xref: /linux/net/ipv4/ipconfig.c (revision 7505576d1c1ac0cfe85fdf90999433dd8b673012)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or
4  *  user-supplied information to configure own IP address and routes.
5  *
6  *  Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
7  *
8  *  Derived from network configuration code in fs/nfs/nfsroot.c,
9  *  originally Copyright (C) 1995, 1996 Gero Kuhlmann and me.
10  *
11  *  BOOTP rewritten to construct and analyse packets itself instead
12  *  of misusing the IP layer. num_bugs_causing_wrong_arp_replies--;
13  *					     -- MJ, December 1998
14  *
15  *  Fixed ip_auto_config_setup calling at startup in the new "Linker Magic"
16  *  initialization scheme.
17  *	- Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999
18  *
19  *  DHCP support added.  To users this looks like a whole separate
20  *  protocol, but we know it's just a bag on the side of BOOTP.
21  *		-- Chip Salzenberg <chip@valinux.com>, May 2000
22  *
23  *  Ported DHCP support from 2.2.16 to 2.4.0-test4
24  *              -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000
25  *
26  *  Merged changes from 2.2.19 into 2.4.3
27  *              -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001
28  *
29  *  Multiple Nameservers in /proc/net/pnp
30  *              --  Josef Siemes <jsiemes@web.de>, Aug 2002
31  *
32  *  NTP servers in /proc/net/ipconfig/ntp_servers
33  *              --  Chris Novakovic <chris@chrisn.me.uk>, April 2018
34  */
35 
36 #include <linux/types.h>
37 #include <linux/string.h>
38 #include <linux/kernel.h>
39 #include <linux/jiffies.h>
40 #include <linux/random.h>
41 #include <linux/init.h>
42 #include <linux/utsname.h>
43 #include <linux/in.h>
44 #include <linux/if.h>
45 #include <linux/inet.h>
46 #include <linux/inetdevice.h>
47 #include <linux/netdevice.h>
48 #include <linux/if_arp.h>
49 #include <linux/skbuff.h>
50 #include <linux/ip.h>
51 #include <linux/socket.h>
52 #include <linux/route.h>
53 #include <linux/udp.h>
54 #include <linux/proc_fs.h>
55 #include <linux/seq_file.h>
56 #include <linux/major.h>
57 #include <linux/root_dev.h>
58 #include <linux/delay.h>
59 #include <linux/nfs_fs.h>
60 #include <linux/slab.h>
61 #include <linux/export.h>
62 #include <net/net_namespace.h>
63 #include <net/arp.h>
64 #include <net/dsa.h>
65 #include <net/ip.h>
66 #include <net/ipconfig.h>
67 #include <net/route.h>
68 
69 #include <linux/uaccess.h>
70 #include <net/checksum.h>
71 #include <asm/processor.h>
72 
73 #if defined(CONFIG_IP_PNP_DHCP)
74 #define IPCONFIG_DHCP
75 #endif
76 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
77 #define IPCONFIG_BOOTP
78 #endif
79 #if defined(CONFIG_IP_PNP_RARP)
80 #define IPCONFIG_RARP
81 #endif
82 #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
83 #define IPCONFIG_DYNAMIC
84 #endif
85 
86 /* Define the friendly delay before and after opening net devices */
87 #define CONF_POST_OPEN		10	/* After opening: 10 msecs */
88 
89 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
90 #define CONF_OPEN_RETRIES 	2	/* (Re)open devices twice */
91 #define CONF_SEND_RETRIES 	6	/* Send six requests per open */
92 #define CONF_BASE_TIMEOUT	(HZ*2)	/* Initial timeout: 2 seconds */
93 #define CONF_TIMEOUT_RANDOM	(HZ)	/* Maximum amount of randomization */
94 #define CONF_TIMEOUT_MULT	*7/4	/* Rate of timeout growth */
95 #define CONF_TIMEOUT_MAX	(HZ*30)	/* Maximum allowed timeout */
96 #define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
97 					   - '3' from resolv.h */
98 #define CONF_NTP_SERVERS_MAX   3	/* Maximum number of NTP servers */
99 
100 #define NONE cpu_to_be32(INADDR_NONE)
101 #define ANY cpu_to_be32(INADDR_ANY)
102 
103 /* Wait for carrier timeout default in seconds */
104 static unsigned int carrier_timeout = 120;
105 
106 /*
107  * Public IP configuration
108  */
109 
110 /* This is used by platforms which might be able to set the ipconfig
111  * variables using firmware environment vars.  If this is set, it will
112  * ignore such firmware variables.
113  */
114 int ic_set_manually __initdata = 0;		/* IPconfig parameters set manually */
115 
116 static int ic_enable __initdata;		/* IP config enabled? */
117 
118 /* Protocol choice */
119 int ic_proto_enabled __initdata = 0
120 #ifdef IPCONFIG_BOOTP
121 			| IC_BOOTP
122 #endif
123 #ifdef CONFIG_IP_PNP_DHCP
124 			| IC_USE_DHCP
125 #endif
126 #ifdef IPCONFIG_RARP
127 			| IC_RARP
128 #endif
129 			;
130 
131 static int ic_host_name_set __initdata;	/* Host name set by us? */
132 
133 __be32 ic_myaddr = NONE;		/* My IP address */
134 static __be32 ic_netmask = NONE;	/* Netmask for local subnet */
135 __be32 ic_gateway = NONE;	/* Gateway IP address */
136 
137 #ifdef IPCONFIG_DYNAMIC
138 static __be32 ic_addrservaddr = NONE;	/* IP Address of the IP addresses'server */
139 #endif
140 
141 __be32 ic_servaddr = NONE;	/* Boot server IP address */
142 
143 __be32 root_server_addr = NONE;	/* Address of NFS server */
144 u8 root_server_path[256] = { 0, };	/* Path to mount as root */
145 
146 /* vendor class identifier */
147 static char vendor_class_identifier[253] __initdata;
148 
149 #if defined(CONFIG_IP_PNP_DHCP)
150 static char dhcp_client_identifier[253] __initdata;
151 #endif
152 
153 /* Persistent data: */
154 
155 #ifdef IPCONFIG_DYNAMIC
156 static int ic_proto_used;			/* Protocol used, if any */
157 #else
158 #define ic_proto_used 0
159 #endif
160 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
161 static __be32 ic_ntp_servers[CONF_NTP_SERVERS_MAX]; /* NTP server IP addresses */
162 static u8 ic_domain[64];		/* DNS (not NIS) domain name */
163 
164 /*
165  * Private state.
