ipconfig.c 37.8 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623
/*
 *  Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or
 *  user-supplied information to configure own IP address and routes.
 *
 *  Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
 *
 *  Derived from network configuration code in fs/nfs/nfsroot.c,
 *  originally Copyright (C) 1995, 1996 Gero Kuhlmann and me.
 *
 *  BOOTP rewritten to construct and analyse packets itself instead
 *  of misusing the IP layer. num_bugs_causing_wrong_arp_replies--;
 *					     -- MJ, December 1998
 *
 *  Fixed ip_auto_config_setup calling at startup in the new "Linker Magic"
 *  initialization scheme.
 *	- Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999
 *
 *  DHCP support added.  To users this looks like a whole separate
 *  protocol, but we know it's just a bag on the side of BOOTP.
 *		-- Chip Salzenberg <chip@valinux.com>, May 2000
 *
 *  Ported DHCP support from 2.2.16 to 2.4.0-test4
 *              -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000
 *
 *  Merged changes from 2.2.19 into 2.4.3
 *              -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001
 *
 *  Multiple Nameservers in /proc/net/pnp
 *              --  Josef Siemes <jsiemes@web.de>, Aug 2002
 */

#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/random.h>
#include <linux/init.h>
#include <linux/utsname.h>
#include <linux/in.h>
#include <linux/if.h>
#include <linux/inet.h>
#include <linux/inetdevice.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/socket.h>
#include <linux/route.h>
#include <linux/udp.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/major.h>
#include <linux/root_dev.h>
#include <linux/delay.h>
#include <linux/nfs_fs.h>
#include <linux/slab.h>
#include <net/net_namespace.h>
#include <net/arp.h>
#include <net/ip.h>
#include <net/ipconfig.h>
#include <net/route.h>

#include <asm/uaccess.h>
#include <net/checksum.h>
#include <asm/processor.h>

/* Define this to allow debugging output */
#undef IPCONFIG_DEBUG

#ifdef IPCONFIG_DEBUG
#define DBG(x) printk x
#else
#define DBG(x) do { } while(0)
#endif

#if defined(CONFIG_IP_PNP_DHCP)
#define IPCONFIG_DHCP
#endif
#if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
#define IPCONFIG_BOOTP
#endif
#if defined(CONFIG_IP_PNP_RARP)
#define IPCONFIG_RARP
#endif
#if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
#define IPCONFIG_DYNAMIC
#endif

/* Define the friendly delay before and after opening net devices */
#define CONF_PRE_OPEN		500	/* Before opening: 1/2 second */
#define CONF_POST_OPEN		1	/* After opening: 1 second */

/* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
#define CONF_OPEN_RETRIES 	2	/* (Re)open devices twice */
#define CONF_SEND_RETRIES 	6	/* Send six requests per open */
#define CONF_INTER_TIMEOUT	(HZ/2)	/* Inter-device timeout: 1/2 second */
#define CONF_BASE_TIMEOUT	(HZ*2)	/* Initial timeout: 2 seconds */
#define CONF_TIMEOUT_RANDOM	(HZ)	/* Maximum amount of randomization */
#define CONF_TIMEOUT_MULT	*7/4	/* Rate of timeout growth */
#define CONF_TIMEOUT_MAX	(HZ*30)	/* Maximum allowed timeout */
#define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
					   - '3' from resolv.h */

#define NONE cpu_to_be32(INADDR_NONE)
#define ANY cpu_to_be32(INADDR_ANY)

/*
 * Public IP configuration
 */

/* This is used by platforms which might be able to set the ipconfig
 * variables using firmware environment vars.  If this is set, it will
 * ignore such firmware variables.
 */
int ic_set_manually __initdata = 0;		/* IPconfig parameters set manually */

static int ic_enable __initdata = 0;		/* IP config enabled? */

/* Protocol choice */
int ic_proto_enabled __initdata = 0
#ifdef IPCONFIG_BOOTP
			| IC_BOOTP
#endif
#ifdef CONFIG_IP_PNP_DHCP
			| IC_USE_DHCP
#endif
#ifdef IPCONFIG_RARP
			| IC_RARP
#endif
			;

static int ic_host_name_set __initdata = 0;	/* Host name set by us? */

__be32 ic_myaddr = NONE;		/* My IP address */
static __be32 ic_netmask = NONE;	/* Netmask for local subnet */
__be32 ic_gateway = NONE;	/* Gateway IP address */

__be32 ic_servaddr = NONE;	/* Boot server IP address */

__be32 root_server_addr = NONE;	/* Address of NFS server */
u8 root_server_path[256] = { 0, };	/* Path to mount as root */

u32 ic_dev_xid;		/* Device under configuration */

/* vendor class identifier */
static char vendor_class_identifier[253] __initdata;

/* Persistent data: */

static int ic_proto_used;			/* Protocol used, if any */
static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
static u8 ic_domain[64];		/* DNS (not NIS) domain name */

/*
 * Private state.
 */

/* Name of user-selected boot device */
static char user_dev_name[IFNAMSIZ] __initdata = { 0, };

/* Protocols supported by available interfaces */
static int ic_proto_have_if __initdata = 0;

/* MTU for boot device */
static int ic_dev_mtu __initdata = 0;

#ifdef IPCONFIG_DYNAMIC
static DEFINE_SPINLOCK(ic_recv_lock);
static volatile int ic_got_reply __initdata = 0;    /* Proto(s) that replied */
#endif
#ifdef IPCONFIG_DHCP
static int ic_dhcp_msgtype __initdata = 0;	/* DHCP msg type received */
#endif


