1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or
   4 *  user-supplied information to configure own IP address and routes.
   5 *
   6 *  Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
   7 *
   8 *  Derived from network configuration code in fs/nfs/nfsroot.c,
   9 *  originally Copyright (C) 1995, 1996 Gero Kuhlmann and me.
  10 *
  11 *  BOOTP rewritten to construct and analyse packets itself instead
  12 *  of misusing the IP layer. num_bugs_causing_wrong_arp_replies--;
  13 *					     -- MJ, December 1998
  14 *
  15 *  Fixed ip_auto_config_setup calling at startup in the new "Linker Magic"
  16 *  initialization scheme.
  17 *	- Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999
  18 *
  19 *  DHCP support added.  To users this looks like a whole separate
  20 *  protocol, but we know it's just a bag on the side of BOOTP.
  21 *		-- Chip Salzenberg <chip@valinux.com>, May 2000
  22 *
  23 *  Ported DHCP support from 2.2.16 to 2.4.0-test4
  24 *              -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000
  25 *
  26 *  Merged changes from 2.2.19 into 2.4.3
  27 *              -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001
  28 *
  29 *  Multiple Nameservers in /proc/net/pnp
  30 *              --  Josef Siemes <jsiemes@web.de>, Aug 2002
  31 *
  32 *  NTP servers in /proc/net/ipconfig/ntp_servers
  33 *              --  Chris Novakovic <chris@chrisn.me.uk>, April 2018
  34 */
  35
  36#include <linux/types.h>
  37#include <linux/string.h>
  38#include <linux/kernel.h>
  39#include <linux/jiffies.h>
  40#include <linux/random.h>
  41#include <linux/init.h>
  42#include <linux/utsname.h>
  43#include <linux/in.h>
  44#include <linux/if.h>
  45#include <linux/inet.h>
  46#include <linux/inetdevice.h>
  47#include <linux/netdevice.h>
  48#include <linux/if_arp.h>
  49#include <linux/skbuff.h>
  50#include <linux/ip.h>
  51#include <linux/socket.h>
  52#include <linux/route.h>
  53#include <linux/udp.h>
  54#include <linux/proc_fs.h>
  55#include <linux/seq_file.h>
  56#include <linux/major.h>
  57#include <linux/root_dev.h>
  58#include <linux/delay.h>
  59#include <linux/nfs_fs.h>
  60#include <linux/slab.h>
  61#include <linux/export.h>
  62#include <net/net_namespace.h>
  63#include <net/arp.h>
  64#include <net/ip.h>
  65#include <net/ipconfig.h>
  66#include <net/route.h>
  67
  68#include <linux/uaccess.h>
  69#include <net/checksum.h>
  70#include <asm/processor.h>
  71
  72#if defined(CONFIG_IP_PNP_DHCP)
  73#define IPCONFIG_DHCP
  74#endif
  75#if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
  76#define IPCONFIG_BOOTP
  77#endif
  78#if defined(CONFIG_IP_PNP_RARP)
  79#define IPCONFIG_RARP
  80#endif
  81#if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
  82#define IPCONFIG_DYNAMIC
  83#endif
  84
  85/* Define the friendly delay before and after opening net devices */
  86#define CONF_POST_OPEN		10	/* After opening: 10 msecs */
  87
  88/* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
  89#define CONF_OPEN_RETRIES 	2	/* (Re)open devices twice */
  90#define CONF_SEND_RETRIES 	6	/* Send six requests per open */
  91#define CONF_BASE_TIMEOUT	(HZ*2)	/* Initial timeout: 2 seconds */
  92#define CONF_TIMEOUT_RANDOM	(HZ)	/* Maximum amount of randomization */
  93#define CONF_TIMEOUT_MULT	*7/4	/* Rate of timeout growth */
  94#define CONF_TIMEOUT_MAX	(HZ*30)	/* Maximum allowed timeout */
  95#define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
  96					   - '3' from resolv.h */
  97#define CONF_NTP_SERVERS_MAX   3	/* Maximum number of NTP servers */
  98
  99#define NONE cpu_to_be32(INADDR_NONE)
 100#define ANY cpu_to_be32(INADDR_ANY)
 101
 102/* Wait for carrier timeout default in seconds */
 103static unsigned int carrier_timeout = 120;
 104
 105/*
 106 * Public IP configuration
 107 */
 108
 109/* This is used by platforms which might be able to set the ipconfig
 110 * variables using firmware environment vars.  If this is set, it will
 111 * ignore such firmware variables.
 112 */
 113int ic_set_manually __initdata = 0;		/* IPconfig parameters set manually */
 114
 115static int ic_enable __initdata;		/* IP config enabled? */
 116
 117/* Protocol choice */
 118int ic_proto_enabled __initdata = 0
 119#ifdef IPCONFIG_BOOTP
 120			| IC_BOOTP
 121#endif
 122#ifdef CONFIG_IP_PNP_DHCP
 123			| IC_USE_DHCP
 124#endif
 125#ifdef IPCONFIG_RARP
 126			| IC_RARP
 127#endif
 128			;
 129
 130static int ic_host_name_set __initdata;	/* Host name set by us? */
 131
 132__be32 ic_myaddr = NONE;		/* My IP address */
 133static __be32 ic_netmask = NONE;	/* Netmask for local subnet */
 134__be32 ic_gateway = NONE;	/* Gateway IP address */
 135
 136#ifdef IPCONFIG_DYNAMIC
 137static __be32 ic_addrservaddr = NONE;	/* IP Address of the IP addresses'server */
 138#endif
 139
 140__be32 ic_servaddr = NONE;	/* Boot server IP address */
 141
 142__be32 root_server_addr = NONE;	/* Address of NFS server */
 143u8 root_server_path[256] = { 0, };	/* Path to mount as root */
 144
 145/* vendor class identifier */
 146static char vendor_class_identifier[253] __initdata;
 147
 148#if defined(CONFIG_IP_PNP_DHCP)
 149static char dhcp_client_identifier[253] __initdata;
 150#endif
 151
 152/* Persistent data: */
 153
 154#ifdef IPCONFIG_DYNAMIC
 155static int ic_proto_used;			/* Protocol used, if any */
 156#else
 157#define ic_proto_used 0
 158#endif
 159static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
 160static __be32 ic_ntp_servers[CONF_NTP_SERVERS_MAX]; /* NTP server IP addresses */
 161static u8 ic_domain[64];		/* DNS (not NIS) domain name */
 162
 163/*
 164 * Private state.
