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
  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 */
 104 static 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  */
 114 int ic_set_manually __initdata = 0;             /* IPconfig parameters set manually */
 115
 116 static int ic_enable __initdata;                /* IP config enabled? */
 117
 118 /* Protocol choice */
 119 int 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
 131 static int ic_host_name_set __initdata; /* Host name set by us? */
 132
 133 __be32 ic_myaddr = NONE;                /* My IP address */
 134 static __be32 ic_netmask = NONE;        /* Netmask for local subnet */
 135 __be32 ic_gateway = NONE;       /* Gateway IP address */
 136
 137 #ifdef IPCONFIG_DYNAMIC
 138 static __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 */
 144 u8 root_server_path[256] = { 0, };      /* Path to mount as root */
 145
 146 /* vendor class identifier */
 147 static char vendor_class_identifier[253] __initdata;
 148
 149 #if defined(CONFIG_IP_PNP_DHCP)
 150 static char dhcp_client_identifier[253] __initdata;
 151 #endif
 152
 153 /* Persistent data: */
 154
 155 #ifdef IPCONFIG_DYNAMIC
 156 static int ic_proto_used;                       /* Protocol used, if any */
 157 #else
 158 #define ic_proto_used 0
 159 #endif
 160 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
 161 static __be32 ic_ntp_servers[CONF_NTP_SERVERS_MAX]; /* NTP server IP addresses */
 162 static u8 ic_domain[64];                /* DNS (not NIS) domain name */
 163
 164 /*
 165  * Private state.
 166  */
 167
 168 /* Name of user-selected boot device */
 169 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
 170
 171 /* Protocols supported by available interfaces */
 172 static int ic_proto_have_if __initdata;
 173
 174 /* MTU for boot device */
 175 static int ic_dev_mtu __initdata;
 176
 177 #ifdef IPCONFIG_DYNAMIC
 178 static DEFINE_SPINLOCK(ic_recv_lock);
 179 static volatile int ic_got_reply __initdata;    /* Proto(s) that replied */
 180 #endif
 181 #ifdef IPCONFIG_DHCP
 182 static int ic_dhcp_msgtype __initdata;  /* DHCP msg type received */
 183 #endif
 184
 185
 186 /*
 187  *      Network devices
 188  */
 189
 190 struct ic_device {
 191         struct ic_device *next;
 192         struct net_device *dev;
 193         unsigned short flags;
 194         short able;
 195         __be32 xid;
 196 };
 197
 198 static struct ic_device *ic_first_dev __initdata;       /* List of open device */
 199 static struct ic_device *ic_dev __initdata;             /* Selected device */
 200
 201 static 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
 211 static 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         }
 292 have_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
 308 static 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
 331 static inline void
 332 set_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
 343 static 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
 383 static 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
 414 static 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
 454 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
 455
 456 static struct packet_type rarp_packet_type __initdata = {
 457         .type = cpu_to_be16(ETH_P_RARP),
 458         .func = ic_rarp_recv,
 459 };
 460
 461 static inline void __init ic_rarp_init(void)
 462 {
 463         dev_add_pack(&rarp_packet_type);
 464 }
 465
 466 static inline void __init ic_rarp_cleanup(void)
 467 {
 468         dev_remove_pack(&rarp_packet_type);
 469 }
 470
 471 /*
 472  *  Process received RARP packet.