166  */
167 
168 /* Name of user-selected boot device */
169 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
170 
171 /* Protocols supported by available interfaces */
172 static int ic_proto_have_if __initdata;
173 
174 /* MTU for boot device */
175 static int ic_dev_mtu __initdata;
176 
177 #ifdef IPCONFIG_DYNAMIC
178 static DEFINE_SPINLOCK(ic_recv_lock);
179 static volatile int ic_got_reply __initdata;    /* Proto(s) that replied */
180 #endif
181 #ifdef IPCONFIG_DHCP
182 static int ic_dhcp_msgtype __initdata;	/* DHCP msg type received */
183 #endif
184 
185 
186 /*
187  *	Network devices
188  */
189 
190 struct ic_device {
191 	struct ic_device *next;
192 	struct net_device *dev;
193 	unsigned short flags;
194 	short able;
195 	__be32 xid;
196 };
197 
198 static struct ic_device *ic_first_dev __initdata;	/* List of open device */
199 static struct ic_device *ic_dev __initdata;		/* Selected device */
200 
201 static bool __init ic_is_init_dev(struct net_device *dev)
202 {
203 	if (dev->flags & IFF_LOOPBACK)
204 		return false;
205 	return user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
206 	    (!(dev->flags & IFF_LOOPBACK) &&
207 	     (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
208 	     strncmp(dev->name, "dummy", 5));
209 }
210 
211 static int __init ic_open_devs(void)
212 {
213 	struct ic_device *d, **last;
214 	struct net_device *dev;
215 	unsigned short oflags;
216 	unsigned long start, next_msg;
217 
218 	last = &ic_first_dev;
219 	rtnl_lock();
220 
221 	/* bring loopback and DSA master network devices up first */
222 	for_each_netdev(&init_net, dev) {
223 		if (!(dev->flags & IFF_LOOPBACK) && !netdev_uses_dsa(dev))
224 			continue;
225 		if (dev_change_flags(dev, dev->flags | IFF_UP, NULL) < 0)
226 			pr_err("IP-Config: Failed to open %s\n", dev->name);
227 	}
228 
229 	for_each_netdev(&init_net, dev) {
230 		if (ic_is_init_dev(dev)) {
231 			int able = 0;
232 			if (dev->mtu >= 364)
233 				able |= IC_BOOTP;
234 			else
235 				pr_warn("DHCP/BOOTP: Ignoring device %s, MTU %d too small\n",
236 					dev->name, dev->mtu);
237 			if (!(dev->flags & IFF_NOARP))
238 				able |= IC_RARP;
239 			able &= ic_proto_enabled;
240 			if (ic_proto_enabled && !able)
241 				continue;
242 			oflags = dev->flags;
243 			if (dev_change_flags(dev, oflags | IFF_UP, NULL) < 0) {
244 				pr_err("IP-Config: Failed to open %s\n",
245 				       dev->name);
246 				continue;
247 			}
248 			if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
249 				rtnl_unlock();
250 				return -ENOMEM;
251 			}
252 			d->dev = dev;
253 			*last = d;
254 			last = &d->next;
255 			d->flags = oflags;
256 			d->able = able;
257 			if (able & IC_BOOTP)
258 				get_random_bytes(&d->xid, sizeof(__be32));
259 			else
260 				d->xid = 0;
261 			ic_proto_have_if |= able;
262 			pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n",
263 				 dev->name, able, d->xid);
264 		}
265 	}
266 
267 	/* no point in waiting if we could not bring up at least one device */
268 	if (!ic_first_dev)
269 		goto have_carrier;
270 
271 	/* wait for a carrier on at least one device */
272 	start = jiffies;
273 	next_msg = start + msecs_to_jiffies(20000);
274 	while (time_before(jiffies, start +
275 			   msecs_to_jiffies(carrier_timeout * 1000))) {
276 		int wait, elapsed;
277 
278 		for_each_netdev(&init_net, dev)
279 			if (ic_is_init_dev(dev) && netif_carrier_ok(dev))
280 				goto have_carrier;
281 
282 		msleep(1);
283 
284 		if (time_before(jiffies, next_msg))
285 			continue;
286 
287 		elapsed = jiffies_to_msecs(jiffies - start);
288 		wait = (carrier_timeout * 1000 - elapsed + 500) / 1000;
289 		pr_info("Waiting up to %d more seconds for network.\n", wait);
290 		next_msg = jiffies + msecs_to_jiffies(20000);
291 	}
292 have_carrier:
293 	rtnl_unlock();
294 
295 	*last = NULL;
296 
297 	if (!ic_first_dev) {
298 		if (user_dev_name[0])
299 			pr_err("IP-Config: Device `%s' not found\n",
300 			       user_dev_name);
301 		else
302 			pr_err("IP-Config: No network devices available\n");
303 		return -ENODEV;
304 	}
305 	return 0;
306 }
307 
308 static void __init ic_close_devs(void)
309 {
310 	struct ic_device *d, *next;
311 	struct net_device *dev;
312 
313 	rtnl_lock();
314 	next = ic_first_dev;
315 	while ((d = next)) {
316 		next = d->next;
317 		dev = d->dev;
318 		if (d != ic_dev && !netdev_uses_dsa(dev)) {
319 			pr_debug("IP-Config: Downing %s\n", dev->name);
320 			dev_change_flags(dev, d->flags, NULL);
321 		}
322 		kfree(d);
323 	}
324 	rtnl_unlock();
325 }
326 
327 /*
328  *	Interface to various network functions.
329  */
330 
331 static inline void
332 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
333 {
334 	sin->sin_family = AF_INET;
335 	sin->sin_addr.s_addr = addr;
336 	sin->sin_port = port;
337 }
338 
339 /*
340  *	Set up interface addresses and routes.
341  */
342 
343 static int __init ic_setup_if(void)
344 {
345 	struct ifreq ir;
346 	struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
347 	int err;
348 
349 	memset(&ir, 0, sizeof(ir));
350 	strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name);
351 	set_sockaddr(sin, ic_myaddr, 0);
352 	if ((err = devinet_ioctl(&init_net, SIOCSIFADDR, &ir)) < 0) {
353 		pr_err("IP-Config: Unable to set interface address (%d)\n",
354 		       err);
355 		return -1;
356 	}
357 	set_sockaddr(sin, ic_netmask, 0);
358 	if ((err = devinet_ioctl(&init_net, SIOCSIFNETMASK, &ir)) < 0) {
359 		pr_err("IP-Config: Unable to set interface netmask (%d)\n",
360 		       err);
361 		return -1;
362 	}
363 	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
364 	if ((err = devinet_ioctl(&init_net, SIOCSIFBRDADDR, &ir)) < 0) {
365 		pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
366 		       err);
367 		return -1;
368 	}
369 	/* Handle the case where we need non-standard MTU on the boot link (a network
370 	 * using jumbo frames, for instance).  If we can't set the mtu, don't error
371 	 * out, we'll try to muddle along.
372 	 */
373 	if (ic_dev_mtu != 0) {
374 		rtnl_lock();
375 		if ((err = dev_set_mtu(ic_dev->dev, ic_dev_mtu)) < 0)
376 			pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
377 			       ic_dev_mtu, err);
378 		rtnl_unlock();
379 	}
380 	return 0;
381 }
382 
383 static int __init ic_setup_routes(void)
384 {
385 	/* No need to setup device routes, only the default route... */
386 
387 	if (ic_gateway != NONE) {
388 		struct rtentry rm;
389 		int err;
390 
391 		memset(&rm, 0, sizeof(rm));
392 		if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
393 			pr_err("IP-Config: Gateway not on directly connected network\n");
394 			return -1;
395 		}
396 		set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
397 		set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
398 		set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
399 		rm.rt_flags = RTF_UP | RTF_GATEWAY;
400 		if ((err = ip_rt_ioctl(&init_net, SIOCADDRT, &rm)) < 0) {
401 			pr_err("IP-Config: Cannot add default route (%d)\n",
402 			       err);
403 			return -1;
404 		}
405 	}
406 
407 	return 0;
408 }
409 
410 /*
411  *	Fill in default values for all missing parameters.