 165 */
 166
 167/* Name of user-selected boot device */
 168static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
 169
 170/* Protocols supported by available interfaces */
 171static int ic_proto_have_if __initdata;
 172
 173/* MTU for boot device */
 174static int ic_dev_mtu __initdata;
 175
 176#ifdef IPCONFIG_DYNAMIC
 177static DEFINE_SPINLOCK(ic_recv_lock);
 178static volatile int ic_got_reply __initdata;    /* Proto(s) that replied */
 179#endif
 180#ifdef IPCONFIG_DHCP
 181static int ic_dhcp_msgtype __initdata;	/* DHCP msg type received */
 182#endif
 183
 184
 185/*
 186 *	Network devices
 187 */
 188
 189struct ic_device {
 190	struct ic_device *next;
 191	struct net_device *dev;
 192	unsigned short flags;
 193	short able;
 194	__be32 xid;
 195};
 196
 197static struct ic_device *ic_first_dev __initdata;	/* List of open device */
 198static struct ic_device *ic_dev __initdata;		/* Selected device */
 199
 200static bool __init ic_is_init_dev(struct net_device *dev)
 201{
 202	if (dev->flags & IFF_LOOPBACK)
 203		return false;
 204	return user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
 205	    (!(dev->flags & IFF_LOOPBACK) &&
 206	     (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
 207	     strncmp(dev->name, "dummy", 5));
 208}
 209
 210static int __init ic_open_devs(void)
 211{
 212	struct ic_device *d, **last;
 213	struct net_device *dev;
 214	unsigned short oflags;
 215	unsigned long start, next_msg;
 216
 217	last = &ic_first_dev;
 218	rtnl_lock();
 219
 220	/* bring loopback device up first */
 221	for_each_netdev(&init_net, dev) {
 222		if (!(dev->flags & IFF_LOOPBACK))
 223			continue;
 224		if (dev_change_flags(dev, dev->flags | IFF_UP, NULL) < 0)
 225			pr_err("IP-Config: Failed to open %s\n", dev->name);
 226	}
 227
 228	for_each_netdev(&init_net, dev) {
 229		if (ic_is_init_dev(dev)) {
 230			int able = 0;
 231			if (dev->mtu >= 364)
 232				able |= IC_BOOTP;
 233			else
 234				pr_warn("DHCP/BOOTP: Ignoring device %s, MTU %d too small\n",
 235					dev->name, dev->mtu);
 236			if (!(dev->flags & IFF_NOARP))
 237				able |= IC_RARP;
 238			able &= ic_proto_enabled;
 239			if (ic_proto_enabled && !able)
 240				continue;
 241			oflags = dev->flags;
 242			if (dev_change_flags(dev, oflags | IFF_UP, NULL) < 0) {
 243				pr_err("IP-Config: Failed to open %s\n",
 244				       dev->name);
 245				continue;
 246			}
 247			if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
 248				rtnl_unlock();
 249				return -ENOMEM;
 250			}
 251			d->dev = dev;
 252			*last = d;
 253			last = &d->next;
 254			d->flags = oflags;
 255			d->able = able;
 256			if (able & IC_BOOTP)
 257				get_random_bytes(&d->xid, sizeof(__be32));
 258			else
 259				d->xid = 0;
 260			ic_proto_have_if |= able;
 261			pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n",
 262				 dev->name, able, d->xid);
 263		}
 264	}
 265	/* Devices with a complex topology like SFP ethernet interfaces needs
 266	 * the rtnl_lock at init. The carrier wait-loop must therefore run
 267	 * without holding it.
 268	 */
 269	rtnl_unlock();
 270
 271	/* no point in waiting if we could not bring up at least one device */
 272	if (!ic_first_dev)
 273		goto have_carrier;
 274
 275	/* wait for a carrier on at least one device */
 276	start = jiffies;
 277	next_msg = start + msecs_to_jiffies(20000);
 278	while (time_before(jiffies, start +
 279			   msecs_to_jiffies(carrier_timeout * 1000))) {
 280		int wait, elapsed;
 281
 282		rtnl_lock();
 283		for_each_netdev(&init_net, dev)
 284			if (ic_is_init_dev(dev) && netif_carrier_ok(dev)) {
 285				rtnl_unlock();
 286				goto have_carrier;
 287			}
 288		rtnl_unlock();
 289
 290		msleep(1);
 291
 292		if (time_before(jiffies, next_msg))
 293			continue;
 294
 295		elapsed = jiffies_to_msecs(jiffies - start);
 296		wait = (carrier_timeout * 1000 - elapsed + 500) / 1000;
 297		pr_info("Waiting up to %d more seconds for network.\n", wait);
 298		next_msg = jiffies + msecs_to_jiffies(20000);
 299	}
 300have_carrier:
 301
 302	*last = NULL;
 303
 304	if (!ic_first_dev) {
 305		if (user_dev_name[0])
 306			pr_err("IP-Config: Device `%s' not found\n",
 307			       user_dev_name);
 308		else
 309			pr_err("IP-Config: No network devices available\n");
 310		return -ENODEV;
 311	}
 312	return 0;
 313}
 314
 315/* Close all network interfaces except the one we've autoconfigured, and its
 316 * lowers, in case it's a stacked virtual interface.
 317 */
 318static void __init ic_close_devs(void)
 319{
 320	struct net_device *selected_dev = ic_dev ? ic_dev->dev : NULL;
 321	struct ic_device *d, *next;
 322	struct net_device *dev;
 323
 324	rtnl_lock();
 325	next = ic_first_dev;
 326	while ((d = next)) {
 327		bool bring_down = (d != ic_dev);
 328		struct net_device *lower;
 329		struct list_head *iter;
 330
 331		next = d->next;
 332		dev = d->dev;
 333
 334		if (selected_dev) {
 335			netdev_for_each_lower_dev(selected_dev, lower, iter) {
 336				if (dev == lower) {
 337					bring_down = false;
 338					break;
 339				}
 340			}
 341		}
 342		if (bring_down) {
 343			pr_debug("IP-Config: Downing %s\n", dev->name);
 344			dev_change_flags(dev, d->flags, NULL);
 345		}
 346		kfree(d);
 347	}
 348	rtnl_unlock();
 349}
 350
 351/*
 352 *	Interface to various network functions.
 353 */
 354
 355static inline void
 356set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
 357{
 358	sin->sin_family = AF_INET;
 359	sin->sin_addr.s_addr = addr;
 360	sin->sin_port = port;
 361}
 362
 363/*
 364 *	Set up interface addresses and routes.
 365 */
 366
 367static int __init ic_setup_if(void)
 368{
 369	struct ifreq ir;
 370	struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
 371	int err;
 372
 373	memset(&ir, 0, sizeof(ir));
 374	strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name);
 375	set_sockaddr(sin, ic_myaddr, 0);
 376	if ((err = devinet_ioctl(&init_net, SIOCSIFADDR, &ir)) < 0) {
 377		pr_err("IP-Config: Unable to set interface address (%d)\n",
 378		       err);
 379		return -1;
 380	}
 381	set_sockaddr(sin, ic_netmask, 0);
 382	if ((err = devinet_ioctl(&init_net, SIOCSIFNETMASK, &ir)) < 0) {
 383		pr_err("IP-Config: Unable to set interface netmask (%d)\n",
 384		       err);
 385		return -1;
 386	}
 387	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
 388	if ((err = devinet_ioctl(&init_net, SIOCSIFBRDADDR, &ir)) < 0) {
 389		pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
 390		       err);
 391		return -1;
 392	}
 393	/* Handle the case where we need non-standard MTU on the boot link (a network
 394	 * using jumbo frames, for instance).  If we can't set the mtu, don't error
 395	 * out, we'll try to muddle along.
 396	 */
 397	if (ic_dev_mtu != 0) {
 398		rtnl_lock();
 399		if ((err = dev_set_mtu(ic_dev->dev, ic_dev_mtu)) < 0)
 400			pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
 401			       ic_dev_mtu, err);
 402		rtnl_unlock();
 403	}
 404	return 0;
 405}
 406
 407static int __init ic_setup_routes(void)
 408{
 409	/* No need to setup device routes, only the default route... */
 410
 411	if (ic_gateway != NONE) {
 412		struct rtentry rm;
 413		int err;
 414
 415		memset(&rm, 0, sizeof(rm));
 416		if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
 417			pr_err("IP-Config: Gateway not on directly connected network\n");
 418			return -1;
 419		}
 420		set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
 421		set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
 422		set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
 423		rm.rt_flags = RTF_UP | RTF_GATEWAY;
 424		if ((err = ip_rt_ioctl(&init_net, SIOCADDRT, &rm)) < 0) {
 425			pr_err("IP-Config: Cannot add default route (%d)\n",
 426			       err);
 427			return -1;
 428		}
 429	}
 430
 431	return 0;
 432}
 433
 434/*
 435 *	Fill in default values for all missing parameters.