 473  */
 474 static int __init
 475 ic_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
 555 drop_unlock:
 556         /* Show's over.  Nothing to see here.  */
 557         spin_unlock(&ic_recv_lock);
 558
 559 drop:
 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  */
 569 static 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  */
 580 static 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 */
 589 static 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
 603 struct 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
 637 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
 638
 639 static 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
 648 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
 649
 650 #ifdef IPCONFIG_DHCP
 651
 652 static void __init
 653 ic_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
 733 static 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  */
 770 static 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  */
 787 static 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  */
 796 static 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
 874  */
 875 static 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  */
 890 static 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                 if (!ic_host_name_set) {
 923                         ic_bootp_string(utsname()->nodename, ext+1, *ext,
 924                                         __NEW_UTS_LEN);
 925                         ic_host_name_set = 1;
 926                 }
 927                 break;
 928         case 15:        /* Domain name (DNS) */
 929                 if (!ic_domain[0])
 930                         ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
 931                 break;
 932         case 17:        /* Root path */
 933                 if (!root_server_path[0])
 934                         ic_bootp_string(root_server_path, ext+1, *ext,
 935                                         sizeof(root_server_path));
 936                 break;
 937         case 26:        /* Interface MTU */
 938                 memcpy(&mtu, ext+1, sizeof(mtu));
 939                 ic_dev_mtu = ntohs(mtu);
 940                 break;
 941         case 40:        /* NIS Domain name (_not_ DNS) */
 942                 ic_bootp_string(utsname()->domainname, ext+1, *ext,
 943                                 __NEW_UTS_LEN);
 944                 break;
 945         case 42:        /* NTP servers */
 946                 servers = *ext / 4;
 947                 if (servers > CONF_NTP_SERVERS_MAX)
 948                         servers = CONF_NTP_SERVERS_MAX;
 949                 for (i = 0; i < servers; i++) {
 950                         if (ic_ntp_servers[i] == NONE)
 951                                 memcpy(&ic_ntp_servers[i], ext+1+4*i, 4);
 952                 }
 953                 break;
 954         }
 955 }
 956
 957
 958 /*
 959  *  Receive BOOTP reply.
 960  */
 961 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 962 {
 963         struct bootp_pkt *b;
 964         struct iphdr *h;
 965         struct ic_device *d;
 966         int len, ext_len;
 967
 968         if (!net_eq(dev_net(dev), &init_net))
 969                 goto drop;
 970
 971         /* Perform verifications before taking the lock.  */
 972         if (skb->pkt_type == PACKET_OTHERHOST)
 973                 goto drop;
 974
 975         skb = skb_share_check(skb, GFP_ATOMIC);
 976         if (!skb)
 977                 return NET_RX_DROP;
 978
 979         if (!pskb_may_pull(skb,
 980                            sizeof(struct iphdr) +
 981                            sizeof(struct udphdr)))
 982                 goto drop;
 983
 984         b = (struct bootp_pkt *)skb_network_header(skb);
 985         h = &b->iph;
 986
 987         if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
 988                 goto drop;
 989
 990         /* Fragments are not supported */
 991         if (ip_is_fragment(h)) {
 992                 net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
 993                 goto drop;
 994         }
 995
 996         if (skb->len < ntohs(h->tot_len))
 997                 goto drop;
 998
 999         if (ip_fast_csum((char *) h, h->ihl))
1000                 goto drop;
1001
1002         if (b->udph.source != htons(67) || b->udph.dest != htons(68))
1003                 goto drop;
1004
1005         if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
1006                 goto drop;
1007
1008         len = ntohs(b->udph.len) - sizeof(struct udphdr);
1009         ext_len = len - (sizeof(*b) -
1010                          sizeof(struct iphdr) -
1011                          sizeof(struct udphdr) -
1012                          sizeof(b->exten));
1013         if (ext_len < 0)
1014                 goto drop;
1015
1016         /* Ok the front looks good, make sure we can get at the rest.  */
1017         if (!pskb_may_pull(skb, skb->len))
1018                 goto drop;
1019
1020         b = (struct bootp_pkt *)skb_network_header(skb);
1021         h = &b->iph;
1022
1023         /* One reply at a time, please. */
1024         spin_lock(&ic_recv_lock);
1025
1026         /* If we already have a reply, just drop the packet */
1027         if (ic_got_reply)
1028                 goto drop_unlock;
1029
1030         /* Find the ic_device that the packet arrived on */
1031         d = ic_first_dev;
1032         while (d && d->dev != dev)
1033                 d = d->next;
1034         if (!d)
1035                 goto drop_unlock;  /* should never happen */
1036
1037         /* Is it a reply to our BOOTP request? */
1038         if (b->op != BOOTP_REPLY ||
1039             b->xid != d->xid) {
1040                 net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1041                                     d->dev->name, b->op, b->xid);
1042                 goto drop_unlock;
1043         }
1044
1045         /* Parse extensions */
1046         if (ext_len >= 4 &&
1047             !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1048                 u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1049                 u8 *ext;
1050
1051 #ifdef IPCONFIG_DHCP
1052                 if (ic_proto_enabled & IC_USE_DHCP) {
1053                         __be32 server_id = NONE;
1054                         int mt = 0;
1055
1056                         ext = &b->exten[4];
1057                         while (ext < end && *ext != 0xff) {
1058                                 u8 *opt = ext++;
1059                                 if (*opt == 0)  /* Padding */
1060                                         continue;
1061                                 ext += *ext + 1;
1062                                 if (ext >= end)
1063                                         break;
1064                                 switch (*opt) {
1065                                 case 53:        /* Message type */
1066                                         if (opt[1])
1067                                                 mt = opt[2];
1068                                         break;
1069                                 case 54:        /* Server ID (IP address) */
1070                                         if (opt[1] >= 4)
1071                                                 memcpy(&server_id, opt + 2, 4);
1072                                         break;
1073                                 }
1074                         }
1075
1076                         pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1077
1078                         switch (mt) {
1079                         case DHCPOFFER:
1080                                 /* While in the process of accepting one offer,
1081                                  * ignore all others.