/*
 *	Network devices
 */

struct ic_device {
	struct ic_device *next;
	struct net_device *dev;
	unsigned short flags;
	short able;
	__be32 xid;
};

static struct ic_device *ic_first_dev __initdata = NULL;/* List of open device */
static struct net_device *ic_dev __initdata = NULL;	/* Selected device */

static bool __init ic_device_match(struct net_device *dev)
{
	if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
	    (!(dev->flags & IFF_LOOPBACK) &&
	     (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
	     strncmp(dev->name, "dummy", 5)))
		return true;
	return false;
}

static int __init ic_open_devs(void)
{
	struct ic_device *d, **last;
	struct net_device *dev;
	unsigned short oflags;

	last = &ic_first_dev;
	rtnl_lock();

	/* bring loopback device up first */
	for_each_netdev(&init_net, dev) {
		if (!(dev->flags & IFF_LOOPBACK))
			continue;
		if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
			printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
	}

	for_each_netdev(&init_net, dev) {
		if (dev->flags & IFF_LOOPBACK)
			continue;
		if (ic_device_match(dev)) {
			int able = 0;
			if (dev->mtu >= 364)
				able |= IC_BOOTP;
			else
				printk(KERN_WARNING "DHCP/BOOTP: Ignoring device %s, MTU %d too small", dev->name, dev->mtu);
			if (!(dev->flags & IFF_NOARP))
				able |= IC_RARP;
			able &= ic_proto_enabled;
			if (ic_proto_enabled && !able)
				continue;
			oflags = dev->flags;
			if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
				printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
				continue;
			}
			if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
				rtnl_unlock();
				return -ENOMEM;
			}
			d->dev = dev;
			*last = d;
			last = &d->next;
			d->flags = oflags;
			d->able = able;
			if (able & IC_BOOTP)
				get_random_bytes(&d->xid, sizeof(__be32));
			else
				d->xid = 0;
			ic_proto_have_if |= able;
			DBG(("IP-Config: %s UP (able=%d, xid=%08x)\n",
				dev->name, able, d->xid));
		}
	}
	rtnl_unlock();

	*last = NULL;

	if (!ic_first_dev) {
		if (user_dev_name[0])
			printk(KERN_ERR "IP-Config: Device `%s' not found.\n", user_dev_name);
		else
			printk(KERN_ERR "IP-Config: No network devices available.\n");
		return -ENODEV;
	}
	return 0;
}

static void __init ic_close_devs(void)
{
	struct ic_device *d, *next;
	struct net_device *dev;

	rtnl_lock();
	next = ic_first_dev;
	while ((d = next)) {
		next = d->next;
		dev = d->dev;
		if (dev != ic_dev) {
			DBG(("IP-Config: Downing %s\n", dev->name));
			dev_change_flags(dev, d->flags);
		}
		kfree(d);
	}
	rtnl_unlock();
}

/*
 *	Interface to various network functions.
 */

static inline void
set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
{
	sin->sin_family = AF_INET;
	sin->sin_addr.s_addr = addr;
	sin->sin_port = port;
}

static int __init ic_devinet_ioctl(unsigned int cmd, struct ifreq *arg)
{
	int res;

	mm_segment_t oldfs = get_fs();
	set_fs(get_ds());
	res = devinet_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
	set_fs(oldfs);
	return res;
}

static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
{
	int res;

	mm_segment_t oldfs = get_fs();
	set_fs(get_ds());
	res = dev_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
	set_fs(oldfs);
	return res;
}

static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg)
{
	int res;

	mm_segment_t oldfs = get_fs();
	set_fs(get_ds());
	res = ip_rt_ioctl(&init_net, cmd, (void __user *) arg);
	set_fs(oldfs);
	return res;
}

/*
 *	Set up interface addresses and routes.
 */

static int __init ic_setup_if(void)
{
	struct ifreq ir;
	struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
	int err;

	memset(&ir, 0, sizeof(ir));
	strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->name);
	set_sockaddr(sin, ic_myaddr, 0);
	if ((err = ic_devinet_ioctl(SIOCSIFADDR, &ir)) < 0) {
		printk(KERN_ERR "IP-Config: Unable to set interface address (%d).\n", err);
		return -1;
	}
	set_sockaddr(sin, ic_netmask, 0);
	if ((err = ic_devinet_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
		printk(KERN_ERR "IP-Config: Unable to set interface netmask (%d).\n", err);
		return -1;
	}
	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
	if ((err = ic_devinet_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
		printk(KERN_ERR "IP-Config: Unable to set interface broadcast address (%d).\n", err);
		return -1;
	}
	/* Handle the case where we need non-standard MTU on the boot link (a network
	 * using jumbo frames, for instance).  If we can't set the mtu, don't error
	 * out, we'll try to muddle along.
	 */
	if (ic_dev_mtu != 0) {
		strcpy(ir.ifr_name, ic_dev->name);
		ir.ifr_mtu = ic_dev_mtu;
		if ((err = ic_dev_ioctl(SIOCSIFMTU, &ir)) < 0)
			printk(KERN_ERR "IP-Config: Unable to set interface mtu to %d (%d).\n",
			                 ic_dev_mtu, err);
	}
	return 0;
}

static int __init ic_setup_routes(void)
{
	/* No need to setup device routes, only the default route... */

	if (ic_gateway != NONE) {
		struct rtentry rm;
		int err;

		memset(&rm, 0, sizeof(rm));
		if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
			printk(KERN_ERR "IP-Config: Gateway not on directly connected network.\n");
			return -1;
		}
		set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
		set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
		set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
		rm.rt_flags = RTF_UP | RTF_GATEWAY;
		if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) {
			printk(KERN_ERR "IP-Config: Cannot add default route (%d).\n", err);
			return -1;
		}
	}