412  */
413 
414 static int __init ic_defaults(void)
415 {
416 	/*
417 	 *	At this point we have no userspace running so need not
418 	 *	claim locks on system_utsname
419 	 */
420 
421 	if (!ic_host_name_set)
422 		sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
423 
424 	if (root_server_addr == NONE)
425 		root_server_addr = ic_servaddr;
426 
427 	if (ic_netmask == NONE) {
428 		if (IN_CLASSA(ntohl(ic_myaddr)))
429 			ic_netmask = htonl(IN_CLASSA_NET);
430 		else if (IN_CLASSB(ntohl(ic_myaddr)))
431 			ic_netmask = htonl(IN_CLASSB_NET);
432 		else if (IN_CLASSC(ntohl(ic_myaddr)))
433 			ic_netmask = htonl(IN_CLASSC_NET);
434 		else if (IN_CLASSE(ntohl(ic_myaddr)))
435 			ic_netmask = htonl(IN_CLASSE_NET);
436 		else {
437 			pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
438 			       &ic_myaddr);
439 			return -1;
440 		}
441 		pr_notice("IP-Config: Guessing netmask %pI4\n",
442 			  &ic_netmask);
443 	}
444 
445 	return 0;
446 }
447 
448 /*
449  *	RARP support.
450  */
451 
452 #ifdef IPCONFIG_RARP
453 
454 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
455 
456 static struct packet_type rarp_packet_type __initdata = {
457 	.type =	cpu_to_be16(ETH_P_RARP),
458 	.func =	ic_rarp_recv,
459 };
460 
461 static inline void __init ic_rarp_init(void)
462 {
463 	dev_add_pack(&rarp_packet_type);
464 }
465 
466 static inline void __init ic_rarp_cleanup(void)
467 {
468 	dev_remove_pack(&rarp_packet_type);
469 }
470 
471 /*
472  *  Process received RARP packet.
473  */
474 static int __init
475 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
476 {
477 	struct arphdr *rarp;
478 	unsigned char *rarp_ptr;
479 	__be32 sip, tip;
480 	unsigned char *tha;		/* t for "target" */
481 	struct ic_device *d;
482 
483 	if (!net_eq(dev_net(dev), &init_net))
484 		goto drop;
485 
486 	skb = skb_share_check(skb, GFP_ATOMIC);
487 	if (!skb)
488 		return NET_RX_DROP;
489 
490 	if (!pskb_may_pull(skb, sizeof(struct arphdr)))
491 		goto drop;
492 
493 	/* Basic sanity checks can be done without the lock.  */
494 	rarp = (struct arphdr *)skb_transport_header(skb);
495 
496 	/* If this test doesn't pass, it's not IP, or we should
497 	 * ignore it anyway.
498 	 */
499 	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
500 		goto drop;
501 
502 	/* If it's not a RARP reply, delete it. */
503 	if (rarp->ar_op != htons(ARPOP_RREPLY))
504 		goto drop;
505 
506 	/* If it's not Ethernet, delete it. */
507 	if (rarp->ar_pro != htons(ETH_P_IP))
508 		goto drop;
509 
510 	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
511 		goto drop;
512 
513 	/* OK, it is all there and looks valid, process... */
514 	rarp = (struct arphdr *)skb_transport_header(skb);
515 	rarp_ptr = (unsigned char *) (rarp + 1);
516 
517 	/* One reply at a time, please. */
518 	spin_lock(&ic_recv_lock);
519 
520 	/* If we already have a reply, just drop the packet */
521 	if (ic_got_reply)
522 		goto drop_unlock;
523 
524 	/* Find the ic_device that the packet arrived on */
525 	d = ic_first_dev;
526 	while (d && d->dev != dev)
527 		d = d->next;
528 	if (!d)
529 		goto drop_unlock;	/* should never happen */
530 
531 	/* Extract variable-width fields */
532 	rarp_ptr += dev->addr_len;
533 	memcpy(&sip, rarp_ptr, 4);
534 	rarp_ptr += 4;
535 	tha = rarp_ptr;
536 	rarp_ptr += dev->addr_len;
537 	memcpy(&tip, rarp_ptr, 4);
538 
539 	/* Discard packets which are not meant for us. */
540 	if (memcmp(tha, dev->dev_addr, dev->addr_len))
541 		goto drop_unlock;
542 
543 	/* Discard packets which are not from specified server. */
544 	if (ic_servaddr != NONE && ic_servaddr != sip)
545 		goto drop_unlock;
546 
547 	/* We have a winner! */
548 	ic_dev = d;
549 	if (ic_myaddr == NONE)
550 		ic_myaddr = tip;
551 	ic_servaddr = sip;
552 	ic_addrservaddr = sip;
553 	ic_got_reply = IC_RARP;
554 
555 drop_unlock:
556 	/* Show's over.  Nothing to see here.  */
557 	spin_unlock(&ic_recv_lock);
558 
559 drop:
560 	/* Throw the packet out. */
561 	kfree_skb(skb);
562 	return 0;
563 }
564 
565 
566 /*
567  *  Send RARP request packet over a single interface.
568  */
569 static void __init ic_rarp_send_if(struct ic_device *d)
570 {
571 	struct net_device *dev = d->dev;
572 	arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
573 		 dev->dev_addr, dev->dev_addr);
574 }
575 #endif
576 
577 /*
578  *  Predefine Nameservers
579  */
580 static inline void __init ic_nameservers_predef(void)
581 {
582 	int i;
583 
584 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
585 		ic_nameservers[i] = NONE;
586 }
587 
588 /* Predefine NTP servers */
589 static inline void __init ic_ntp_servers_predef(void)
590 {
591 	int i;
592 
593 	for (i = 0; i < CONF_NTP_SERVERS_MAX; i++)
594 		ic_ntp_servers[i] = NONE;
595 }
596 
597 /*
598  *	DHCP/BOOTP support.
599  */
600 
601 #ifdef IPCONFIG_BOOTP
602 
603 struct bootp_pkt {		/* BOOTP packet format */
604 	struct iphdr iph;	/* IP header */
605 	struct udphdr udph;	/* UDP header */
606 	u8 op;			/* 1=request, 2=reply */
607 	u8 htype;		/* HW address type */
608 	u8 hlen;		/* HW address length */
609 	u8 hops;		/* Used only by gateways */
610 	__be32 xid;		/* Transaction ID */
611 	__be16 secs;		/* Seconds since we started */
612 	__be16 flags;		/* Just what it says */
613 	__be32 client_ip;		/* Client's IP address if known */
614 	__be32 your_ip;		/* Assigned IP address */
615 	__be32 server_ip;		/* (Next, e.g. NFS) Server's IP address */
616 	__be32 relay_ip;		/* IP address of BOOTP relay */
617 	u8 hw_addr[16];		/* Client's HW address */
618 	u8 serv_name[64];	/* Server host name */
619 	u8 boot_file[128];	/* Name of boot file */
620 	u8 exten[312];		/* DHCP options / BOOTP vendor extensions */
621 };
622 
623 /* packet ops */
624 #define BOOTP_REQUEST	1
625 #define BOOTP_REPLY	2
626 
627 /* DHCP message types */
628 #define DHCPDISCOVER	1
629 #define DHCPOFFER	2
630 #define DHCPREQUEST	3
631 #define DHCPDECLINE	4
632 #define DHCPACK		5
633 #define DHCPNAK		6
634 #define DHCPRELEASE	7
635 #define DHCPINFORM	8
636 
637 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
638 
639 static struct packet_type bootp_packet_type __initdata = {
640 	.type =	cpu_to_be16(ETH_P_IP),
641 	.func =	ic_bootp_recv,
642 };
643 
644 /*
645  *  Initialize DHCP/BOOTP extension fields in the request.