 436 */
 437
 438static int __init ic_defaults(void)
 439{
 440	/*
 441	 *	At this point we have no userspace running so need not
 442	 *	claim locks on system_utsname
 443	 */
 444
 445	if (!ic_host_name_set)
 446		sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
 447
 448	if (root_server_addr == NONE)
 449		root_server_addr = ic_servaddr;
 450
 451	if (ic_netmask == NONE) {
 452		if (IN_CLASSA(ntohl(ic_myaddr)))
 453			ic_netmask = htonl(IN_CLASSA_NET);
 454		else if (IN_CLASSB(ntohl(ic_myaddr)))
 455			ic_netmask = htonl(IN_CLASSB_NET);
 456		else if (IN_CLASSC(ntohl(ic_myaddr)))
 457			ic_netmask = htonl(IN_CLASSC_NET);
 458		else if (IN_CLASSE(ntohl(ic_myaddr)))
 459			ic_netmask = htonl(IN_CLASSE_NET);
 460		else {
 461			pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
 462			       &ic_myaddr);
 463			return -1;
 464		}
 465		pr_notice("IP-Config: Guessing netmask %pI4\n",
 466			  &ic_netmask);
 467	}
 468
 469	return 0;
 470}
 471
 472/*
 473 *	RARP support.
 474 */
 475
 476#ifdef IPCONFIG_RARP
 477
 478static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
 479
 480static struct packet_type rarp_packet_type __initdata = {
 481	.type =	cpu_to_be16(ETH_P_RARP),
 482	.func =	ic_rarp_recv,
 483};
 484
 485static inline void __init ic_rarp_init(void)
 486{
 487	dev_add_pack(&rarp_packet_type);
 488}
 489
 490static inline void __init ic_rarp_cleanup(void)
 491{
 492	dev_remove_pack(&rarp_packet_type);
 493}
 494
 495/*
 496 *  Process received RARP packet.
 497 */
 498static int __init
 499ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 500{
 501	struct arphdr *rarp;
 502	unsigned char *rarp_ptr;
 503	__be32 sip, tip;
 504	unsigned char *tha;		/* t for "target" */
 505	struct ic_device *d;
 506
 507	if (!net_eq(dev_net(dev), &init_net))
 508		goto drop;
 509
 510	skb = skb_share_check(skb, GFP_ATOMIC);
 511	if (!skb)
 512		return NET_RX_DROP;
 513
 514	if (!pskb_may_pull(skb, sizeof(struct arphdr)))
 515		goto drop;
 516
 517	/* Basic sanity checks can be done without the lock.  */
 518	rarp = (struct arphdr *)skb_transport_header(skb);
 519
 520	/* If this test doesn't pass, it's not IP, or we should
 521	 * ignore it anyway.
 522	 */
 523	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
 524		goto drop;
 525
 526	/* If it's not a RARP reply, delete it. */
 527	if (rarp->ar_op != htons(ARPOP_RREPLY))
 528		goto drop;
 529
 530	/* If it's not Ethernet, delete it. */
 531	if (rarp->ar_pro != htons(ETH_P_IP))
 532		goto drop;
 533
 534	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
 535		goto drop;
 536
 537	/* OK, it is all there and looks valid, process... */
 538	rarp = (struct arphdr *)skb_transport_header(skb);
 539	rarp_ptr = (unsigned char *) (rarp + 1);
 540
 541	/* One reply at a time, please. */
 542	spin_lock(&ic_recv_lock);
 543
 544	/* If we already have a reply, just drop the packet */
 545	if (ic_got_reply)
 546		goto drop_unlock;
 547
 548	/* Find the ic_device that the packet arrived on */
 549	d = ic_first_dev;
 550	while (d && d->dev != dev)
 551		d = d->next;
 552	if (!d)
 553		goto drop_unlock;	/* should never happen */
 554
 555	/* Extract variable-width fields */
 556	rarp_ptr += dev->addr_len;
 557	memcpy(&sip, rarp_ptr, 4);
 558	rarp_ptr += 4;
 559	tha = rarp_ptr;
 560	rarp_ptr += dev->addr_len;
 561	memcpy(&tip, rarp_ptr, 4);
 562
 563	/* Discard packets which are not meant for us. */
 564	if (memcmp(tha, dev->dev_addr, dev->addr_len))
 565		goto drop_unlock;
 566
 567	/* Discard packets which are not from specified server. */
 568	if (ic_servaddr != NONE && ic_servaddr != sip)
 569		goto drop_unlock;
 570
 571	/* We have a winner! */
 572	ic_dev = d;
 573	if (ic_myaddr == NONE)
 574		ic_myaddr = tip;
 575	ic_servaddr = sip;
 576	ic_addrservaddr = sip;
 577	ic_got_reply = IC_RARP;
 578
 579drop_unlock:
 580	/* Show's over.  Nothing to see here.  */
 581	spin_unlock(&ic_recv_lock);
 582
 583drop:
 584	/* Throw the packet out. */
 585	kfree_skb(skb);
 586	return 0;
 587}
 588
 589
 590/*
 591 *  Send RARP request packet over a single interface.
 592 */
 593static void __init ic_rarp_send_if(struct ic_device *d)
 594{
 595	struct net_device *dev = d->dev;
 596	arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
 597		 dev->dev_addr, dev->dev_addr);
 598}
 599#endif
 600
 601/*
 602 *  Predefine Nameservers
 603 */
 604static inline void __init ic_nameservers_predef(void)
 605{
 606	int i;
 607
 608	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
 609		ic_nameservers[i] = NONE;
 610}
 611
 612/* Predefine NTP servers */
 613static inline void __init ic_ntp_servers_predef(void)
 614{
 615	int i;
 616
 617	for (i = 0; i < CONF_NTP_SERVERS_MAX; i++)
 618		ic_ntp_servers[i] = NONE;
 619}
 620
 621/*
 622 *	DHCP/BOOTP support.
 623 */
 624
 625#ifdef IPCONFIG_BOOTP
 626
 627struct bootp_pkt {		/* BOOTP packet format */
 628	struct iphdr iph;	/* IP header */
 629	struct udphdr udph;	/* UDP header */
 630	u8 op;			/* 1=request, 2=reply */
 631	u8 htype;		/* HW address type */
 632	u8 hlen;		/* HW address length */
 633	u8 hops;		/* Used only by gateways */
 634	__be32 xid;		/* Transaction ID */
 635	__be16 secs;		/* Seconds since we started */
 636	__be16 flags;		/* Just what it says */
 637	__be32 client_ip;		/* Client's IP address if known */
 638	__be32 your_ip;		/* Assigned IP address */
 639	__be32 server_ip;		/* (Next, e.g. NFS) Server's IP address */
 640	__be32 relay_ip;		/* IP address of BOOTP relay */
 641	u8 hw_addr[16];		/* Client's HW address */
 642	u8 serv_name[64];	/* Server host name */
 643	u8 boot_file[128];	/* Name of boot file */
 644	u8 exten[312];		/* DHCP options / BOOTP vendor extensions */
 645};
 646
 647/* packet ops */
 648#define BOOTP_REQUEST	1
 649#define BOOTP_REPLY	2
 650
 651/* DHCP message types */
 652#define DHCPDISCOVER	1
 653#define DHCPOFFER	2
 654#define DHCPREQUEST	3
 655#define DHCPDECLINE	4
 656#define DHCPACK		5
 657#define DHCPNAK		6
 658#define DHCPRELEASE	7
 659#define DHCPINFORM	8
 660
 661static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
 662
 663static struct packet_type bootp_packet_type __initdata = {
 664	.type =	cpu_to_be16(ETH_P_IP),
 665	.func =	ic_bootp_recv,
 666};
 667
 668/* DHCPACK can overwrite DNS if fallback was set upon first BOOTP reply */
 669static int ic_nameservers_fallback __initdata;
 670
 671/*
 672 *  Initialize DHCP/BOOTP extension fields in the request.
