || !strcmp(name, "any")) {
1618                 return 1;
1619         }
1620         if (!strcmp(name, "off") || !strcmp(name, "none")) {
1621                 return 0;
1622         }
1623 #ifdef CONFIG_IP_PNP_DHCP
1624         else if (!strncmp(name, "dhcp", 4)) {
1625                 char *client_id;
1626
1627                 ic_proto_enabled &= ~IC_RARP;
1628                 client_id = strstr(name, "dhcp,");
1629                 if (client_id) {
1630                         char *v;
1631
1632                         client_id = client_id + 5;
1633                         v = strchr(client_id, ',');
1634                         if (!v)
1635                                 return 1;
1636                         *v = 0;
1637                         if (kstrtou8(client_id, 0, dhcp_client_identifier))
1638                                 pr_debug("DHCP: Invalid client identifier type\n");
1639                         strncpy(dhcp_client_identifier + 1, v + 1, 251);
1640                         *v = ',';
1641                 }
1642                 return 1;
1643         }
1644 #endif
1645 #ifdef CONFIG_IP_PNP_BOOTP
1646         else if (!strcmp(name, "bootp")) {
1647                 ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1648                 return 1;
1649         }
1650 #endif
1651 #ifdef CONFIG_IP_PNP_RARP
1652         else if (!strcmp(name, "rarp")) {
1653                 ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1654                 return 1;
1655         }
1656 #endif
1657 #ifdef IPCONFIG_DYNAMIC
1658         else if (!strcmp(name, "both")) {
1659                 ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1660                 return 1;
1661         }
1662 #endif
1663         return 0;
1664 }
1665
1666 static int __init ip_auto_config_setup(char *addrs)
1667 {
1668         char *cp, *ip, *dp;
1669         int num = 0;
1670
1671         ic_set_manually = 1;
1672         ic_enable = 1;
1673
1674         /*
1675          * If any dhcp, bootp etc options are set, leave autoconfig on
1676          * and skip the below static IP processing.
1677          */
1678         if (ic_proto_name(addrs))
1679                 return 1;
1680
1681         /* If no static IP is given, turn off autoconfig and bail.  */
1682         if (*addrs == 0 ||
1683             strcmp(addrs, "off") == 0 ||
1684             strcmp(addrs, "none") == 0) {
1685                 ic_enable = 0;
1686                 return 1;
1687         }
1688
1689         /* Initialise all name servers and NTP servers to NONE */
1690         ic_nameservers_predef();
1691         ic_ntp_servers_predef();
1692
1693         /* Parse string for static IP assignment.  */
1694         ip = addrs;
1695         while (ip && *ip) {
1696                 if ((cp = strchr(ip, ':')))
1697                         *cp++ = '\0';
1698                 if (strlen(ip) > 0) {
1699                         pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1700                         switch (num) {
1701                         case 0:
1702                                 if ((ic_myaddr = in_aton(ip)) == ANY)
1703                                         ic_myaddr = NONE;
1704                                 break;
1705                         case 1:
1706                                 if ((ic_servaddr = in_aton(ip)) == ANY)
1707                                         ic_servaddr = NONE;
1708                                 break;
1709                         case 2:
1710                                 if ((ic_gateway = in_aton(ip)) == ANY)
1711                                         ic_gateway = NONE;
1712                                 break;
1713                         case 3:
1714                                 if ((ic_netmask = in_aton(ip)) == ANY)
1715                                         ic_netmask = NONE;
1716                                 break;
1717                         case 4:
1718                                 if ((dp = strchr(ip, '.'))) {
1719                                         *dp++ = '\0';
1720                                         strlcpy(utsname()->domainname, dp,
1721                                                 sizeof(utsname()->domainname));
1722                                 }
1723                                 strlcpy(utsname()->nodename, ip,
1724                                         sizeof(utsname()->nodename));
1725                                 ic_host_name_set = 1;
1726                                 break;
1727                         case 5:
1728                                 strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1729                                 break;
1730                         case 6:
1731                                 if (ic_proto_name(ip) == 0 &&
1732                                     ic_myaddr == NONE) {
1733                                         ic_enable = 0;
1734                                 }
1735                                 break;
1736                         case 7:
1737                                 if (CONF_NAMESERVERS_MAX >= 1) {
1738                                         ic_nameservers[0] = in_aton(ip);
1739                                         if (ic_nameservers[0] == ANY)
1740                                                 ic_nameservers[0] = NONE;
1741                                 }
1742                                 break;
1743                         case 8:
1744                                 if (CONF_NAMESERVERS_MAX >= 2) {
1745                                         ic_nameservers[1] = in_aton(ip);
1746                                         if (ic_nameservers[1] == ANY)
1747                                                 ic_nameservers[1] = NONE;
1748                                 }
1749                                 break;
1750                         case 9:
1751                                 if (CONF_NTP_SERVERS_MAX >= 1) {
1752                                         ic_ntp_servers[0] = in_aton(ip);
1753                                         if (ic_ntp_servers[0] == ANY)
1754                                                 ic_ntp_servers[0] = NONE;
1755                                 }
1756                                 break;
1757                         }
1758                 }
1759                 ip = cp;
1760                 num++;
1761         }
1762
1763         return 1;
1764 }
1765 __setup("ip=", ip_auto_config_setup);
1766
1767 static int __init nfsaddrs_config_setup(char *addrs)
1768 {
1769         return ip_auto_config_setup(addrs);
1770 }
1771 __setup("nfsaddrs=", nfsaddrs_config_setup);
1772
1773 static int __init vendor_class_identifier_setup(char *addrs)
1774 {
1775         if (strlcpy(vendor_class_identifier, addrs,
1776                     sizeof(vendor_class_identifier))
1777             >= sizeof(vendor_class_identifier))
1778                 pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1779                         vendor_class_identifier);
1780         return 1;
1781 }
1782 __setup("dhcpclass=", vendor_class_identifier_setup);