	return 0;
}

/*
 *	Fill in default values for all missing parameters.
 */

static int __init ic_defaults(void)
{
	/*
	 *	At this point we have no userspace running so need not
	 *	claim locks on system_utsname
	 */

	if (!ic_host_name_set)
		sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);

	if (root_server_addr == NONE)
		root_server_addr = ic_servaddr;

	if (ic_netmask == NONE) {
		if (IN_CLASSA(ntohl(ic_myaddr)))
			ic_netmask = htonl(IN_CLASSA_NET);
		else if (IN_CLASSB(ntohl(ic_myaddr)))
			ic_netmask = htonl(IN_CLASSB_NET);
		else if (IN_CLASSC(ntohl(ic_myaddr)))
			ic_netmask = htonl(IN_CLASSC_NET);
		else {
			printk(KERN_ERR "IP-Config: Unable to guess netmask for address %pI4\n",
				&ic_myaddr);
			return -1;
		}
		printk("IP-Config: Guessing netmask %pI4\n", &ic_netmask);
	}

	return 0;
}

/*
 *	RARP support.
 */

#ifdef IPCONFIG_RARP

static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);

static struct packet_type rarp_packet_type __initdata = {
	.type =	cpu_to_be16(ETH_P_RARP),
	.func =	ic_rarp_recv,
};

static inline void __init ic_rarp_init(void)
{
	dev_add_pack(&rarp_packet_type);
}

static inline void __init ic_rarp_cleanup(void)
{
	dev_remove_pack(&rarp_packet_type);
}

/*
 *  Process received RARP packet.
 */
static int __init
ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
{
	struct arphdr *rarp;
	unsigned char *rarp_ptr;
	__be32 sip, tip;
	unsigned char *sha, *tha;		/* s for "source", t for "target" */
	struct ic_device *d;

	if (!net_eq(dev_net(dev), &init_net))
		goto drop;

	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
		return NET_RX_DROP;

	if (!pskb_may_pull(skb, sizeof(struct arphdr)))
		goto drop;

	/* Basic sanity checks can be done without the lock.  */
	rarp = (struct arphdr *)skb_transport_header(skb);

	/* If this test doesn't pass, it's not IP, or we should
	 * ignore it anyway.
	 */
	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
		goto drop;

	/* If it's not a RARP reply, delete it. */
	if (rarp->ar_op != htons(ARPOP_RREPLY))
		goto drop;

	/* If it's not Ethernet, delete it. */
	if (rarp->ar_pro != htons(ETH_P_IP))
		goto drop;

	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
		goto drop;

	/* OK, it is all there and looks valid, process... */
	rarp = (struct arphdr *)skb_transport_header(skb);
	rarp_ptr = (unsigned char *) (rarp + 1);

	/* One reply at a time, please. */
	spin_lock(&ic_recv_lock);

	/* If we already have a reply, just drop the packet */
	if (ic_got_reply)
		goto drop_unlock;

	/* Find the ic_device that the packet arrived on */
	d = ic_first_dev;
	while (d && d->dev != dev)
		d = d->next;
	if (!d)
		goto drop_unlock;	/* should never happen */

	/* Extract variable-width fields */
	sha = rarp_ptr;
	rarp_ptr += dev->addr_len;
	memcpy(&sip, rarp_ptr, 4);
	rarp_ptr += 4;
	tha = rarp_ptr;
	rarp_ptr += dev->addr_len;
	memcpy(&tip, rarp_ptr, 4);

	/* Discard packets which are not meant for us. */
	if (memcmp(tha, dev->dev_addr, dev->addr_len))
		goto drop_unlock;

	/* Discard packets which are not from specified server. */
	if (ic_servaddr != NONE && ic_servaddr != sip)
		goto drop_unlock;

	/* We have a winner! */
	ic_dev = dev;
	if (ic_myaddr == NONE)
		ic_myaddr = tip;
	ic_servaddr = sip;
	ic_got_reply = IC_RARP;

drop_unlock:
	/* Show's over.  Nothing to see here.  */
	spin_unlock(&ic_recv_lock);

drop:
	/* Throw the packet out. */
	kfree_skb(skb);
	return 0;
}


/*
 *  Send RARP request packet over a single interface.
 */
static void __init ic_rarp_send_if(struct ic_device *d)
{
	struct net_device *dev = d->dev;
	arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
		 dev->dev_addr, dev->dev_addr);
}
#endif

/*
 *	DHCP/BOOTP support.
 */

#ifdef IPCONFIG_BOOTP

struct bootp_pkt {		/* BOOTP packet format */
	struct iphdr iph;	/* IP header */
	struct udphdr udph;	/* UDP header */
	u8 op;			/* 1=request, 2=reply */
	u8 htype;		/* HW address type */
	u8 hlen;		/* HW address length */
	u8 hops;		/* Used only by gateways */
	__be32 xid;		/* Transaction ID */
	__be16 secs;		/* Seconds since we started */
	__be16 flags;		/* Just what it says */
	__be32 client_ip;		/* Client's IP address if known */
	__be32 your_ip;		/* Assigned IP address */
	__be32 server_ip;		/* (Next, e.g. NFS) Server's IP address */
	__be32 relay_ip;		/* IP address of BOOTP relay */
	u8 hw_addr[16];		/* Client's HW address */
	u8 serv_name[64];	/* Server host name */
	u8 boot_file[128];	/* Name of boot file */
	u8 exten[312];		/* DHCP options / BOOTP vendor extensions */
};