 673 */
 674
 675static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
 676
 677#ifdef IPCONFIG_DHCP
 678
 679static void __init
 680ic_dhcp_init_options(u8 *options, struct ic_device *d)
 681{
 682	u8 mt = ((ic_servaddr == NONE)
 683		 ? DHCPDISCOVER : DHCPREQUEST);
 684	u8 *e = options;
 685	int len;
 686
 687	pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
 688
 689	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
 690	e += 4;
 691
 692	*e++ = 53;		/* DHCP message type */
 693	*e++ = 1;
 694	*e++ = mt;
 695
 696	if (mt == DHCPREQUEST) {
 697		*e++ = 54;	/* Server ID (IP address) */
 698		*e++ = 4;
 699		memcpy(e, &ic_servaddr, 4);
 700		e += 4;
 701
 702		*e++ = 50;	/* Requested IP address */
 703		*e++ = 4;
 704		memcpy(e, &ic_myaddr, 4);
 705		e += 4;
 706	}
 707
 708	/* always? */
 709	{
 710		static const u8 ic_req_params[] = {
 711			1,	/* Subnet mask */
 712			3,	/* Default gateway */
 713			6,	/* DNS server */
 714			12,	/* Host name */
 715			15,	/* Domain name */
 716			17,	/* Boot path */
 717			26,	/* MTU */
 718			40,	/* NIS domain name */
 719			42,	/* NTP servers */
 720		};
 721
 722		*e++ = 55;	/* Parameter request list */
 723		*e++ = sizeof(ic_req_params);
 724		memcpy(e, ic_req_params, sizeof(ic_req_params));
 725		e += sizeof(ic_req_params);
 726
 727		if (ic_host_name_set) {
 728			*e++ = 12;	/* host-name */
 729			len = strlen(utsname()->nodename);
 730			*e++ = len;
 731			memcpy(e, utsname()->nodename, len);
 732			e += len;
 733		}
 734		if (*vendor_class_identifier) {
 735			pr_info("DHCP: sending class identifier \"%s\"\n",
 736				vendor_class_identifier);
 737			*e++ = 60;	/* Class-identifier */
 738			len = strlen(vendor_class_identifier);
 739			*e++ = len;
 740			memcpy(e, vendor_class_identifier, len);
 741			e += len;
 742		}
 743		len = strlen(dhcp_client_identifier + 1);
 744		/* the minimum length of identifier is 2, include 1 byte type,
 745		 * and can not be larger than the length of options
 746		 */
 747		if (len >= 1 && len < 312 - (e - options) - 1) {
 748			*e++ = 61;
 749			*e++ = len + 1;
 750			memcpy(e, dhcp_client_identifier, len + 1);
 751			e += len + 1;
 752		}
 753	}
 754
 755	*e++ = 255;	/* End of the list */
 756}
 757
 758#endif /* IPCONFIG_DHCP */
 759
 760static void __init ic_bootp_init_ext(u8 *e)
 761{
 762	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
 763	e += 4;
 764	*e++ = 1;		/* Subnet mask request */
 765	*e++ = 4;
 766	e += 4;
 767	*e++ = 3;		/* Default gateway request */
 768	*e++ = 4;
 769	e += 4;
 770#if CONF_NAMESERVERS_MAX > 0
 771	*e++ = 6;		/* (DNS) name server request */
 772	*e++ = 4 * CONF_NAMESERVERS_MAX;
 773	e += 4 * CONF_NAMESERVERS_MAX;
 774#endif
 775	*e++ = 12;		/* Host name request */
 776	*e++ = 32;
 777	e += 32;
 778	*e++ = 40;		/* NIS Domain name request */
 779	*e++ = 32;
 780	e += 32;
 781	*e++ = 17;		/* Boot path */
 782	*e++ = 40;
 783	e += 40;
 784
 785	*e++ = 57;		/* set extension buffer size for reply */
 786	*e++ = 2;
 787	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
 788	*e++ = 150;
 789
 790	*e++ = 255;		/* End of the list */
 791}
 792
 793
 794/*
 795 *  Initialize the DHCP/BOOTP mechanism.
 796 */
 797static inline void __init ic_bootp_init(void)
 798{
 799	/* Re-initialise all name servers and NTP servers to NONE, in case any
 800	 * were set via the "ip=" or "nfsaddrs=" kernel command line parameters:
 801	 * any IP addresses specified there will already have been decoded but
 802	 * are no longer needed
 803	 */
 804	ic_nameservers_predef();
 805	ic_ntp_servers_predef();
 806
 807	dev_add_pack(&bootp_packet_type);
 808}
 809
 810
 811/*
 812 *  DHCP/BOOTP cleanup.
 813 */
 814static inline void __init ic_bootp_cleanup(void)
 815{
 816	dev_remove_pack(&bootp_packet_type);
 817}
 818
 819
 820/*
 821 *  Send DHCP/BOOTP request to single interface.
 822 */
 823static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
 824{
 825	struct net_device *dev = d->dev;
 826	struct sk_buff *skb;
 827	struct bootp_pkt *b;
 828	struct iphdr *h;
 829	int hlen = LL_RESERVED_SPACE(dev);
 830	int tlen = dev->needed_tailroom;
 831
 832	/* Allocate packet */
 833	skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
 834			GFP_KERNEL);
 835	if (!skb)
 836		return;
 837	skb_reserve(skb, hlen);
 838	b = skb_put_zero(skb, sizeof(struct bootp_pkt));
 839
 840	/* Construct IP header */
 841	skb_reset_network_header(skb);
 842	h = ip_hdr(skb);
 843	h->version = 4;
 844	h->ihl = 5;
 845	h->tot_len = htons(sizeof(struct bootp_pkt));
 846	h->frag_off = htons(IP_DF);
 847	h->ttl = 64;
 848	h->protocol = IPPROTO_UDP;
 849	h->daddr = htonl(INADDR_BROADCAST);
 850	h->check = ip_fast_csum((unsigned char *) h, h->ihl);
 851
 852	/* Construct UDP header */
 853	b->udph.source = htons(68);
 854	b->udph.dest = htons(67);
 855	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
 856	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
 857
 858	/* Construct DHCP/BOOTP header */
 859	b->op = BOOTP_REQUEST;
 860	if (dev->type < 256) /* check for false types */
 861		b->htype = dev->type;
 862	else if (dev->type == ARPHRD_FDDI)
 863		b->htype = ARPHRD_ETHER;
 864	else {
 865		pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
 866			dev->name);
 867		b->htype = dev->type; /* can cause undefined behavior */
 868	}
 869
 870	/* server_ip and your_ip address are both already zero per RFC2131 */
 871	b->hlen = dev->addr_len;
 872	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
 873	b->secs = htons(jiffies_diff / HZ);
 874	b->xid = d->xid;
 875
 876	/* add DHCP options or BOOTP extensions */
 877#ifdef IPCONFIG_DHCP
 878	if (ic_proto_enabled & IC_USE_DHCP)
 879		ic_dhcp_init_options(b->exten, d);
 880	else
 881#endif
 882		ic_bootp_init_ext(b->exten);
 883
 884	/* Chain packet down the line... */
 885	skb->dev = dev;
 886	skb->protocol = htons(ETH_P_IP);
 887	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
 888			    dev->broadcast, dev->dev_addr, skb->len) < 0) {
 889		kfree_skb(skb);
 890		printk("E");
 891		return;
 892	}
 893
 894	if (dev_queue_xmit(skb) < 0)
 895		printk("E");
 896}
 897
 898
 899/*
 900 *  Copy BOOTP-supplied string
 901 */
 902static int __init ic_bootp_string(char *dest, char *src, int len, int max)
 903{
 904	if (!len)
 905		return 0;
 906	if (len > max-1)
 907		len = max-1;
 908	memcpy(dest, src, len);
 909	dest[len] = '\0';
 910	return 1;
 911}
 912
 913
 914/*
 915 *  Process BOOTP extensions.