646  */
647 
648 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
649 
650 #ifdef IPCONFIG_DHCP
651 
652 static void __init
653 ic_dhcp_init_options(u8 *options, struct ic_device *d)
654 {
655 	u8 mt = ((ic_servaddr == NONE)
656 		 ? DHCPDISCOVER : DHCPREQUEST);
657 	u8 *e = options;
658 	int len;
659 
660 	pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
661 
662 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
663 	e += 4;
664 
665 	*e++ = 53;		/* DHCP message type */
666 	*e++ = 1;
667 	*e++ = mt;
668 
669 	if (mt == DHCPREQUEST) {
670 		*e++ = 54;	/* Server ID (IP address) */
671 		*e++ = 4;
672 		memcpy(e, &ic_servaddr, 4);
673 		e += 4;
674 
675 		*e++ = 50;	/* Requested IP address */
676 		*e++ = 4;
677 		memcpy(e, &ic_myaddr, 4);
678 		e += 4;
679 	}
680 
681 	/* always? */
682 	{
683 		static const u8 ic_req_params[] = {
684 			1,	/* Subnet mask */
685 			3,	/* Default gateway */
686 			6,	/* DNS server */
687 			12,	/* Host name */
688 			15,	/* Domain name */
689 			17,	/* Boot path */
690 			26,	/* MTU */
691 			40,	/* NIS domain name */
692 			42,	/* NTP servers */
693 		};
694 
695 		*e++ = 55;	/* Parameter request list */
696 		*e++ = sizeof(ic_req_params);
697 		memcpy(e, ic_req_params, sizeof(ic_req_params));
698 		e += sizeof(ic_req_params);
699 
700 		if (ic_host_name_set) {
701 			*e++ = 12;	/* host-name */
702 			len = strlen(utsname()->nodename);
703 			*e++ = len;
704 			memcpy(e, utsname()->nodename, len);
705 			e += len;
706 		}
707 		if (*vendor_class_identifier) {
708 			pr_info("DHCP: sending class identifier \"%s\"\n",
709 				vendor_class_identifier);
710 			*e++ = 60;	/* Class-identifier */
711 			len = strlen(vendor_class_identifier);
712 			*e++ = len;
713 			memcpy(e, vendor_class_identifier, len);
714 			e += len;
715 		}
716 		len = strlen(dhcp_client_identifier + 1);
717 		/* the minimum length of identifier is 2, include 1 byte type,
718 		 * and can not be larger than the length of options
719 		 */
720 		if (len >= 1 && len < 312 - (e - options) - 1) {
721 			*e++ = 61;
722 			*e++ = len + 1;
723 			memcpy(e, dhcp_client_identifier, len + 1);
724 			e += len + 1;
725 		}
726 	}
727 
728 	*e++ = 255;	/* End of the list */
729 }
730 
731 #endif /* IPCONFIG_DHCP */
732 
733 static void __init ic_bootp_init_ext(u8 *e)
734 {
735 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
736 	e += 4;
737 	*e++ = 1;		/* Subnet mask request */
738 	*e++ = 4;
739 	e += 4;
740 	*e++ = 3;		/* Default gateway request */
741 	*e++ = 4;
742 	e += 4;
743 #if CONF_NAMESERVERS_MAX > 0
744 	*e++ = 6;		/* (DNS) name server request */
745 	*e++ = 4 * CONF_NAMESERVERS_MAX;
746 	e += 4 * CONF_NAMESERVERS_MAX;
747 #endif
748 	*e++ = 12;		/* Host name request */
749 	*e++ = 32;
750 	e += 32;
751 	*e++ = 40;		/* NIS Domain name request */
752 	*e++ = 32;
753 	e += 32;
754 	*e++ = 17;		/* Boot path */
755 	*e++ = 40;
756 	e += 40;
757 
758 	*e++ = 57;		/* set extension buffer size for reply */
759 	*e++ = 2;
760 	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
761 	*e++ = 150;
762 
763 	*e++ = 255;		/* End of the list */
764 }
765 
766 
767 /*
768  *  Initialize the DHCP/BOOTP mechanism.
769  */
770 static inline void __init ic_bootp_init(void)
771 {
772 	/* Re-initialise all name servers and NTP servers to NONE, in case any
773 	 * were set via the "ip=" or "nfsaddrs=" kernel command line parameters:
774 	 * any IP addresses specified there will already have been decoded but
775 	 * are no longer needed
776 	 */
777 	ic_nameservers_predef();
778 	ic_ntp_servers_predef();
779 
780 	dev_add_pack(&bootp_packet_type);
781 }
782 
783 
784 /*
785  *  DHCP/BOOTP cleanup.
786  */
787 static inline void __init ic_bootp_cleanup(void)
788 {
789 	dev_remove_pack(&bootp_packet_type);
790 }
791 
792 
793 /*
794  *  Send DHCP/BOOTP request to single interface.
795  */
796 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
797 {
798 	struct net_device *dev = d->dev;
799 	struct sk_buff *skb;
800 	struct bootp_pkt *b;
801 	struct iphdr *h;
802 	int hlen = LL_RESERVED_SPACE(dev);
803 	int tlen = dev->needed_tailroom;
804 
805 	/* Allocate packet */
806 	skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
807 			GFP_KERNEL);
808 	if (!skb)
809 		return;
810 	skb_reserve(skb, hlen);
811 	b = skb_put_zero(skb, sizeof(struct bootp_pkt));
812 
813 	/* Construct IP header */
814 	skb_reset_network_header(skb);
815 	h = ip_hdr(skb);
816 	h->version = 4;
817 	h->ihl = 5;
818 	h->tot_len = htons(sizeof(struct bootp_pkt));
819 	h->frag_off = htons(IP_DF);
820 	h->ttl = 64;
821 	h->protocol = IPPROTO_UDP;
822 	h->daddr = htonl(INADDR_BROADCAST);
823 	h->check = ip_fast_csum((unsigned char *) h, h->ihl);
824 
825 	/* Construct UDP header */
826 	b->udph.source = htons(68);
827 	b->udph.dest = htons(67);
828 	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
829 	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
830 
831 	/* Construct DHCP/BOOTP header */
832 	b->op = BOOTP_REQUEST;
833 	if (dev->type < 256) /* check for false types */
834 		b->htype = dev->type;
835 	else if (dev->type == ARPHRD_FDDI)
836 		b->htype = ARPHRD_ETHER;
837 	else {
838 		pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
839 			dev->name);
840 		b->htype = dev->type; /* can cause undefined behavior */
841 	}
842 
843 	/* server_ip and your_ip address are both already zero per RFC2131 */
844 	b->hlen = dev->addr_len;
845 	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
846 	b->secs = htons(jiffies_diff / HZ);
847 	b->xid = d->xid;
848 
849 	/* add DHCP options or BOOTP extensions */
850 #ifdef IPCONFIG_DHCP
851 	if (ic_proto_enabled & IC_USE_DHCP)
852 		ic_dhcp_init_options(b->exten, d);
853 	else
854 #endif
855 		ic_bootp_init_ext(b->exten);
856 
857 	/* Chain packet down the line... */
858 	skb->dev = dev;
859 	skb->protocol = htons(ETH_P_IP);
860 	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
861 			    dev->broadcast, dev->dev_addr, skb->len) < 0) {
862 		kfree_skb(skb);
863 		printk("E");
864 		return;
865 	}
866 
867 	if (dev_queue_xmit(skb) < 0)
868 		printk("E");
869 }
870 
871 
872 /*
873  *  Copy BOOTP-supplied string if not already set.