/* packet ops */
#define BOOTP_REQUEST	1
#define BOOTP_REPLY	2

/* DHCP message types */
#define DHCPDISCOVER	1
#define DHCPOFFER	2
#define DHCPREQUEST	3
#define DHCPDECLINE	4
#define DHCPACK		5
#define DHCPNAK		6
#define DHCPRELEASE	7
#define DHCPINFORM	8

static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);

static struct packet_type bootp_packet_type __initdata = {
	.type =	cpu_to_be16(ETH_P_IP),
	.func =	ic_bootp_recv,
};


/*
 *  Initialize DHCP/BOOTP extension fields in the request.
 */

static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };

#ifdef IPCONFIG_DHCP

static void __init
ic_dhcp_init_options(u8 *options)
{
	u8 mt = ((ic_servaddr == NONE)
		 ? DHCPDISCOVER : DHCPREQUEST);
	u8 *e = options;
	int len;

#ifdef IPCONFIG_DEBUG
	printk("DHCP: Sending message type %d\n", mt);
#endif

	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
	e += 4;

	*e++ = 53;		/* DHCP message type */
	*e++ = 1;
	*e++ = mt;

	if (mt == DHCPREQUEST) {
		*e++ = 54;	/* Server ID (IP address) */
		*e++ = 4;
		memcpy(e, &ic_servaddr, 4);
		e += 4;

		*e++ = 50;	/* Requested IP address */
		*e++ = 4;
		memcpy(e, &ic_myaddr, 4);
		e += 4;
	}

	/* always? */
	{
		static const u8 ic_req_params[] = {
			1,	/* Subnet mask */
			3,	/* Default gateway */
			6,	/* DNS server */
			12,	/* Host name */
			15,	/* Domain name */
			17,	/* Boot path */
			26,	/* MTU */
			40,	/* NIS domain name */
		};

		*e++ = 55;	/* Parameter request list */
		*e++ = sizeof(ic_req_params);
		memcpy(e, ic_req_params, sizeof(ic_req_params));
		e += sizeof(ic_req_params);

		if (ic_host_name_set) {
			*e++ = 12;	/* host-name */
			len = strlen(utsname()->nodename);
			*e++ = len;
			memcpy(e, utsname()->nodename, len);
			e += len;
		}
		if (*vendor_class_identifier) {
			printk(KERN_INFO "DHCP: sending class identifier \"%s\"\n",
			       vendor_class_identifier);
			*e++ = 60;	/* Class-identifier */
			len = strlen(vendor_class_identifier);
			*e++ = len;
			memcpy(e, vendor_class_identifier, len);
			e += len;
		}
	}

	*e++ = 255;	/* End of the list */
}

#endif /* IPCONFIG_DHCP */

static void __init ic_bootp_init_ext(u8 *e)
{
	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
	e += 4;
	*e++ = 1;		/* Subnet mask request */
	*e++ = 4;
	e += 4;
	*e++ = 3;		/* Default gateway request */
	*e++ = 4;
	e += 4;
	*e++ = 5;		/* Name server request */
	*e++ = 8;
	e += 8;
	*e++ = 12;		/* Host name request */
	*e++ = 32;
	e += 32;
	*e++ = 40;		/* NIS Domain name request */
	*e++ = 32;
	e += 32;
	*e++ = 17;		/* Boot path */
	*e++ = 40;
	e += 40;

	*e++ = 57;		/* set extension buffer size for reply */
	*e++ = 2;
	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
	*e++ = 150;

	*e++ = 255;		/* End of the list */
}


/*
 *  Initialize the DHCP/BOOTP mechanism.
 */
static inline void __init ic_bootp_init(void)
{
	int i;

	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
		ic_nameservers[i] = NONE;

	dev_add_pack(&bootp_packet_type);
}


/*
 *  DHCP/BOOTP cleanup.
 */
static inline void __init ic_bootp_cleanup(void)
{
	dev_remove_pack(&bootp_packet_type);
}


/*
 *  Send DHCP/BOOTP request to single interface.
 */
static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
{
	struct net_device *dev = d->dev;
	struct sk_buff *skb;
	struct bootp_pkt *b;
	struct iphdr *h;

	/* Allocate packet */
	skb = alloc_skb(sizeof(struct bootp_pkt) + LL_ALLOCATED_SPACE(dev) + 15,
			GFP_KERNEL);
	if (!skb)
		return;
	skb_reserve(skb, LL_RESERVED_SPACE(dev));
	b = (struct bootp_pkt *) skb_put(skb, sizeof(struct bootp_pkt));
	memset(b, 0, sizeof(struct bootp_pkt));

	/* Construct IP header */
	skb_reset_network_header(skb);
	h = ip_hdr(skb);
	h->version = 4;
	h->ihl = 5;
	h->tot_len = htons(sizeof(struct bootp_pkt));
	h->frag_off = htons(IP_DF);
	h->ttl = 64;
	h->protocol = IPPROTO_UDP;
	h->daddr = htonl(INADDR_BROADCAST);
	h->check = ip_fast_csum((unsigned char *) h, h->ihl);

	/* Construct UDP header */
	b->udph.source = htons(68);
	b->udph.dest = htons(67);
	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */

	/* Construct DHCP/BOOTP header */
	b->op = BOOTP_REQUEST;
	if (dev->type < 256) /* check for false types */
		b->htype = dev->type;
	else if (dev->type == ARPHRD_IEEE802_TR) /* fix for token ring */
		b->htype = ARPHRD_IEEE802;
	else if (dev->type == ARPHRD_FDDI)
		b->htype = ARPHRD_ETHER;
	else {
		printk("Unknown ARP type 0x%04x for device %s\n", dev->type, dev->name);
		b->htype = dev->type; /* can cause undefined behavior */
	}