 916 */
 917static void __init ic_do_bootp_ext(u8 *ext)
 918{
 919	u8 servers;
 920	int i;
 921	__be16 mtu;
 922
 923	u8 *c;
 924
 925	pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
 926	for (c=ext+2; c<ext+2+ext[1]; c++)
 927		pr_debug(" %02x", *c);
 928	pr_debug("\n");
 929
 930	switch (*ext++) {
 931	case 1:		/* Subnet mask */
 932		if (ic_netmask == NONE)
 933			memcpy(&ic_netmask, ext+1, 4);
 934		break;
 935	case 3:		/* Default gateway */
 936		if (ic_gateway == NONE)
 937			memcpy(&ic_gateway, ext+1, 4);
 938		break;
 939	case 6:		/* DNS server */
 940		servers= *ext/4;
 941		if (servers > CONF_NAMESERVERS_MAX)
 942			servers = CONF_NAMESERVERS_MAX;
 943		for (i = 0; i < servers; i++) {
 944			if (ic_nameservers[i] == NONE ||
 945			    ic_nameservers_fallback)
 946				memcpy(&ic_nameservers[i], ext+1+4*i, 4);
 947		}
 948		break;
 949	case 12:	/* Host name */
 950		if (!ic_host_name_set) {
 951			ic_bootp_string(utsname()->nodename, ext+1, *ext,
 952					__NEW_UTS_LEN);
 953			ic_host_name_set = 1;
 954		}
 955		break;
 956	case 15:	/* Domain name (DNS) */
 957		if (!ic_domain[0])
 958			ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
 959		break;
 960	case 17:	/* Root path */
 961		if (!root_server_path[0])
 962			ic_bootp_string(root_server_path, ext+1, *ext,
 963					sizeof(root_server_path));
 964		break;
 965	case 26:	/* Interface MTU */
 966		memcpy(&mtu, ext+1, sizeof(mtu));
 967		ic_dev_mtu = ntohs(mtu);
 968		break;
 969	case 40:	/* NIS Domain name (_not_ DNS) */
 970		ic_bootp_string(utsname()->domainname, ext+1, *ext,
 971				__NEW_UTS_LEN);
 972		break;
 973	case 42:	/* NTP servers */
 974		servers = *ext / 4;
 975		if (servers > CONF_NTP_SERVERS_MAX)
 976			servers = CONF_NTP_SERVERS_MAX;
 977		for (i = 0; i < servers; i++) {
 978			if (ic_ntp_servers[i] == NONE)
 979				memcpy(&ic_ntp_servers[i], ext+1+4*i, 4);
 980		}
 981		break;
 982	}
 983}
 984
 985
 986/*
 987 *  Receive BOOTP reply.
 988 */
 989static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 990{
 991	struct bootp_pkt *b;
 992	struct iphdr *h;
 993	struct ic_device *d;
 994	int len, ext_len;
 995
 996	if (!net_eq(dev_net(dev), &init_net))
 997		goto drop;
 998
 999	/* Perform verifications before taking the lock.  */
1000	if (skb->pkt_type == PACKET_OTHERHOST)
1001		goto drop;
1002
1003	skb = skb_share_check(skb, GFP_ATOMIC);
1004	if (!skb)
1005		return NET_RX_DROP;
1006
1007	if (!pskb_may_pull(skb,
1008			   sizeof(struct iphdr) +
1009			   sizeof(struct udphdr)))
1010		goto drop;
1011
1012	b = (struct bootp_pkt *)skb_network_header(skb);
1013	h = &b->iph;
1014
1015	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
1016		goto drop;
1017
1018	/* Fragments are not supported */
1019	if (ip_is_fragment(h)) {
1020		net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
1021		goto drop;
1022	}
1023
1024	if (skb->len < ntohs(h->tot_len))
1025		goto drop;
1026
1027	if (ip_fast_csum((char *) h, h->ihl))
1028		goto drop;
1029
1030	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
1031		goto drop;
1032
1033	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
1034		goto drop;
1035
1036	len = ntohs(b->udph.len) - sizeof(struct udphdr);
1037	ext_len = len - (sizeof(*b) -
1038			 sizeof(struct iphdr) -
1039			 sizeof(struct udphdr) -
1040			 sizeof(b->exten));
1041	if (ext_len < 0)
1042		goto drop;
1043
1044	/* Ok the front looks good, make sure we can get at the rest.  */
1045	if (!pskb_may_pull(skb, skb->len))
1046		goto drop;
1047
1048	b = (struct bootp_pkt *)skb_network_header(skb);
1049	h = &b->iph;
1050
1051	/* One reply at a time, please. */
1052	spin_lock(&ic_recv_lock);
1053
1054	/* If we already have a reply, just drop the packet */
1055	if (ic_got_reply)
1056		goto drop_unlock;
1057
1058	/* Find the ic_device that the packet arrived on */
1059	d = ic_first_dev;
1060	while (d && d->dev != dev)
1061		d = d->next;
1062	if (!d)
1063		goto drop_unlock;  /* should never happen */
1064
1065	/* Is it a reply to our BOOTP request? */
1066	if (b->op != BOOTP_REPLY ||
1067	    b->xid != d->xid) {
1068		net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1069				    d->dev->name, b->op, b->xid);
1070		goto drop_unlock;
1071	}
1072
1073	/* Parse extensions */
1074	if (ext_len >= 4 &&
1075	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1076		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1077		u8 *ext;
1078
1079#ifdef IPCONFIG_DHCP
1080		if (ic_proto_enabled & IC_USE_DHCP) {
1081			__be32 server_id = NONE;
1082			int mt = 0;
1083
1084			ext = &b->exten[4];
1085			while (ext < end && *ext != 0xff) {
1086				u8 *opt = ext++;
1087				if (*opt == 0)	/* Padding */
1088					continue;
1089				ext += *ext + 1;
1090				if (ext >= end)
1091					break;
1092				switch (*opt) {
1093				case 53:	/* Message type */
1094					if (opt[1])
1095						mt = opt[2];
1096					break;
1097				case 54:	/* Server ID (IP address) */
1098					if (opt[1] >= 4)
1099						memcpy(&server_id, opt + 2, 4);
1100					break;
1101				}
1102			}
1103
1104			pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1105
1106			switch (mt) {
1107			case DHCPOFFER:
1108				/* While in the process of accepting one offer,
1109				 * ignore all others.
1110				 */
1111				if (ic_myaddr != NONE)
1112					goto drop_unlock;
1113
1114				/* Let's accept that offer. */
1115				ic_myaddr = b->your_ip;
1116				ic_servaddr = server_id;
1117				pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1118					 &ic_myaddr, &b->iph.saddr);
1119				/* The DHCP indicated server address takes
1120				 * precedence over the bootp header one if
1121				 * they are different.