1082                                  */
1083                                 if (ic_myaddr != NONE)
1084                                         goto drop_unlock;
1085
1086                                 /* Let's accept that offer. */
1087                                 ic_myaddr = b->your_ip;
1088                                 ic_servaddr = server_id;
1089                                 pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1090                                          &ic_myaddr, &b->iph.saddr);
1091                                 /* The DHCP indicated server address takes
1092                                  * precedence over the bootp header one if
1093                                  * they are different.
1094                                  */
1095                                 if ((server_id != NONE) &&
1096                                     (b->server_ip != server_id))
1097                                         b->server_ip = ic_servaddr;
1098                                 break;
1099
1100                         case DHCPACK:
1101                                 if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1102                                         goto drop_unlock;
1103
1104                                 /* Yeah! */
1105                                 break;
1106
1107                         default:
1108                                 /* Urque.  Forget it*/
1109                                 ic_myaddr = NONE;
1110                                 ic_servaddr = NONE;
1111                                 goto drop_unlock;
1112                         }
1113
1114                         ic_dhcp_msgtype = mt;
1115
1116                 }
1117 #endif /* IPCONFIG_DHCP */
1118
1119                 ext = &b->exten[4];
1120                 while (ext < end && *ext != 0xff) {
1121                         u8 *opt = ext++;
1122                         if (*opt == 0)  /* Padding */
1123                                 continue;
1124                         ext += *ext + 1;
1125                         if (ext < end)
1126                                 ic_do_bootp_ext(opt);
1127                 }
1128         }
1129
1130         /* We have a winner! */
1131         ic_dev = d;
1132         ic_myaddr = b->your_ip;
1133         ic_servaddr = b->server_ip;
1134         ic_addrservaddr = b->iph.saddr;
1135         if (ic_gateway == NONE && b->relay_ip)
1136                 ic_gateway = b->relay_ip;
1137         if (ic_nameservers[0] == NONE)
1138                 ic_nameservers[0] = ic_servaddr;
1139         ic_got_reply = IC_BOOTP;
1140
1141 drop_unlock:
1142         /* Show's over.  Nothing to see here.  */
1143         spin_unlock(&ic_recv_lock);
1144
1145 drop:
1146         /* Throw the packet out. */
1147         kfree_skb(skb);
1148
1149         return 0;
1150 }
1151
1152
1153 #endif
1154
1155
1156 /*
1157  *      Dynamic IP configuration -- DHCP, BOOTP, RARP.
1158  */
1159
1160 #ifdef IPCONFIG_DYNAMIC
1161
1162 static int __init ic_dynamic(void)
1163 {
1164         int retries;
1165         struct ic_device *d;
1166         unsigned long start_jiffies, timeout, jiff;
1167         int do_bootp = ic_proto_have_if & IC_BOOTP;
1168         int do_rarp = ic_proto_have_if & IC_RARP;
1169
1170         /*
1171          * If none of DHCP/BOOTP/RARP was selected, return with an error.
1172          * This routine gets only called when some pieces of information
1173          * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1174          */
1175         if (!ic_proto_enabled) {
1176                 pr_err("IP-Config: Incomplete network configuration information\n");
1177                 return -1;
1178         }
1179
1180 #ifdef IPCONFIG_BOOTP
1181         if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1182                 pr_err("DHCP/BOOTP: No suitable device found\n");
1183 #endif
1184 #ifdef IPCONFIG_RARP
1185         if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1186                 pr_err("RARP: No suitable device found\n");
1187 #endif
1188
1189         if (!ic_proto_have_if)
1190                 /* Error message already printed */
1191                 return -1;
1192
1193         /*
1194          * Setup protocols
1195          */
1196 #ifdef IPCONFIG_BOOTP
1197         if (do_bootp)
1198                 ic_bootp_init();
1199 #endif
1200 #ifdef IPCONFIG_RARP
1201         if (do_rarp)
1202                 ic_rarp_init();
1203 #endif
1204
1205         /*
1206          * Send requests and wait, until we get an answer. This loop
1207          * seems to be a terrible waste of CPU time, but actually there is
1208          * only one process running at all, so we don't need to use any
1209          * scheduler functions.