874  */
875 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
876 {
877 	if (!len)
878 		return 0;
879 	if (len > max-1)
880 		len = max-1;
881 	memcpy(dest, src, len);
882 	dest[len] = '\0';
883 	return 1;
884 }
885 
886 
887 /*
888  *  Process BOOTP extensions.
889  */
890 static void __init ic_do_bootp_ext(u8 *ext)
891 {
892 	u8 servers;
893 	int i;
894 	__be16 mtu;
895 
896 	u8 *c;
897 
898 	pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
899 	for (c=ext+2; c<ext+2+ext[1]; c++)
900 		pr_debug(" %02x", *c);
901 	pr_debug("\n");
902 
903 	switch (*ext++) {
904 	case 1:		/* Subnet mask */
905 		if (ic_netmask == NONE)
906 			memcpy(&ic_netmask, ext+1, 4);
907 		break;
908 	case 3:		/* Default gateway */
909 		if (ic_gateway == NONE)
910 			memcpy(&ic_gateway, ext+1, 4);
911 		break;
912 	case 6:		/* DNS server */
913 		servers= *ext/4;
914 		if (servers > CONF_NAMESERVERS_MAX)
915 			servers = CONF_NAMESERVERS_MAX;
916 		for (i = 0; i < servers; i++) {
917 			if (ic_nameservers[i] == NONE)
918 				memcpy(&ic_nameservers[i], ext+1+4*i, 4);
919 		}
920 		break;
921 	case 12:	/* Host name */
922 		ic_bootp_string(utsname()->nodename, ext+1, *ext,
923 				__NEW_UTS_LEN);
924 		ic_host_name_set = 1;
925 		break;
926 	case 15:	/* Domain name (DNS) */
927 		ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
928 		break;
929 	case 17:	/* Root path */
930 		if (!root_server_path[0])
931 			ic_bootp_string(root_server_path, ext+1, *ext,
932 					sizeof(root_server_path));
933 		break;
934 	case 26:	/* Interface MTU */
935 		memcpy(&mtu, ext+1, sizeof(mtu));
936 		ic_dev_mtu = ntohs(mtu);
937 		break;
938 	case 40:	/* NIS Domain name (_not_ DNS) */
939 		ic_bootp_string(utsname()->domainname, ext+1, *ext,
940 				__NEW_UTS_LEN);
941 		break;
942 	case 42:	/* NTP servers */
943 		servers = *ext / 4;
944 		if (servers > CONF_NTP_SERVERS_MAX)
945 			servers = CONF_NTP_SERVERS_MAX;
946 		for (i = 0; i < servers; i++) {
947 			if (ic_ntp_servers[i] == NONE)
948 				memcpy(&ic_ntp_servers[i], ext+1+4*i, 4);
949 		}
950 		break;
951 	}
952 }
953 
954 
955 /*
956  *  Receive BOOTP reply.
957  */
958 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
959 {
960 	struct bootp_pkt *b;
961 	struct iphdr *h;
962 	struct ic_device *d;
963 	int len, ext_len;
964 
965 	if (!net_eq(dev_net(dev), &init_net))
966 		goto drop;
967 
968 	/* Perform verifications before taking the lock.  */
969 	if (skb->pkt_type == PACKET_OTHERHOST)
970 		goto drop;
971 
972 	skb = skb_share_check(skb, GFP_ATOMIC);
973 	if (!skb)
974 		return NET_RX_DROP;
975 
976 	if (!pskb_may_pull(skb,
977 			   sizeof(struct iphdr) +
978 			   sizeof(struct udphdr)))
979 		goto drop;
980 
981 	b = (struct bootp_pkt *)skb_network_header(skb);
982 	h = &b->iph;
983 
984 	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
985 		goto drop;
986 
987 	/* Fragments are not supported */
988 	if (ip_is_fragment(h)) {
989 		net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
990 		goto drop;
991 	}
992 
993 	if (skb->len < ntohs(h->tot_len))
994 		goto drop;
995 
996 	if (ip_fast_csum((char *) h, h->ihl))
997 		goto drop;
998 
999 	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
1000 		goto drop;
1001 
1002 	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
1003 		goto drop;
1004 
1005 	len = ntohs(b->udph.len) - sizeof(struct udphdr);
1006 	ext_len = len - (sizeof(*b) -
1007 			 sizeof(struct iphdr) -
1008 			 sizeof(struct udphdr) -
1009 			 sizeof(b->exten));
1010 	if (ext_len < 0)
1011 		goto drop;
1012 
1013 	/* Ok the front looks good, make sure we can get at the rest.  */
1014 	if (!pskb_may_pull(skb, skb->len))
1015 		goto drop;
1016 
1017 	b = (struct bootp_pkt *)skb_network_header(skb);
1018 	h = &b->iph;
1019 
1020 	/* One reply at a time, please. */
1021 	spin_lock(&ic_recv_lock);
1022 
1023 	/* If we already have a reply, just drop the packet */
1024 	if (ic_got_reply)
1025 		goto drop_unlock;
1026 
1027 	/* Find the ic_device that the packet arrived on */
1028 	d = ic_first_dev;
1029 	while (d && d->dev != dev)
1030 		d = d->next;
1031 	if (!d)
1032 		goto drop_unlock;  /* should never happen */
1033 
1034 	/* Is it a reply to our BOOTP request? */
1035 	if (b->op != BOOTP_REPLY ||
1036 	    b->xid != d->xid) {
1037 		net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1038 				    d->dev->name, b->op, b->xid);
1039 		goto drop_unlock;
1040 	}
1041 
1042 	/* Parse extensions */
1043 	if (ext_len >= 4 &&
1044 	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1045 		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1046 		u8 *ext;
1047 
1048 #ifdef IPCONFIG_DHCP
1049 		if (ic_proto_enabled & IC_USE_DHCP) {
1050 			__be32 server_id = NONE;
1051 			int mt = 0;
1052 
1053 			ext = &b->exten[4];
1054 			while (ext < end && *ext != 0xff) {
1055 				u8 *opt = ext++;
1056 				if (*opt == 0)	/* Padding */
1057 					continue;
1058 				ext += *ext + 1;
1059 				if (ext >= end)
1060 					break;
1061 				switch (*opt) {
1062 				case 53:	/* Message type */
1063 					if (opt[1])
1064 						mt = opt[2];
1065 					break;
1066 				case 54:	/* Server ID (IP address) */
1067 					if (opt[1] >= 4)
1068 						memcpy(&server_id, opt + 2, 4);
1069 					break;
1070 				}
1071 			}
1072 
1073 			pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1074 
1075 			switch (mt) {
1076 			case DHCPOFFER:
1077 				/* While in the process of accepting one offer,
1078 				 * ignore all others.