1122				 */
1123				if ((server_id != NONE) &&
1124				    (b->server_ip != server_id))
1125					b->server_ip = ic_servaddr;
1126				break;
1127
1128			case DHCPACK:
1129				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1130					goto drop_unlock;
1131
1132				/* Yeah! */
1133				break;
1134
1135			default:
1136				/* Urque.  Forget it*/
1137				ic_myaddr = NONE;
1138				ic_servaddr = NONE;
1139				goto drop_unlock;
1140			}
1141
1142			ic_dhcp_msgtype = mt;
1143
1144		}
1145#endif /* IPCONFIG_DHCP */
1146
1147		ext = &b->exten[4];
1148		while (ext < end && *ext != 0xff) {
1149			u8 *opt = ext++;
1150			if (*opt == 0)	/* Padding */
1151				continue;
1152			ext += *ext + 1;
1153			if (ext < end)
1154				ic_do_bootp_ext(opt);
1155		}
1156	}
1157
1158	/* We have a winner! */
1159	ic_dev = d;
1160	ic_myaddr = b->your_ip;
1161	ic_servaddr = b->server_ip;
1162	ic_addrservaddr = b->iph.saddr;
1163	if (ic_gateway == NONE && b->relay_ip)
1164		ic_gateway = b->relay_ip;
1165	if (ic_nameservers[0] == NONE) {
1166		ic_nameservers[0] = ic_servaddr;
1167		ic_nameservers_fallback = 1;
1168	}
1169	ic_got_reply = IC_BOOTP;
1170
1171drop_unlock:
1172	/* Show's over.  Nothing to see here.  */
1173	spin_unlock(&ic_recv_lock);
1174
1175drop:
1176	/* Throw the packet out. */
1177	kfree_skb(skb);
1178
1179	return 0;
1180}
1181
1182
1183#endif
1184
1185
1186/*
1187 *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
1188 */
1189
1190#ifdef IPCONFIG_DYNAMIC
1191
1192static int __init ic_dynamic(void)
1193{
1194	int retries;
1195	struct ic_device *d;
1196	unsigned long start_jiffies, timeout, jiff;
1197	int do_bootp = ic_proto_have_if & IC_BOOTP;
1198	int do_rarp = ic_proto_have_if & IC_RARP;
1199
1200	/*
1201	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1202	 * This routine gets only called when some pieces of information
1203	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1204	 */
1205	if (!ic_proto_enabled) {
1206		pr_err("IP-Config: Incomplete network configuration information\n");
1207		return -1;
1208	}
1209
1210#ifdef IPCONFIG_BOOTP
1211	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1212		pr_err("DHCP/BOOTP: No suitable device found\n");
1213#endif
1214#ifdef IPCONFIG_RARP
1215	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1216		pr_err("RARP: No suitable device found\n");
1217#endif
1218
1219	if (!ic_proto_have_if)
1220		/* Error message already printed */
1221		return -1;
1222
1223	/*
1224	 * Setup protocols
1225	 */
1226#ifdef IPCONFIG_BOOTP
1227	if (do_bootp)
1228		ic_bootp_init();
1229#endif
1230#ifdef IPCONFIG_RARP
1231	if (do_rarp)
1232		ic_rarp_init();
1233#endif
1234
1235	/*
1236	 * Send requests and wait, until we get an answer. This loop
1237	 * seems to be a terrible waste of CPU time, but actually there is
1238	 * only one process running at all, so we don't need to use any
1239	 * scheduler functions.
1240	 * [Actually we could now, but the nothing else running note still
1241	 *  applies.. - AC]
1242	 */
1243	pr_notice("Sending %s%s%s requests .",
1244		  do_bootp
1245		  ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1246		  (do_bootp && do_rarp) ? " and " : "",
1247		  do_rarp ? "RARP" : "");
1248
1249	start_jiffies = jiffies;
1250	d = ic_first_dev;
1251	retries = CONF_SEND_RETRIES;
1252	get_random_bytes(&timeout, sizeof(timeout));
1253	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1254	for (;;) {
1255#ifdef IPCONFIG_BOOTP
1256		if (do_bootp && (d->able & IC_BOOTP))
1257			ic_bootp_send_if(d, jiffies - start_jiffies);
1258#endif
1259#ifdef IPCONFIG_RARP
1260		if (do_rarp && (d->able & IC_RARP))
1261			ic_rarp_send_if(d);
1262#endif
1263
1264		if (!d->next) {
1265			jiff = jiffies + timeout;
1266			while (time_before(jiffies, jiff) && !ic_got_reply)
1267				schedule_timeout_uninterruptible(1);
1268		}
1269#ifdef IPCONFIG_DHCP
1270		/* DHCP isn't done until we get a DHCPACK. */
1271		if ((ic_got_reply & IC_BOOTP) &&
1272		    (ic_proto_enabled & IC_USE_DHCP) &&
1273		    ic_dhcp_msgtype != DHCPACK) {
1274			ic_got_reply = 0;
1275			/* continue on device that got the reply */
1276			d = ic_dev;
1277			pr_cont(",");
1278			continue;
1279		}
1280#endif /* IPCONFIG_DHCP */
1281
1282		if (ic_got_reply) {
1283			pr_cont(" OK\n");
1284			break;
1285		}
1286
1287		if ((d = d->next))
1288			continue;
1289
1290		if (! --retries) {
1291			pr_cont(" timed out!\n");
1292			break;
1293		}
1294
1295		d = ic_first_dev;
1296
1297		timeout = timeout CONF_TIMEOUT_MULT;
1298		if (timeout > CONF_TIMEOUT_MAX)
1299			timeout = CONF_TIMEOUT_MAX;
1300
1301		pr_cont(".");
1302	}
1303
1304#ifdef IPCONFIG_BOOTP
1305	if (do_bootp)
1306		ic_bootp_cleanup();
1307#endif
1308#ifdef IPCONFIG_RARP
1309	if (do_rarp)
1310		ic_rarp_cleanup();
1311#endif
1312
1313	if (!ic_got_reply) {
1314		ic_myaddr = NONE;
1315		return -1;
1316	}
1317
1318	pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1319		((ic_got_reply & IC_RARP) ? "RARP"
1320		: (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1321		&ic_addrservaddr, &ic_myaddr);
1322
1323	return 0;
1324}
1325
1326#endif /* IPCONFIG_DYNAMIC */
1327
1328#ifdef CONFIG_PROC_FS
1329/* proc_dir_entry for /proc/net/ipconfig */
1330static struct proc_dir_entry *ipconfig_dir;
1331
1332/* Name servers: */
1333static int pnp_seq_show(struct seq_file *seq, void *v)
1334{
1335	int i;
1336
1337	if (ic_proto_used & IC_PROTO)
1338		seq_printf(seq, "#PROTO: %s\n",
1339			   (ic_proto_used & IC_RARP) ? "RARP"
1340			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1341	else
1342		seq_puts(seq, "#MANUAL\n");
1343
1344	if (ic_domain[0])
1345		seq_printf(seq,
1346			   "domain %s\n", ic_domain);
1347	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1348		if (ic_nameservers[i] != NONE)
1349			seq_printf(seq, "nameserver %pI4\n",
1350				   &ic_nameservers[i]);
1351	}
1352	if (ic_servaddr != NONE)
1353		seq_printf(seq, "bootserver %pI4\n",
1354			   &ic_servaddr);
1355	return 0;
1356}
1357
1358/* Create the /proc/net/ipconfig directory */
1359static int __init ipconfig_proc_net_init(void)
1360{
1361	ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net);
1362	if (!ipconfig_dir)
1363		return -ENOMEM;
1364
1365	return 0;
1366}
1367
1368/* Create a new file under /proc/net/ipconfig */
1369static int ipconfig_proc_net_create(const char *name,
1370				    const struct proc_ops *proc_ops)
1371{
1372	char *pname;
1373	struct proc_dir_entry *p;
1374
1375	if (!ipconfig_dir)
1376		return -ENOMEM;
1377
1378	pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name);
1379	if (!pname)
1380		return -ENOMEM;
1381
1382	p = proc_create(pname, 0444, init_net.proc_net, proc_ops);
1383	kfree(pname);
1384	if (!p)
1385		return -ENOMEM;
1386
1387	return 0;
1388}
1389
1390/* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */
1391static int ntp_servers_show(struct seq_file *seq, void *v)
1392{
1393	int i;
1394
1395	for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1396		if (ic_ntp_servers[i] != NONE)
1397			seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]);
1398	}
1399	return 0;
1400}
1401DEFINE_PROC_SHOW_ATTRIBUTE(ntp_servers);
1402#endif /* CONFIG_PROC_FS */
1403
1404/*
1405 *  Extract IP address from the parameter string if needed. Note that we
1406 *  need to have root_server_addr set _before_ IPConfig gets called as it
1407 *  can override it.