1210          * [Actually we could now, but the nothing else running note still
1211          *  applies.. - AC]
1212          */
1213         pr_notice("Sending %s%s%s requests .",
1214                   do_bootp
1215                   ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1216                   (do_bootp && do_rarp) ? " and " : "",
1217                   do_rarp ? "RARP" : "");
1218
1219         start_jiffies = jiffies;
1220         d = ic_first_dev;
1221         retries = CONF_SEND_RETRIES;
1222         get_random_bytes(&timeout, sizeof(timeout));
1223         timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1224         for (;;) {
1225 #ifdef IPCONFIG_BOOTP
1226                 if (do_bootp && (d->able & IC_BOOTP))
1227                         ic_bootp_send_if(d, jiffies - start_jiffies);
1228 #endif
1229 #ifdef IPCONFIG_RARP
1230                 if (do_rarp && (d->able & IC_RARP))
1231                         ic_rarp_send_if(d);
1232 #endif
1233
1234                 if (!d->next) {
1235                         jiff = jiffies + timeout;
1236                         while (time_before(jiffies, jiff) && !ic_got_reply)
1237                                 schedule_timeout_uninterruptible(1);
1238                 }
1239 #ifdef IPCONFIG_DHCP
1240                 /* DHCP isn't done until we get a DHCPACK. */
1241                 if ((ic_got_reply & IC_BOOTP) &&
1242                     (ic_proto_enabled & IC_USE_DHCP) &&
1243                     ic_dhcp_msgtype != DHCPACK) {
1244                         ic_got_reply = 0;
1245                         /* continue on device that got the reply */
1246                         d = ic_dev;
1247                         pr_cont(",");
1248                         continue;
1249                 }
1250 #endif /* IPCONFIG_DHCP */
1251
1252                 if (ic_got_reply) {
1253                         pr_cont(" OK\n");
1254                         break;
1255                 }
1256
1257                 if ((d = d->next))
1258                         continue;
1259
1260                 if (! --retries) {
1261                         pr_cont(" timed out!\n");
1262                         break;
1263                 }
1264
1265                 d = ic_first_dev;
1266
1267                 timeout = timeout CONF_TIMEOUT_MULT;
1268                 if (timeout > CONF_TIMEOUT_MAX)
1269                         timeout = CONF_TIMEOUT_MAX;
1270
1271                 pr_cont(".");
1272         }
1273
1274 #ifdef IPCONFIG_BOOTP
1275         if (do_bootp)
1276                 ic_bootp_cleanup();
1277 #endif
1278 #ifdef IPCONFIG_RARP
1279         if (do_rarp)
1280                 ic_rarp_cleanup();
1281 #endif
1282
1283         if (!ic_got_reply) {
1284                 ic_myaddr = NONE;
1285                 return -1;
1286         }
1287
1288         pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1289                 ((ic_got_reply & IC_RARP) ? "RARP"
1290                 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1291                 &ic_addrservaddr, &ic_myaddr);
1292
1293         return 0;
1294 }
1295
1296 #endif /* IPCONFIG_DYNAMIC */
1297
1298 #ifdef CONFIG_PROC_FS
1299 /* proc_dir_entry for /proc/net/ipconfig */
1300 static struct proc_dir_entry *ipconfig_dir;
1301
1302 /* Name servers: */
1303 static int pnp_seq_show(struct seq_file *seq, void *v)
1304 {
1305         int i;
1306
1307         if (ic_proto_used & IC_PROTO)
1308                 seq_printf(seq, "#PROTO: %s\n",
1309                            (ic_proto_used & IC_RARP) ? "RARP"
1310                            : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1311         else
1312                 seq_puts(seq, "#MANUAL\n");
1313
1314         if (ic_domain[0])
1315                 seq_printf(seq,
1316                            "domain %s\n", ic_domain);
1317         for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1318                 if (ic_nameservers[i] != NONE)
1319                         seq_printf(seq, "nameserver %pI4\n",
1320                                    &ic_nameservers[i]);
1321         }
1322         if (ic_servaddr != NONE)
1323                 seq_printf(seq, "bootserver %pI4\n",
1324                            &ic_servaddr);
1325         return 0;
1326 }
1327
1328 /* Create the /proc/net/ipconfig directory */
1329 static int __init ipconfig_proc_net_init(void)