	/* server_ip and your_ip address are both already zero per RFC2131 */
	b->hlen = dev->addr_len;
	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
	b->secs = htons(jiffies_diff / HZ);
	b->xid = d->xid;

	/* add DHCP options or BOOTP extensions */
#ifdef IPCONFIG_DHCP
	if (ic_proto_enabled & IC_USE_DHCP)
		ic_dhcp_init_options(b->exten);
	else
#endif
		ic_bootp_init_ext(b->exten);

	/* Chain packet down the line... */
	skb->dev = dev;
	skb->protocol = htons(ETH_P_IP);
	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
			    dev->broadcast, dev->dev_addr, skb->len) < 0 ||
	    dev_queue_xmit(skb) < 0)
		printk("E");
}


/*
 *  Copy BOOTP-supplied string if not already set.
 */
static int __init ic_bootp_string(char *dest, char *src, int len, int max)
{
	if (!len)
		return 0;
	if (len > max-1)
		len = max-1;
	memcpy(dest, src, len);
	dest[len] = '\0';
	return 1;
}


/*
 *  Process BOOTP extensions.
 */
static void __init ic_do_bootp_ext(u8 *ext)
{
       u8 servers;
       int i;
	u16 mtu;

#ifdef IPCONFIG_DEBUG
	u8 *c;

	printk("DHCP/BOOTP: Got extension %d:",*ext);
	for (c=ext+2; c<ext+2+ext[1]; c++)
		printk(" %02x", *c);
	printk("\n");
#endif

	switch (*ext++) {
		case 1:		/* Subnet mask */
			if (ic_netmask == NONE)
				memcpy(&ic_netmask, ext+1, 4);
			break;
		case 3:		/* Default gateway */
			if (ic_gateway == NONE)
				memcpy(&ic_gateway, ext+1, 4);
			break;
		case 6:		/* DNS server */
			servers= *ext/4;
			if (servers > CONF_NAMESERVERS_MAX)
				servers = CONF_NAMESERVERS_MAX;
			for (i = 0; i < servers; i++) {
				if (ic_nameservers[i] == NONE)
					memcpy(&ic_nameservers[i], ext+1+4*i, 4);
			}
			break;
		case 12:	/* Host name */
			ic_bootp_string(utsname()->nodename, ext+1, *ext, __NEW_UTS_LEN);
			ic_host_name_set = 1;
			break;
		case 15:	/* Domain name (DNS) */
			ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
			break;
		case 17:	/* Root path */
			if (!root_server_path[0])
				ic_bootp_string(root_server_path, ext+1, *ext, sizeof(root_server_path));
			break;
		case 26:	/* Interface MTU */
			memcpy(&mtu, ext+1, sizeof(mtu));
			ic_dev_mtu = ntohs(mtu);
			break;
		case 40:	/* NIS Domain name (_not_ DNS) */
			ic_bootp_string(utsname()->domainname, ext+1, *ext, __NEW_UTS_LEN);
			break;
	}
}


/*
 *  Receive BOOTP reply.
 */
static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
{
	struct bootp_pkt *b;
	struct iphdr *h;
	struct ic_device *d;
	int len, ext_len;

	if (!net_eq(dev_net(dev), &init_net))
		goto drop;

	/* Perform verifications before taking the lock.  */
	if (skb->pkt_type == PACKET_OTHERHOST)
		goto drop;

	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
		return NET_RX_DROP;

	if (!pskb_may_pull(skb,
			   sizeof(struct iphdr) +
			   sizeof(struct udphdr)))
		goto drop;

	b = (struct bootp_pkt *)skb_network_header(skb);
	h = &b->iph;

	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
		goto drop;

	/* Fragments are not supported */
	if (h->frag_off & htons(IP_OFFSET | IP_MF)) {
		if (net_ratelimit())
			printk(KERN_ERR "DHCP/BOOTP: Ignoring fragmented "
			       "reply.\n");
		goto drop;
	}

	if (skb->len < ntohs(h->tot_len))
		goto drop;

	if (ip_fast_csum((char *) h, h->ihl))
		goto drop;

	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
		goto drop;

	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
		goto drop;

	len = ntohs(b->udph.len) - sizeof(struct udphdr);
	ext_len = len - (sizeof(*b) -
			 sizeof(struct iphdr) -
			 sizeof(struct udphdr) -
			 sizeof(b->exten));
	if (ext_len < 0)
		goto drop;

	/* Ok the front looks good, make sure we can get at the rest.  */
	if (!pskb_may_pull(skb, skb->len))
		goto drop;

	b = (struct bootp_pkt *)skb_network_header(skb);
	h = &b->iph;

	/* One reply at a time, please. */
	spin_lock(&ic_recv_lock);

	/* If we already have a reply, just drop the packet */
	if (ic_got_reply)
		goto drop_unlock;

	/* Find the ic_device that the packet arrived on */
	d = ic_first_dev;
	while (d && d->dev != dev)
		d = d->next;
	if (!d)
		goto drop_unlock;  /* should never happen */

	/* Is it a reply to our BOOTP request? */
	if (b->op != BOOTP_REPLY ||
	    b->xid != d->xid) {
		if (net_ratelimit())
			printk(KERN_ERR "DHCP/BOOTP: Reply not for us, "
			       "op[%x] xid[%x]\n",
			       b->op, b->xid);
		goto drop_unlock;
	}

	/* Is it a reply for the device we are configuring? */
	if (b->xid != ic_dev_xid) {
		if (net_ratelimit())
			printk(KERN_ERR "DHCP/BOOTP: Ignoring delayed packet\n");
		goto drop_unlock;
	}

	/* Parse extensions */
	if (ext_len >= 4 &&
	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
		u8 *ext;