1079 				 */
1080 				if (ic_myaddr != NONE)
1081 					goto drop_unlock;
1082 
1083 				/* Let's accept that offer. */
1084 				ic_myaddr = b->your_ip;
1085 				ic_servaddr = server_id;
1086 				pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1087 					 &ic_myaddr, &b->iph.saddr);
1088 				/* The DHCP indicated server address takes
1089 				 * precedence over the bootp header one if
1090 				 * they are different.
1091 				 */
1092 				if ((server_id != NONE) &&
1093 				    (b->server_ip != server_id))
1094 					b->server_ip = ic_servaddr;
1095 				break;
1096 
1097 			case DHCPACK:
1098 				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1099 					goto drop_unlock;
1100 
1101 				/* Yeah! */
1102 				break;
1103 
1104 			default:
1105 				/* Urque.  Forget it*/
1106 				ic_myaddr = NONE;
1107 				ic_servaddr = NONE;
1108 				goto drop_unlock;
1109 			}
1110 
1111 			ic_dhcp_msgtype = mt;
1112 
1113 		}
1114 #endif /* IPCONFIG_DHCP */
1115 
1116 		ext = &b->exten[4];
1117 		while (ext < end && *ext != 0xff) {
1118 			u8 *opt = ext++;
1119 			if (*opt == 0)	/* Padding */
1120 				continue;
1121 			ext += *ext + 1;
1122 			if (ext < end)
1123 				ic_do_bootp_ext(opt);
1124 		}
1125 	}
1126 
1127 	/* We have a winner! */
1128 	ic_dev = d;
1129 	ic_myaddr = b->your_ip;
1130 	ic_servaddr = b->server_ip;
1131 	ic_addrservaddr = b->iph.saddr;
1132 	if (ic_gateway == NONE && b->relay_ip)
1133 		ic_gateway = b->relay_ip;
1134 	if (ic_nameservers[0] == NONE)
1135 		ic_nameservers[0] = ic_servaddr;
1136 	ic_got_reply = IC_BOOTP;
1137 
1138 drop_unlock:
1139 	/* Show's over.  Nothing to see here.  */
1140 	spin_unlock(&ic_recv_lock);
1141 
1142 drop:
1143 	/* Throw the packet out. */
1144 	kfree_skb(skb);
1145 
1146 	return 0;
1147 }
1148 
1149 
1150 #endif
1151 
1152 
1153 /*
1154  *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
1155  */
1156 
1157 #ifdef IPCONFIG_DYNAMIC
1158 
1159 static int __init ic_dynamic(void)
1160 {
1161 	int retries;
1162 	struct ic_device *d;
1163 	unsigned long start_jiffies, timeout, jiff;
1164 	int do_bootp = ic_proto_have_if & IC_BOOTP;
1165 	int do_rarp = ic_proto_have_if & IC_RARP;
1166 
1167 	/*
1168 	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1169 	 * This routine gets only called when some pieces of information
1170 	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1171 	 */
1172 	if (!ic_proto_enabled) {
1173 		pr_err("IP-Config: Incomplete network configuration information\n");
1174 		return -1;
1175 	}
1176 
1177 #ifdef IPCONFIG_BOOTP
1178 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1179 		pr_err("DHCP/BOOTP: No suitable device found\n");
1180 #endif
1181 #ifdef IPCONFIG_RARP
1182 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1183 		pr_err("RARP: No suitable device found\n");
1184 #endif
1185 
1186 	if (!ic_proto_have_if)
1187 		/* Error message already printed */
1188 		return -1;
1189 
1190 	/*
1191 	 * Setup protocols
1192 	 */
1193 #ifdef IPCONFIG_BOOTP
1194 	if (do_bootp)
1195 		ic_bootp_init();
1196 #endif
1197 #ifdef IPCONFIG_RARP
1198 	if (do_rarp)
1199 		ic_rarp_init();
1200 #endif
1201 
1202 	/*
1203 	 * Send requests and wait, until we get an answer. This loop
1204 	 * seems to be a terrible waste of CPU time, but actually there is
1205 	 * only one process running at all, so we don't need to use any
1206 	 * scheduler functions.
1207 	 * [Actually we could now, but the nothing else running note still
1208 	 *  applies.. - AC]
1209 	 */
1210 	pr_notice("Sending %s%s%s requests .",
1211 		  do_bootp
1212 		  ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1213 		  (do_bootp && do_rarp) ? " and " : "",
1214 		  do_rarp ? "RARP" : "");
1215 
1216 	start_jiffies = jiffies;
1217 	d = ic_first_dev;
1218 	retries = CONF_SEND_RETRIES;
1219 	get_random_bytes(&timeout, sizeof(timeout));
1220 	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1221 	for (;;) {
1222 #ifdef IPCONFIG_BOOTP
1223 		if (do_bootp && (d->able & IC_BOOTP))
1224 			ic_bootp_send_if(d, jiffies - start_jiffies);
1225 #endif
1226 #ifdef IPCONFIG_RARP
1227 		if (do_rarp && (d->able & IC_RARP))
1228 			ic_rarp_send_if(d);
1229 #endif
1230 
1231 		if (!d->next) {
1232 			jiff = jiffies + timeout;
1233 			while (time_before(jiffies, jiff) && !ic_got_reply)
1234 				schedule_timeout_uninterruptible(1);
1235 		}
1236 #ifdef IPCONFIG_DHCP
1237 		/* DHCP isn't done until we get a DHCPACK. */
1238 		if ((ic_got_reply & IC_BOOTP) &&
1239 		    (ic_proto_enabled & IC_USE_DHCP) &&
1240 		    ic_dhcp_msgtype != DHCPACK) {
1241 			ic_got_reply = 0;
1242 			/* continue on device that got the reply */
1243 			d = ic_dev;
1244 			pr_cont(",");
1245 			continue;
1246 		}
1247 #endif /* IPCONFIG_DHCP */
1248 
1249 		if (ic_got_reply) {
1250 			pr_cont(" OK\n");
1251 			break;
1252 		}
1253 
1254 		if ((d = d->next))
1255 			continue;
1256 
1257 		if (! --retries) {
1258 			pr_cont(" timed out!\n");
1259 			break;
1260 		}
1261 
1262 		d = ic_first_dev;
1263 
1264 		timeout = timeout CONF_TIMEOUT_MULT;
1265 		if (timeout > CONF_TIMEOUT_MAX)
1266 			timeout = CONF_TIMEOUT_MAX;
1267 
1268 		pr_cont(".");
1269 	}
1270 
1271 #ifdef IPCONFIG_BOOTP
1272 	if (do_bootp)
1273 		ic_bootp_cleanup();
1274 #endif
1275 #ifdef IPCONFIG_RARP
1276 	if (do_rarp)
1277 		ic_rarp_cleanup();
1278 #endif
1279 
1280 	if (!ic_got_reply) {
1281 		ic_myaddr = NONE;
1282 		return -1;
1283 	}
1284 
1285 	pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1286 		((ic_got_reply & IC_RARP) ? "RARP"
1287 		: (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1288 		&ic_addrservaddr, &ic_myaddr);
1289 
1290 	return 0;
1291 }
1292 
1293 #endif /* IPCONFIG_DYNAMIC */