1330 {
1331         ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net);
1332         if (!ipconfig_dir)
1333                 return -ENOMEM;
1334
1335         return 0;
1336 }
1337
1338 /* Create a new file under /proc/net/ipconfig */
1339 static int ipconfig_proc_net_create(const char *name,
1340                                     const struct file_operations *fops)
1341 {
1342         char *pname;
1343         struct proc_dir_entry *p;
1344
1345         if (!ipconfig_dir)
1346                 return -ENOMEM;
1347
1348         pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name);
1349         if (!pname)
1350                 return -ENOMEM;
1351
1352         p = proc_create(pname, 0444, init_net.proc_net, fops);
1353         kfree(pname);
1354         if (!p)
1355                 return -ENOMEM;
1356
1357         return 0;
1358 }
1359
1360 /* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */
1361 static int ntp_servers_seq_show(struct seq_file *seq, void *v)
1362 {
1363         int i;
1364
1365         for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1366                 if (ic_ntp_servers[i] != NONE)
1367                         seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]);
1368         }
1369         return 0;
1370 }
1371 DEFINE_SHOW_ATTRIBUTE(ntp_servers_seq);
1372 #endif /* CONFIG_PROC_FS */
1373
1374 /*
1375  *  Extract IP address from the parameter string if needed. Note that we
1376  *  need to have root_server_addr set _before_ IPConfig gets called as it
1377  *  can override it.
1378  */
1379 __be32 __init root_nfs_parse_addr(char *name)
1380 {
1381         __be32 addr;
1382         int octets = 0;
1383         char *cp, *cq;
1384
1385         cp = cq = name;
1386         while (octets < 4) {
1387                 while (*cp >= '0' && *cp <= '9')
1388                         cp++;
1389                 if (cp == cq || cp - cq > 3)
1390                         break;
1391                 if (*cp == '.' || octets == 3)
1392                         octets++;
1393                 if (octets < 4)
1394                         cp++;
1395                 cq = cp;
1396         }
1397         if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1398                 if (*cp == ':')
1399                         *cp++ = '\0';
1400                 addr = in_aton(name);
1401                 memmove(name, cp, strlen(cp) + 1);
1402         } else
1403                 addr = NONE;
1404
1405         return addr;
1406 }
1407
1408 #define DEVICE_WAIT_MAX         12 /* 12 seconds */
1409
1410 static int __init wait_for_devices(void)
1411 {
1412         int i;
1413
1414         for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1415                 struct net_device *dev;
1416                 int found = 0;
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
1437 static 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_seq_fops);
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 #ifdef CONFIG_ROOT_NFS
1490             (root_server_addr == NONE &&
1491              ic_servaddr == NONE &&
1492              ROOT_DEV == Root_NFS) ||
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
1520                         if (--retries) {
1521                                 pr_err("IP-Config: Reopening network devices...\n");
1522                                 goto try_try_again;
1523                         }
1524
1525                         /* Oh, well.  At least we tried. */
1526                         pr_err("IP-Config: Auto-configuration of network failed\n");
1527                         return -1;
1528                 }
1529 #else /* !DYNAMIC */
1530                 pr_err("IP-Config: Incomplete network configuration information\n");
1531                 ic_close_devs();
1532                 return -1;
1533 #endif /* IPCONFIG_DYNAMIC */
1534         } else {
1535                 /* Device selected manually or only one device -> use it */
1536                 ic_dev = ic_first_dev;
1537         }
1538
1539         addr = root_nfs_parse_addr(root_server_path);
1540         if (root_server_addr == NONE)
1541                 root_server_addr = addr;
1542
1543         /*
1544          * Use defaults wherever applicable.
1545          */
1546         if (ic_defaults() < 0)
1547                 return -1;
1548
1549         /*
1550          * Record which protocol was actually used.