#ifdef IPCONFIG_DHCP
		if (ic_proto_enabled & IC_USE_DHCP) {
			__be32 server_id = NONE;
			int mt = 0;

			ext = &b->exten[4];
			while (ext < end && *ext != 0xff) {
				u8 *opt = ext++;
				if (*opt == 0)	/* Padding */
					continue;
				ext += *ext + 1;
				if (ext >= end)
					break;
				switch (*opt) {
				case 53:	/* Message type */
					if (opt[1])
						mt = opt[2];
					break;
				case 54:	/* Server ID (IP address) */
					if (opt[1] >= 4)
						memcpy(&server_id, opt + 2, 4);
					break;
				}
			}

#ifdef IPCONFIG_DEBUG
			printk("DHCP: Got message type %d\n", mt);
#endif

			switch (mt) {
			case DHCPOFFER:
				/* While in the process of accepting one offer,
				 * ignore all others.
				 */
				if (ic_myaddr != NONE)
					goto drop_unlock;

				/* Let's accept that offer. */
				ic_myaddr = b->your_ip;
				ic_servaddr = server_id;
#ifdef IPCONFIG_DEBUG
				printk("DHCP: Offered address %pI4 by server %pI4\n",
				       &ic_myaddr, &ic_servaddr);
#endif
				/* The DHCP indicated server address takes
				 * precedence over the bootp header one if
				 * they are different.
				 */
				if ((server_id != NONE) &&
				    (b->server_ip != server_id))
					b->server_ip = ic_servaddr;
				break;

			case DHCPACK:
				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
					goto drop_unlock;

				/* Yeah! */
				break;

			default:
				/* Urque.  Forget it*/
				ic_myaddr = NONE;
				ic_servaddr = NONE;
				goto drop_unlock;
			}

			ic_dhcp_msgtype = mt;

		}
#endif /* IPCONFIG_DHCP */

		ext = &b->exten[4];
		while (ext < end && *ext != 0xff) {
			u8 *opt = ext++;
			if (*opt == 0)	/* Padding */
				continue;
			ext += *ext + 1;
			if (ext < end)
				ic_do_bootp_ext(opt);
		}
	}

	/* We have a winner! */
	ic_dev = dev;
	ic_myaddr = b->your_ip;
	ic_servaddr = b->server_ip;
	if (ic_gateway == NONE && b->relay_ip)
		ic_gateway = b->relay_ip;
	if (ic_nameservers[0] == NONE)
		ic_nameservers[0] = ic_servaddr;
	ic_got_reply = IC_BOOTP;

drop_unlock:
	/* Show's over.  Nothing to see here.  */
	spin_unlock(&ic_recv_lock);

drop:
	/* Throw the packet out. */
	kfree_skb(skb);

	return 0;
}


#endif


/*
 *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
 */

#ifdef IPCONFIG_DYNAMIC

static int __init ic_dynamic(void)
{
	int retries;
	struct ic_device *d;
	unsigned long start_jiffies, timeout, jiff;
	int do_bootp = ic_proto_have_if & IC_BOOTP;
	int do_rarp = ic_proto_have_if & IC_RARP;

	/*
	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
	 * This routine gets only called when some pieces of information
	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
	 */
	if (!ic_proto_enabled) {
		printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
		return -1;
	}

#ifdef IPCONFIG_BOOTP
	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
		printk(KERN_ERR "DHCP/BOOTP: No suitable device found.\n");
#endif
#ifdef IPCONFIG_RARP
	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
		printk(KERN_ERR "RARP: No suitable device found.\n");
#endif

	if (!ic_proto_have_if)
		/* Error message already printed */
		return -1;

	/*
	 * Setup protocols
	 */
#ifdef IPCONFIG_BOOTP
	if (do_bootp)
		ic_bootp_init();
#endif
#ifdef IPCONFIG_RARP
	if (do_rarp)
		ic_rarp_init();
#endif

	/*
	 * Send requests and wait, until we get an answer. This loop
	 * seems to be a terrible waste of CPU time, but actually there is
	 * only one process running at all, so we don't need to use any
	 * scheduler functions.
	 * [Actually we could now, but the nothing else running note still
	 *  applies.. - AC]
	 */
	printk(KERN_NOTICE "Sending %s%s%s requests .",
	       do_bootp
		? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
	       (do_bootp && do_rarp) ? " and " : "",
	       do_rarp ? "RARP" : "");

	start_jiffies = jiffies;
	d = ic_first_dev;
	retries = CONF_SEND_RETRIES;
	get_random_bytes(&timeout, sizeof(timeout));
	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned) CONF_TIMEOUT_RANDOM);
	for (;;) {
		/* Track the device we are configuring */
		ic_dev_xid = d->xid;

#ifdef IPCONFIG_BOOTP
		if (do_bootp && (d->able & IC_BOOTP))
			ic_bootp_send_if(d, jiffies - start_jiffies);
#endif
#ifdef IPCONFIG_RARP
		if (do_rarp && (d->able & IC_RARP))
			ic_rarp_send_if(d);
#endif

		jiff = jiffies + (d->next ? CONF_INTER_TIMEOUT : timeout);
		while (time_before(jiffies, jiff) && !ic_got_reply)
			schedule_timeout_uninterruptible(1);
#ifdef IPCONFIG_DHCP
		/* DHCP isn't done until we get a DHCPACK. */
		if ((ic_got_reply & IC_BOOTP) &&
		    (ic_proto_enabled & IC_USE_DHCP) &&
		    ic_dhcp_msgtype != DHCPACK) {
			ic_got_reply = 0;
			printk(",");
			continue;
		}
#endif /* IPCONFIG_DHCP */

		if (ic_got_reply) {
			printk(" OK\n");
			break;
		}

		if ((d = d->next))
			continue;