1294 
1295 #ifdef CONFIG_PROC_FS
1296 /* proc_dir_entry for /proc/net/ipconfig */
1297 static struct proc_dir_entry *ipconfig_dir;
1298 
1299 /* Name servers: */
1300 static int pnp_seq_show(struct seq_file *seq, void *v)
1301 {
1302 	int i;
1303 
1304 	if (ic_proto_used & IC_PROTO)
1305 		seq_printf(seq, "#PROTO: %s\n",
1306 			   (ic_proto_used & IC_RARP) ? "RARP"
1307 			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1308 	else
1309 		seq_puts(seq, "#MANUAL\n");
1310 
1311 	if (ic_domain[0])
1312 		seq_printf(seq,
1313 			   "domain %s\n", ic_domain);
1314 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1315 		if (ic_nameservers[i] != NONE)
1316 			seq_printf(seq, "nameserver %pI4\n",
1317 				   &ic_nameservers[i]);
1318 	}
1319 	if (ic_servaddr != NONE)
1320 		seq_printf(seq, "bootserver %pI4\n",
1321 			   &ic_servaddr);
1322 	return 0;
1323 }
1324 
1325 /* Create the /proc/net/ipconfig directory */
1326 static int __init ipconfig_proc_net_init(void)
1327 {
1328 	ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net);
1329 	if (!ipconfig_dir)
1330 		return -ENOMEM;
1331 
1332 	return 0;
1333 }
1334 
1335 /* Create a new file under /proc/net/ipconfig */
1336 static int ipconfig_proc_net_create(const char *name,
1337 				    const struct file_operations *fops)
1338 {
1339 	char *pname;
1340 	struct proc_dir_entry *p;
1341 
1342 	if (!ipconfig_dir)
1343 		return -ENOMEM;
1344 
1345 	pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name);
1346 	if (!pname)
1347 		return -ENOMEM;
1348 
1349 	p = proc_create(pname, 0444, init_net.proc_net, fops);
1350 	kfree(pname);
1351 	if (!p)
1352 		return -ENOMEM;
1353 
1354 	return 0;
1355 }
1356 
1357 /* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */
1358 static int ntp_servers_seq_show(struct seq_file *seq, void *v)
1359 {
1360 	int i;
1361 
1362 	for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1363 		if (ic_ntp_servers[i] != NONE)
1364 			seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]);
1365 	}
1366 	return 0;
1367 }
1368 DEFINE_SHOW_ATTRIBUTE(ntp_servers_seq);
1369 #endif /* CONFIG_PROC_FS */
1370 
1371 /*
1372  *  Extract IP address from the parameter string if needed. Note that we
1373  *  need to have root_server_addr set _before_ IPConfig gets called as it
1374  *  can override it.
1375  */
1376 __be32 __init root_nfs_parse_addr(char *name)
1377 {
1378 	__be32 addr;
1379 	int octets = 0;
1380 	char *cp, *cq;
1381 
1382 	cp = cq = name;
1383 	while (octets < 4) {
1384 		while (*cp >= '0' && *cp <= '9')
1385 			cp++;
1386 		if (cp == cq || cp - cq > 3)
1387 			break;
1388 		if (*cp == '.' || octets == 3)
1389 			octets++;
1390 		if (octets < 4)
1391 			cp++;
1392 		cq = cp;
1393 	}
1394 	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1395 		if (*cp == ':')
1396 			*cp++ = '\0';
1397 		addr = in_aton(name);
1398 		memmove(name, cp, strlen(cp) + 1);
1399 	} else
1400 		addr = NONE;
1401 
1402 	return addr;
1403 }
1404 
1405 #define DEVICE_WAIT_MAX		12 /* 12 seconds */
1406 
1407 static int __init wait_for_devices(void)
1408 {
1409 	int i;
1410 
1411 	for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1412 		struct net_device *dev;
1413 		int found = 0;
1414 
1415 		rtnl_lock();
1416 		for_each_netdev(&init_net, dev) {
1417 			if (ic_is_init_dev(dev)) {
1418 				found = 1;
1419 				break;
1420 			}
1421 		}
1422 		rtnl_unlock();
1423 		if (found)
1424 			return 0;
1425 		ssleep(1);
1426 	}
1427 	return -ENODEV;
1428 }
1429 
1430 /*
1431  *	IP Autoconfig dispatcher.
1432  */
1433 
1434 static int __init ip_auto_config(void)
1435 {
1436 	__be32 addr;
1437 #ifdef IPCONFIG_DYNAMIC
1438 	int retries = CONF_OPEN_RETRIES;
1439 #endif
1440 	int err;
1441 	unsigned int i;
1442 
1443 	/* Initialise all name servers and NTP servers to NONE (but only if the
1444 	 * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded,
1445 	 * otherwise we'll overwrite the IP addresses specified there)
1446 	 */
1447 	if (ic_set_manually == 0) {
1448 		ic_nameservers_predef();
1449 		ic_ntp_servers_predef();
1450 	}
1451 
1452 #ifdef CONFIG_PROC_FS
1453 	proc_create_single("pnp", 0444, init_net.proc_net, pnp_seq_show);
1454 
1455 	if (ipconfig_proc_net_init() == 0)
1456 		ipconfig_proc_net_create("ntp_servers", &ntp_servers_seq_fops);
1457 #endif /* CONFIG_PROC_FS */
1458 
1459 	if (!ic_enable)
1460 		return 0;
1461 
1462 	pr_debug("IP-Config: Entered.\n");
1463 #ifdef IPCONFIG_DYNAMIC
1464  try_try_again:
1465 #endif
1466 	/* Wait for devices to appear */
1467 	err = wait_for_devices();
1468 	if (err)
1469 		return err;
1470 
1471 	/* Setup all network devices */
1472 	err = ic_open_devs();
1473 	if (err)
1474 		return err;
1475 
1476 	/* Give drivers a chance to settle */
1477 	msleep(CONF_POST_OPEN);
1478 
1479 	/*
1480 	 * If the config information is insufficient (e.g., our IP address or
1481 	 * IP address of the boot server is missing or we have multiple network
1482 	 * interfaces and no default was set), use BOOTP or RARP to get the
1483 	 * missing values.
1484 	 */
1485 	if (ic_myaddr == NONE ||
1486 #ifdef CONFIG_ROOT_NFS
1487 	    (root_server_addr == NONE &&
1488 	     ic_servaddr == NONE &&
1489 	     ROOT_DEV == Root_NFS) ||
1490 #endif
1491 	    ic_first_dev->next) {
1492 #ifdef IPCONFIG_DYNAMIC
1493 		if (ic_dynamic() < 0) {
1494 			ic_close_devs();
1495 
1496 			/*
1497 			 * I don't know why, but sometimes the
1498 			 * eepro100 driver (at least) gets upset and
1499 			 * doesn't work the first time it's opened.
1500 			 * But then if you close it and reopen it, it
1501 			 * works just fine.  So we need to try that at
1502 			 * least once before giving up.