1408 */
1409__be32 __init root_nfs_parse_addr(char *name)
1410{
1411	__be32 addr;
1412	int octets = 0;
1413	char *cp, *cq;
1414
1415	cp = cq = name;
1416	while (octets < 4) {
1417		while (*cp >= '0' && *cp <= '9')
1418			cp++;
1419		if (cp == cq || cp - cq > 3)
1420			break;
1421		if (*cp == '.' || octets == 3)
1422			octets++;
1423		if (octets < 4)
1424			cp++;
1425		cq = cp;
1426	}
1427	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1428		if (*cp == ':')
1429			*cp++ = '\0';
1430		addr = in_aton(name);
1431		memmove(name, cp, strlen(cp) + 1);
1432	} else
1433		addr = NONE;
1434
1435	return addr;
1436}
1437
1438#define DEVICE_WAIT_MAX		12 /* 12 seconds */
1439
1440static int __init wait_for_devices(void)
1441{
1442	int i;
1443	bool try_init_devs = true;
1444
1445	for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1446		struct net_device *dev;
1447		int found = 0;
1448
1449		/* make sure deferred device probes are finished */
1450		wait_for_device_probe();
1451
1452		rtnl_lock();
1453		for_each_netdev(&init_net, dev) {
1454			if (ic_is_init_dev(dev)) {
1455				found = 1;
1456				break;
1457			}
1458		}
1459		rtnl_unlock();
1460		if (found)
1461			return 0;
1462		if (try_init_devs &&
1463		    (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) {
1464			try_init_devs = false;
1465			wait_for_init_devices_probe();
1466		}
1467		ssleep(1);
1468	}
1469	return -ENODEV;
1470}
1471
1472/*
1473 *	IP Autoconfig dispatcher.
1474 */
1475
1476static int __init ip_auto_config(void)
1477{
1478	__be32 addr;
1479#ifdef IPCONFIG_DYNAMIC
1480	int retries = CONF_OPEN_RETRIES;
1481#endif
1482	int err;
1483	unsigned int i, count;
1484
1485	/* Initialise all name servers and NTP servers to NONE (but only if the
1486	 * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded,
1487	 * otherwise we'll overwrite the IP addresses specified there)
1488	 */
1489	if (ic_set_manually == 0) {
1490		ic_nameservers_predef();
1491		ic_ntp_servers_predef();
1492	}
1493
1494#ifdef CONFIG_PROC_FS
1495	proc_create_single("pnp", 0444, init_net.proc_net, pnp_seq_show);
1496
1497	if (ipconfig_proc_net_init() == 0)
1498		ipconfig_proc_net_create("ntp_servers", &ntp_servers_proc_ops);
1499#endif /* CONFIG_PROC_FS */
1500
1501	if (!ic_enable)
1502		return 0;
1503
1504	pr_debug("IP-Config: Entered.\n");
1505#ifdef IPCONFIG_DYNAMIC
1506 try_try_again:
1507#endif
1508	/* Wait for devices to appear */
1509	err = wait_for_devices();
1510	if (err)
1511		return err;
1512
1513	/* Setup all network devices */
1514	err = ic_open_devs();
1515	if (err)
1516		return err;
1517
1518	/* Give drivers a chance to settle */
1519	msleep(CONF_POST_OPEN);
1520
1521	/*
1522	 * If the config information is insufficient (e.g., our IP address or
1523	 * IP address of the boot server is missing or we have multiple network
1524	 * interfaces and no default was set), use BOOTP or RARP to get the
1525	 * missing values.
1526	 */
1527	if (ic_myaddr == NONE ||
1528#if defined(CONFIG_ROOT_NFS) || defined(CONFIG_CIFS_ROOT)
1529	    (root_server_addr == NONE &&
1530	     ic_servaddr == NONE &&
1531	     (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) ||
1532#endif
1533	    ic_first_dev->next) {
1534#ifdef IPCONFIG_DYNAMIC
1535		if (ic_dynamic() < 0) {
1536			ic_close_devs();
1537
1538			/*
1539			 * I don't know why, but sometimes the
1540			 * eepro100 driver (at least) gets upset and
1541			 * doesn't work the first time it's opened.
1542			 * But then if you close it and reopen it, it
1543			 * works just fine.  So we need to try that at
1544			 * least once before giving up.
1545			 *
1546			 * Also, if the root will be NFS-mounted, we
1547			 * have nowhere to go if DHCP fails.  So we
1548			 * just have to keep trying forever.
1549			 *
1550			 * 				-- Chip
1551			 */
1552#ifdef CONFIG_ROOT_NFS
1553			if (ROOT_DEV ==  Root_NFS) {
1554				pr_err("IP-Config: Retrying forever (NFS root)...\n");
1555				goto try_try_again;
1556			}
1557#endif
1558#ifdef CONFIG_CIFS_ROOT
1559			if (ROOT_DEV == Root_CIFS) {
1560				pr_err("IP-Config: Retrying forever (CIFS root)...\n");
1561				goto try_try_again;
1562			}
1563#endif
1564
1565			if (--retries) {
1566				pr_err("IP-Config: Reopening network devices...\n");
1567				goto try_try_again;
1568			}
1569
1570			/* Oh, well.  At least we tried. */
1571			pr_err("IP-Config: Auto-configuration of network failed\n");
1572			return -1;
1573		}
1574#else /* !DYNAMIC */
1575		pr_err("IP-Config: Incomplete network configuration information\n");
1576		ic_close_devs();
1577		return -1;
1578#endif /* IPCONFIG_DYNAMIC */
1579	} else {
1580		/* Device selected manually or only one device -> use it */
1581		ic_dev = ic_first_dev;
1582	}
1583
1584	addr = root_nfs_parse_addr(root_server_path);
1585	if (root_server_addr == NONE)
1586		root_server_addr = addr;
1587
1588	/*
1589	 * Use defaults wherever applicable.
1590	 */
1591	if (ic_defaults() < 0)
1592		return -1;
1593
1594	/*
1595	 * Record which protocol was actually used.
1596	 */
1597#ifdef IPCONFIG_DYNAMIC
1598	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1599#endif
1600
1601#ifndef IPCONFIG_SILENT
1602	/*
1603	 * Clue in the operator.