		if (! --retries) {
			printk(" timed out!\n");
			break;
		}

		d = ic_first_dev;

		timeout = timeout CONF_TIMEOUT_MULT;
		if (timeout > CONF_TIMEOUT_MAX)
			timeout = CONF_TIMEOUT_MAX;

		printk(".");
	}

#ifdef IPCONFIG_BOOTP
	if (do_bootp)
		ic_bootp_cleanup();
#endif
#ifdef IPCONFIG_RARP
	if (do_rarp)
		ic_rarp_cleanup();
#endif

	if (!ic_got_reply) {
		ic_myaddr = NONE;
		return -1;
	}

	printk("IP-Config: Got %s answer from %pI4, ",
		((ic_got_reply & IC_RARP) ? "RARP"
		 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
		&ic_servaddr);
	printk("my address is %pI4\n", &ic_myaddr);

	return 0;
}

#endif /* IPCONFIG_DYNAMIC */

#ifdef CONFIG_PROC_FS

static int pnp_seq_show(struct seq_file *seq, void *v)
{
	int i;

	if (ic_proto_used & IC_PROTO)
		seq_printf(seq, "#PROTO: %s\n",
			   (ic_proto_used & IC_RARP) ? "RARP"
			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
	else
		seq_puts(seq, "#MANUAL\n");

	if (ic_domain[0])
		seq_printf(seq,
			   "domain %s\n", ic_domain);
	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
		if (ic_nameservers[i] != NONE)
			seq_printf(seq, "nameserver %pI4\n",
				   &ic_nameservers[i]);
	}
	if (ic_servaddr != NONE)
		seq_printf(seq, "bootserver %pI4\n",
			   &ic_servaddr);
	return 0;
}

static int pnp_seq_open(struct inode *indoe, struct file *file)
{
	return single_open(file, pnp_seq_show, NULL);
}

static const struct file_operations pnp_seq_fops = {
	.owner		= THIS_MODULE,
	.open		= pnp_seq_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};
#endif /* CONFIG_PROC_FS */

/*
 *  Extract IP address from the parameter string if needed. Note that we
 *  need to have root_server_addr set _before_ IPConfig gets called as it
 *  can override it.
 */
__be32 __init root_nfs_parse_addr(char *name)
{
	__be32 addr;
	int octets = 0;
	char *cp, *cq;

	cp = cq = name;
	while (octets < 4) {
		while (*cp >= '0' && *cp <= '9')
			cp++;
		if (cp == cq || cp - cq > 3)
			break;
		if (*cp == '.' || octets == 3)
			octets++;
		if (octets < 4)
			cp++;
		cq = cp;
	}
	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
		if (*cp == ':')
			*cp++ = '\0';
		addr = in_aton(name);
		memmove(name, cp, strlen(cp) + 1);
	} else
		addr = NONE;

	return addr;
}

#define DEVICE_WAIT_MAX		12 /* 12 seconds */

static int __init wait_for_devices(void)
{
	int i;

	msleep(CONF_PRE_OPEN);
	for (i = 0; i < DEVICE_WAIT_MAX; i++) {
		struct net_device *dev;
		int found = 0;

		rtnl_lock();
		for_each_netdev(&init_net, dev) {
			if (ic_device_match(dev)) {
				found = 1;
				break;
			}
		}
		rtnl_unlock();
		if (found)
			return 0;
		ssleep(1);
	}
	return -ENODEV;
}

/*
 *	IP Autoconfig dispatcher.
 */

static int __init ip_auto_config(void)
{
	__be32 addr;
#ifdef IPCONFIG_DYNAMIC
	int retries = CONF_OPEN_RETRIES;
#endif
	int err;

#ifdef CONFIG_PROC_FS
	proc_net_fops_create(&init_net, "pnp", S_IRUGO, &pnp_seq_fops);
#endif /* CONFIG_PROC_FS */

	if (!ic_enable)
		return 0;

	DBG(("IP-Config: Entered.\n"));
#ifdef IPCONFIG_DYNAMIC
 try_try_again:
#endif
	/* Wait for devices to appear */
	err = wait_for_devices();
	if (err)
		return err;

	/* Setup all network devices */
	err = ic_open_devs();
	if (err)
		return err;

	/* Give drivers a chance to settle */
	ssleep(CONF_POST_OPEN);

	/*
	 * If the config information is insufficient (e.g., our IP address or
	 * IP address of the boot server is missing or we have multiple network
	 * interfaces and no default was set), use BOOTP or RARP to get the
	 * missing values.
	 */
	if (ic_myaddr == NONE ||
#ifdef CONFIG_ROOT_NFS
	    (root_server_addr == NONE &&
	     ic_servaddr == NONE &&
	     ROOT_DEV == Root_NFS) ||
#endif
	    ic_first_dev->next) {
#ifdef IPCONFIG_DYNAMIC
		if (ic_dynamic() < 0) {
			ic_close_devs();

			/*
			 * I don't know why, but sometimes the
			 * eepro100 driver (at least) gets upset and
			 * doesn't work the first time it's opened.
			 * But then if you close it and reopen it, it
			 * works just fine.  So we need to try that at
			 * least once before giving up.
			 *
			 * Also, if the root will be NFS-mounted, we
			 * have nowhere to go if DHCP fails.  So we
			 * just have to keep trying forever.
			 *
			 * 				-- Chip
			 */
#ifdef CONFIG_ROOT_NFS
			if (ROOT_DEV ==  Root_NFS) {
				printk(KERN_ERR
					"IP-Config: Retrying forever (NFS root)...\n");
				goto try_try_again;
			}
#endif

			if (--retries) {
				printk(KERN_ERR
				       "IP-Config: Reopening network devices...\n");
				goto try_try_again;
			}