1551          */
1552 #ifdef IPCONFIG_DYNAMIC
1553         ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1554 #endif
1555
1556 #ifndef IPCONFIG_SILENT
1557         /*
1558          * Clue in the operator.
1559          */
1560         pr_info("IP-Config: Complete:\n");
1561
1562         pr_info("     device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1563                 ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1564                 &ic_myaddr, &ic_netmask, &ic_gateway);
1565         pr_info("     host=%s, domain=%s, nis-domain=%s\n",
1566                 utsname()->nodename, ic_domain, utsname()->domainname);
1567         pr_info("     bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1568                 &ic_servaddr, &root_server_addr, root_server_path);
1569         if (ic_dev_mtu)
1570                 pr_cont(", mtu=%d", ic_dev_mtu);
1571         /* Name servers (if any): */
1572         for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1573                 if (ic_nameservers[i] != NONE) {
1574                         if (i == 0)
1575                                 pr_info("     nameserver%u=%pI4",
1576                                         i, &ic_nameservers[i]);
1577                         else
1578                                 pr_cont(", nameserver%u=%pI4",
1579                                         i, &ic_nameservers[i]);
1580                 }
1581                 if (i + 1 == CONF_NAMESERVERS_MAX)
1582                         pr_cont("\n");
1583         }
1584         /* NTP servers (if any): */
1585         for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1586                 if (ic_ntp_servers[i] != NONE) {
1587                         if (i == 0)
1588                                 pr_info("     ntpserver%u=%pI4",
1589                                         i, &ic_ntp_servers[i]);
1590                         else
1591                                 pr_cont(", ntpserver%u=%pI4",
1592                                         i, &ic_ntp_servers[i]);
1593                 }
1594                 if (i + 1 == CONF_NTP_SERVERS_MAX)
1595                         pr_cont("\n");
1596         }
1597 #endif /* !SILENT */
1598
1599         /*
1600          * Close all network devices except the device we've
1601          * autoconfigured and set up routes.
1602          */
1603         if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1604                 err = -1;
1605         else
1606                 err = 0;
1607
1608         ic_close_devs();
1609
1610         return err;
1611 }
1612
1613 late_initcall(ip_auto_config);
1614
1615
1616 /*
1617  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1618  *  command line parameter.  See Documentation/filesystems/nfs/nfsroot.txt.
1619  */
1620 static int __init ic_proto_name(char *name)
1621 {
1622         if (!strcmp(name, "on") || !strcmp(name, "any")) {
1623                 return 1;
1624         }
1625         if (!strcmp(name, "off") || !strcmp(name, "none")) {
1626                 return 0;
1627         }
1628 #ifdef CONFIG_IP_PNP_DHCP
1629         else if (!strncmp(name, "dhcp", 4)) {
1630                 char *client_id;
1631
1632                 ic_proto_enabled &= ~IC_RARP;
1633                 client_id = strstr(name, "dhcp,");
1634                 if (client_id) {
1635                         char *v;
1636
1637                         client_id = client_id + 5;
1638                         v = strchr(client_id, ',');
1639                         if (!v)
1640                                 return 1;
1641                         *v = 0;
1642                         if (kstrtou8(client_id, 0, dhcp_client_identifier))
1643                                 pr_debug("DHCP: Invalid client identifier type\n");
1644                         strncpy(dhcp_client_identifier + 1, v + 1, 251);
1645                         *v = ',';
1646                 }
1647                 return 1;
1648         }
1649 #endif
1650 #ifdef CONFIG_IP_PNP_BOOTP
1651         else if (!strcmp(name, "bootp")) {
1652                 ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1653                 return 1;
1654         }
1655 #endif
1656 #ifdef CONFIG_IP_PNP_RARP
1657         else if (!strcmp(name, "rarp")) {
1658                 ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1659                 return 1;
1660         }
1661 #endif
1662 #ifdef IPCONFIG_DYNAMIC
1663         else if (!strcmp(name, "both")) {
1664                 ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1665                 return 1;
1666         }
1667 #endif
1668         return 0;
1669 }
1670
1671 static int __init ip_auto_config_setup(char *addrs)
1672 {
1673         char *cp, *ip, *dp;
1674         int num = 0;
1675
1676         ic_set_manually = 1;
1677         ic_enable = 1;
1678
1679         /*
1680          * If any dhcp, bootp etc options are set, leave autoconfig on
1681          * and skip the below static IP processing.