1604	 */
1605	pr_info("IP-Config: Complete:\n");
1606
1607	pr_info("     device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1608		ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1609		&ic_myaddr, &ic_netmask, &ic_gateway);
1610	pr_info("     host=%s, domain=%s, nis-domain=%s\n",
1611		utsname()->nodename, ic_domain, utsname()->domainname);
1612	pr_info("     bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1613		&ic_servaddr, &root_server_addr, root_server_path);
1614	if (ic_dev_mtu)
1615		pr_cont(", mtu=%d", ic_dev_mtu);
1616	/* Name servers (if any): */
1617	for (i = 0, count = 0; i < CONF_NAMESERVERS_MAX; i++) {
1618		if (ic_nameservers[i] != NONE) {
1619			if (i == 0)
1620				pr_info("     nameserver%u=%pI4",
1621					i, &ic_nameservers[i]);
1622			else
1623				pr_cont(", nameserver%u=%pI4",
1624					i, &ic_nameservers[i]);
1625
1626			count++;
1627		}
1628		if ((i + 1 == CONF_NAMESERVERS_MAX) && count > 0)
1629			pr_cont("\n");
1630	}
1631	/* NTP servers (if any): */
1632	for (i = 0, count = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1633		if (ic_ntp_servers[i] != NONE) {
1634			if (i == 0)
1635				pr_info("     ntpserver%u=%pI4",
1636					i, &ic_ntp_servers[i]);
1637			else
1638				pr_cont(", ntpserver%u=%pI4",
1639					i, &ic_ntp_servers[i]);
1640
1641			count++;
1642		}
1643		if ((i + 1 == CONF_NTP_SERVERS_MAX) && count > 0)
1644			pr_cont("\n");
1645	}
1646#endif /* !SILENT */
1647
1648	/*
1649	 * Close all network devices except the device we've
1650	 * autoconfigured and set up routes.
1651	 */
1652	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1653		err = -1;
1654	else
1655		err = 0;
1656
1657	ic_close_devs();
1658
1659	return err;
1660}
1661
1662late_initcall(ip_auto_config);
1663
1664
1665/*
1666 *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1667 *  command line parameter.  See Documentation/admin-guide/nfs/nfsroot.rst.
1668 */
1669static int __init ic_proto_name(char *name)
1670{
1671	if (!strcmp(name, "on") || !strcmp(name, "any")) {
1672		return 1;
1673	}
1674	if (!strcmp(name, "off") || !strcmp(name, "none")) {
1675		return 0;
1676	}
1677#ifdef CONFIG_IP_PNP_DHCP
1678	else if (!strncmp(name, "dhcp", 4)) {
1679		char *client_id;
1680
1681		ic_proto_enabled &= ~IC_RARP;
1682		client_id = strstr(name, "dhcp,");
1683		if (client_id) {
1684			char *v;
1685
1686			client_id = client_id + 5;
1687			v = strchr(client_id, ',');
1688			if (!v)
1689				return 1;
1690			*v = 0;
1691			if (kstrtou8(client_id, 0, dhcp_client_identifier))
1692				pr_debug("DHCP: Invalid client identifier type\n");
1693			strncpy(dhcp_client_identifier + 1, v + 1, 251);
1694			*v = ',';
1695		}
1696		return 1;
1697	}
1698#endif
1699#ifdef CONFIG_IP_PNP_BOOTP
1700	else if (!strcmp(name, "bootp")) {
1701		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1702		return 1;
1703	}
1704#endif
1705#ifdef CONFIG_IP_PNP_RARP
1706	else if (!strcmp(name, "rarp")) {
1707		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1708		return 1;
1709	}
1710#endif
1711#ifdef IPCONFIG_DYNAMIC
1712	else if (!strcmp(name, "both")) {
1713		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1714		return 1;
1715	}
1716#endif
1717	return 0;
1718}
1719
1720static int __init ip_auto_config_setup(char *addrs)
1721{
1722	char *cp, *ip, *dp;
1723	int num = 0;
1724
1725	ic_set_manually = 1;
1726	ic_enable = 1;
1727
1728	/*
1729	 * If any dhcp, bootp etc options are set, leave autoconfig on
1730	 * and skip the below static IP processing.
1731	 */
1732	if (ic_proto_name(addrs))
1733		return 1;
1734
1735	/* If no static IP is given, turn off autoconfig and bail.  */
1736	if (*addrs == 0 ||
1737	    strcmp(addrs, "off") == 0 ||
1738	    strcmp(addrs, "none") == 0) {
1739		ic_enable = 0;
1740		return 1;
1741	}
1742
1743	/* Initialise all name servers and NTP servers to NONE */
1744	ic_nameservers_predef();
1745	ic_ntp_servers_predef();
1746
1747	/* Parse string for static IP assignment.  */
1748	ip = addrs;
1749	while (ip && *ip) {
1750		if ((cp = strchr(ip, ':')))
1751			*cp++ = '\0';
1752		if (strlen(ip) > 0) {
1753			pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1754			switch (num) {
1755			case 0:
1756				if ((ic_myaddr = in_aton(ip)) == ANY)
1757					ic_myaddr = NONE;
1758				break;
1759			case 1:
1760				if ((ic_servaddr = in_aton(ip)) == ANY)
1761					ic_servaddr = NONE;
1762				break;
1763			case 2:
1764				if ((ic_gateway = in_aton(ip)) == ANY)
1765					ic_gateway = NONE;
1766				break;
1767			case 3:
1768				if ((ic_netmask = in_aton(ip)) == ANY)
1769					ic_netmask = NONE;
1770				break;
1771			case 4:
1772				if ((dp = strchr(ip, '.'))) {
1773					*dp++ = '\0';
1774					strscpy(utsname()->domainname, dp,
1775						sizeof(utsname()->domainname));
1776				}
1777				strscpy(utsname()->nodename, ip,
1778					sizeof(utsname()->nodename));
1779				ic_host_name_set = 1;
1780				break;
1781			case 5:
1782				strscpy(user_dev_name, ip, sizeof(user_dev_name));
1783				break;
1784			case 6:
1785				if (ic_proto_name(ip) == 0 &&
1786				    ic_myaddr == NONE) {
1787					ic_enable = 0;
1788				}
1789				break;
1790			case 7:
1791				if (CONF_NAMESERVERS_MAX >= 1) {
1792					ic_nameservers[0] = in_aton(ip);
1793					if (ic_nameservers[0] == ANY)
1794						ic_nameservers[0] = NONE;
1795				}
1796				break;
1797			case 8:
1798				if (CONF_NAMESERVERS_MAX >= 2) {
1799					ic_nameservers[1] = in_aton(ip);
1800					if (ic_nameservers[1] == ANY)
1801						ic_nameservers[1] = NONE;
1802				}
1803				break;
1804			case 9:
1805				if (CONF_NTP_SERVERS_MAX >= 1) {
1806					ic_ntp_servers[0] = in_aton(ip);
1807					if (ic_ntp_servers[0] == ANY)
1808						ic_ntp_servers[0] = NONE;
1809				}
1810				break;
1811			}
1812		}
1813		ip = cp;
1814		num++;
1815	}
1816
1817	return 1;
1818}
1819__setup("ip=", ip_auto_config_setup);
1820
1821static int __init nfsaddrs_config_setup(char *addrs)
1822{
1823	return ip_auto_config_setup(addrs);
1824}
1825__setup("nfsaddrs=", nfsaddrs_config_setup);
1826
1827static int __init vendor_class_identifier_setup(char *addrs)
1828{
1829	if (strscpy(vendor_class_identifier, addrs,
1830		    sizeof(vendor_class_identifier))
1831	    >= sizeof(vendor_class_identifier))
1832		pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1833			vendor_class_identifier);
1834	return 1;
1835}
1836__setup("dhcpclass=", vendor_class_identifier_setup);
1837
1838static int __init set_carrier_timeout(char *str)
1839{
1840	ssize_t ret;
1841
1842	if (!str)
1843		return 0;
1844
1845	ret = kstrtouint(str, 0, &carrier_timeout);
1846	if (ret)
1847		return 0;
1848
1849	return 1;
1850}
1851__setup("carrier_timeout=", set_carrier_timeout);