			/* Oh, well.  At least we tried. */
			printk(KERN_ERR "IP-Config: Auto-configuration of network failed.\n");
			return -1;
		}
#else /* !DYNAMIC */
		printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
		ic_close_devs();
		return -1;
#endif /* IPCONFIG_DYNAMIC */
	} else {
		/* Device selected manually or only one device -> use it */
		ic_dev = ic_first_dev->dev;
	}

	addr = root_nfs_parse_addr(root_server_path);
	if (root_server_addr == NONE)
		root_server_addr = addr;

	/*
	 * Use defaults whereever applicable.
	 */
	if (ic_defaults() < 0)
		return -1;

	/*
	 * Close all network devices except the device we've
	 * autoconfigured and set up routes.
	 */
	ic_close_devs();
	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
		return -1;

	/*
	 * Record which protocol was actually used.
	 */
#ifdef IPCONFIG_DYNAMIC
	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
#endif

#ifndef IPCONFIG_SILENT
	/*
	 * Clue in the operator.
	 */
	printk("IP-Config: Complete:");
	printk("\n     device=%s", ic_dev->name);
	printk(", addr=%pI4", &ic_myaddr);
	printk(", mask=%pI4", &ic_netmask);
	printk(", gw=%pI4", &ic_gateway);
	printk(",\n     host=%s, domain=%s, nis-domain=%s",
	       utsname()->nodename, ic_domain, utsname()->domainname);
	printk(",\n     bootserver=%pI4", &ic_servaddr);
	printk(", rootserver=%pI4", &root_server_addr);
	printk(", rootpath=%s", root_server_path);
	if (ic_dev_mtu)
		printk(", mtu=%d", ic_dev_mtu);
	printk("\n");
#endif /* !SILENT */

	return 0;
}

late_initcall(ip_auto_config);


/*
 *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
 *  command line parameter.  See Documentation/filesystems/nfs/nfsroot.txt.
 */
static int __init ic_proto_name(char *name)
{
	if (!strcmp(name, "on") || !strcmp(name, "any")) {
		return 1;
	}
	if (!strcmp(name, "off") || !strcmp(name, "none")) {
		return 0;
	}
#ifdef CONFIG_IP_PNP_DHCP
	else if (!strcmp(name, "dhcp")) {
		ic_proto_enabled &= ~IC_RARP;
		return 1;
	}
#endif
#ifdef CONFIG_IP_PNP_BOOTP
	else if (!strcmp(name, "bootp")) {
		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
		return 1;
	}
#endif
#ifdef CONFIG_IP_PNP_RARP
	else if (!strcmp(name, "rarp")) {
		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
		return 1;
	}
#endif
#ifdef IPCONFIG_DYNAMIC
	else if (!strcmp(name, "both")) {
		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
		return 1;
	}
#endif
	return 0;
}

static int __init ip_auto_config_setup(char *addrs)
{
	char *cp, *ip, *dp;
	int num = 0;

	ic_set_manually = 1;
	ic_enable = 1;

	/*
	 * If any dhcp, bootp etc options are set, leave autoconfig on
	 * and skip the below static IP processing.
	 */
	if (ic_proto_name(addrs))
		return 1;

	/* If no static IP is given, turn off autoconfig and bail.  */
	if (*addrs == 0 ||
	    strcmp(addrs, "off") == 0 ||
	    strcmp(addrs, "none") == 0) {
		ic_enable = 0;
		return 1;
	}

	/* Parse string for static IP assignment.  */
	ip = addrs;
	while (ip && *ip) {
		if ((cp = strchr(ip, ':')))
			*cp++ = '\0';
		if (strlen(ip) > 0) {
			DBG(("IP-Config: Parameter #%d: `%s'\n", num, ip));
			switch (num) {
			case 0:
				if ((ic_myaddr = in_aton(ip)) == ANY)
					ic_myaddr = NONE;
				break;
			case 1:
				if ((ic_servaddr = in_aton(ip)) == ANY)
					ic_servaddr = NONE;
				break;
			case 2:
				if ((ic_gateway = in_aton(ip)) == ANY)
					ic_gateway = NONE;
				break;
			case 3:
				if ((ic_netmask = in_aton(ip)) == ANY)
					ic_netmask = NONE;
				break;
			case 4:
				if ((dp = strchr(ip, '.'))) {
					*dp++ = '\0';
					strlcpy(utsname()->domainname, dp,
						sizeof(utsname()->domainname));
				}
				strlcpy(utsname()->nodename, ip,
					sizeof(utsname()->nodename));
				ic_host_name_set = 1;
				break;
			case 5:
				strlcpy(user_dev_name, ip, sizeof(user_dev_name));
				break;
			case 6:
				if (ic_proto_name(ip) == 0 &&
				    ic_myaddr == NONE) {
					ic_enable = 0;
				}
				break;
			}
		}
		ip = cp;
		num++;
	}

	return 1;
}

static int __init nfsaddrs_config_setup(char *addrs)
{
	return ip_auto_config_setup(addrs);
}

static int __init vendor_class_identifier_setup(char *addrs)
{
	if (strlcpy(vendor_class_identifier, addrs,
		    sizeof(vendor_class_identifier))
	    >= sizeof(vendor_class_identifier))
		printk(KERN_WARNING "DHCP: vendorclass too long, truncated to \"%s\"",
		       vendor_class_identifier);
	return 1;
}

__setup("ip=", ip_auto_config_setup);
__setup("nfsaddrs=", nfsaddrs_config_setup);
__setup("dhcpclass=", vendor_class_identifier_setup);