1682          */
1683         if (ic_proto_name(addrs))
1684                 return 1;
1685
1686         /* If no static IP is given, turn off autoconfig and bail.  */
1687         if (*addrs == 0 ||
1688             strcmp(addrs, "off") == 0 ||
1689             strcmp(addrs, "none") == 0) {
1690                 ic_enable = 0;
1691                 return 1;
1692         }
1693
1694         /* Initialise all name servers and NTP servers to NONE */
1695         ic_nameservers_predef();
1696         ic_ntp_servers_predef();
1697
1698         /* Parse string for static IP assignment.  */
1699         ip = addrs;
1700         while (ip && *ip) {
1701                 if ((cp = strchr(ip, ':')))
1702                         *cp++ = '\0';
1703                 if (strlen(ip) > 0) {
1704                         pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1705                         switch (num) {
1706                         case 0:
1707                                 if ((ic_myaddr = in_aton(ip)) == ANY)
1708                                         ic_myaddr = NONE;
1709                                 break;
1710                         case 1:
1711                                 if ((ic_servaddr = in_aton(ip)) == ANY)
1712                                         ic_servaddr = NONE;
1713                                 break;
1714                         case 2:
1715                                 if ((ic_gateway = in_aton(ip)) == ANY)
1716                                         ic_gateway = NONE;
1717                                 break;
1718                         case 3:
1719                                 if ((ic_netmask = in_aton(ip)) == ANY)
1720                                         ic_netmask = NONE;
1721                                 break;
1722                         case 4:
1723                                 if ((dp = strchr(ip, '.'))) {
1724                                         *dp++ = '\0';
1725                                         strlcpy(utsname()->domainname, dp,
1726                                                 sizeof(utsname()->domainname));
1727                                 }
1728                                 strlcpy(utsname()->nodename, ip,
1729                                         sizeof(utsname()->nodename));
1730                                 ic_host_name_set = 1;
1731                                 break;
1732                         case 5:
1733                                 strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1734                                 break;
1735                         case 6:
1736                                 if (ic_proto_name(ip) == 0 &&
1737                                     ic_myaddr == NONE) {
1738                                         ic_enable = 0;
1739                                 }
1740                                 break;
1741                         case 7:
1742                                 if (CONF_NAMESERVERS_MAX >= 1) {
1743                                         ic_nameservers[0] = in_aton(ip);
1744                                         if (ic_nameservers[0] == ANY)
1745                                                 ic_nameservers[0] = NONE;
1746                                 }
1747                                 break;
1748                         case 8:
1749                                 if (CONF_NAMESERVERS_MAX >= 2) {
1750                                         ic_nameservers[1] = in_aton(ip);
1751                                         if (ic_nameservers[1] == ANY)
1752                                                 ic_nameservers[1] = NONE;
1753                                 }
1754                                 break;
1755                         case 9:
1756                                 if (CONF_NTP_SERVERS_MAX >= 1) {
1757                                         ic_ntp_servers[0] = in_aton(ip);
1758                                         if (ic_ntp_servers[0] == ANY)
1759                                                 ic_ntp_servers[0] = NONE;
1760                                 }
1761                                 break;
1762                         }
1763                 }
1764                 ip = cp;
1765                 num++;
1766         }
1767
1768         return 1;
1769 }
1770 __setup("ip=", ip_auto_config_setup);
1771
1772 static int __init nfsaddrs_config_setup(char *addrs)
1773 {
1774         return ip_auto_config_setup(addrs);
1775 }
1776 __setup("nfsaddrs=", nfsaddrs_config_setup);
1777
1778 static int __init vendor_class_identifier_setup(char *addrs)
1779 {
1780         if (strlcpy(vendor_class_identifier, addrs,
1781                     sizeof(vendor_class_identifier))
1782             >= sizeof(vendor_class_identifier))
1783                 pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1784                         vendor_class_identifier);
1785         return 1;
1786 }
1787 __setup("dhcpclass=", vendor_class_identifier_setup);
1788
1789 static int __init set_carrier_timeout(char *str)
1790 {
1791         ssize_t ret;
1792
1793         if (!str)
1794                 return 0;
1795
1796         ret = kstrtouint(str, 0, &carrier_timeout);
1797         if (ret)
1798                 return 0;
1799
1800         return 1;
1801 }
1802 __setup("carrier_timeout=", set_carrier_timeout);