1503 			 *
1504 			 * Also, if the root will be NFS-mounted, we
1505 			 * have nowhere to go if DHCP fails.  So we
1506 			 * just have to keep trying forever.
1507 			 *
1508 			 * 				-- Chip
1509 			 */
1510 #ifdef CONFIG_ROOT_NFS
1511 			if (ROOT_DEV ==  Root_NFS) {
1512 				pr_err("IP-Config: Retrying forever (NFS root)...\n");
1513 				goto try_try_again;
1514 			}
1515 #endif
1516 
1517 			if (--retries) {
1518 				pr_err("IP-Config: Reopening network devices...\n");
1519 				goto try_try_again;
1520 			}
1521 
1522 			/* Oh, well.  At least we tried. */
1523 			pr_err("IP-Config: Auto-configuration of network failed\n");
1524 			return -1;
1525 		}
1526 #else /* !DYNAMIC */
1527 		pr_err("IP-Config: Incomplete network configuration information\n");
1528 		ic_close_devs();
1529 		return -1;
1530 #endif /* IPCONFIG_DYNAMIC */
1531 	} else {
1532 		/* Device selected manually or only one device -> use it */
1533 		ic_dev = ic_first_dev;
1534 	}
1535 
1536 	addr = root_nfs_parse_addr(root_server_path);
1537 	if (root_server_addr == NONE)
1538 		root_server_addr = addr;
1539 
1540 	/*
1541 	 * Use defaults wherever applicable.
1542 	 */
1543 	if (ic_defaults() < 0)
1544 		return -1;
1545 
1546 	/*
1547 	 * Record which protocol was actually used.
1548 	 */
1549 #ifdef IPCONFIG_DYNAMIC
1550 	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1551 #endif
1552 
1553 #ifndef IPCONFIG_SILENT
1554 	/*
1555 	 * Clue in the operator.
1556 	 */
1557 	pr_info("IP-Config: Complete:\n");
1558 
1559 	pr_info("     device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1560 		ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1561 		&ic_myaddr, &ic_netmask, &ic_gateway);
1562 	pr_info("     host=%s, domain=%s, nis-domain=%s\n",
1563 		utsname()->nodename, ic_domain, utsname()->domainname);
1564 	pr_info("     bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1565 		&ic_servaddr, &root_server_addr, root_server_path);
1566 	if (ic_dev_mtu)
1567 		pr_cont(", mtu=%d", ic_dev_mtu);
1568 	/* Name servers (if any): */
1569 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1570 		if (ic_nameservers[i] != NONE) {
1571 			if (i == 0)
1572 				pr_info("     nameserver%u=%pI4",
1573 					i, &ic_nameservers[i]);
1574 			else
1575 				pr_cont(", nameserver%u=%pI4",
1576 					i, &ic_nameservers[i]);
1577 		}
1578 		if (i + 1 == CONF_NAMESERVERS_MAX)
1579 			pr_cont("\n");
1580 	}
1581 	/* NTP servers (if any): */
1582 	for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1583 		if (ic_ntp_servers[i] != NONE) {
1584 			if (i == 0)
1585 				pr_info("     ntpserver%u=%pI4",
1586 					i, &ic_ntp_servers[i]);
1587 			else
1588 				pr_cont(", ntpserver%u=%pI4",
1589 					i, &ic_ntp_servers[i]);
1590 		}
1591 		if (i + 1 == CONF_NTP_SERVERS_MAX)
1592 			pr_cont("\n");
1593 	}
1594 #endif /* !SILENT */
1595 
1596 	/*
1597 	 * Close all network devices except the device we've
1598 	 * autoconfigured and set up routes.
1599 	 */
1600 	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1601 		err = -1;
1602 	else
1603 		err = 0;
1604 
1605 	ic_close_devs();
1606 
1607 	return err;
1608 }
1609 
1610 late_initcall(ip_auto_config);
1611 
1612 
1613 /*
1614  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1615  *  command line parameter.  See Documentation/filesystems/nfs/nfsroot.txt.
1616  */
1617 static int __init ic_proto_name(char *name)
1618 {
1619 	if (!strcmp(name, "on") || !strcmp(name, "any")) {
1620 		return 1;
1621 	}
1622 	if (!strcmp(name, "off") || !strcmp(name, "none")) {
1623 		return 0;
1624 	}
1625 #ifdef CONFIG_IP_PNP_DHCP
1626 	else if (!strncmp(name, "dhcp", 4)) {
1627 		char *client_id;
1628 
1629 		ic_proto_enabled &= ~IC_RARP;
1630 		client_id = strstr(name, "dhcp,");
1631 		if (client_id) {
1632 			char *v;
1633 
1634 			client_id = client_id + 5;
1635 			v = strchr(client_id, ',');
1636 			if (!v)
1637 				return 1;
1638 			*v = 0;
1639 			if (kstrtou8(client_id, 0, dhcp_client_identifier))
1640 				pr_debug("DHCP: Invalid client identifier type\n");
1641 			strncpy(dhcp_client_identifier + 1, v + 1, 251);
1642 			*v = ',';
1643 		}
1644 		return 1;
1645 	}
1646 #endif
1647 #ifdef CONFIG_IP_PNP_BOOTP
1648 	else if (!strcmp(name, "bootp")) {
1649 		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1650 		return 1;
1651 	}
1652 #endif
1653 #ifdef CONFIG_IP_PNP_RARP
1654 	else if (!strcmp(name, "rarp")) {
1655 		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1656 		return 1;
1657 	}
1658 #endif
1659 #ifdef IPCONFIG_DYNAMIC
1660 	else if (!strcmp(name, "both")) {
1661 		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1662 		return 1;
1663 	}
1664 #endif
1665 	return 0;
1666 }
1667 
1668 static int __init ip_auto_config_setup(char *addrs)
1669 {
1670 	char *cp, *ip, *dp;
1671 	int num = 0;
1672 
1673 	ic_set_manually = 1;
1674 	ic_enable = 1;
1675 
1676 	/*
1677 	 * If any dhcp, bootp etc options are set, leave autoconfig on
1678 	 * and skip the below static IP processing.
1679 	 */
1680 	if (ic_proto_name(addrs))
1681 		return 1;
1682 
1683 	/* If no static IP is given, turn off autoconfig and bail.  */
1684 	if (*addrs == 0 ||
1685 	    strcmp(addrs, "off") == 0 ||
1686 	    strcmp(addrs, "none") == 0) {
1687 		ic_enable = 0;
1688 		return 1;
1689 	}
1690 
1691 	/* Initialise all name servers and NTP servers to NONE */
1692 	ic_nameservers_predef();
1693 	ic_ntp_servers_predef();
1694 
1695 	/* Parse string for static IP assignment.  */
1696 	ip = addrs;
1697 	while (ip && *ip) {
1698 		if ((cp = strchr(ip, ':')))
1699 			*cp++ = '\0';
1700 		if (strlen(ip) > 0) {
1701 			pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1702 			switch (num) {
1703 			case 0:
1704 				if ((ic_myaddr = in_aton(ip)) == ANY)
1705 					ic_myaddr = NONE;
1706 				break;
1707 			case 1:
1708 				if ((ic_servaddr = in_aton(ip)) == ANY)
1709 					ic_servaddr = NONE;
1710 				break;
1711 			case 2:
1712 				if ((ic_gateway = in_aton(ip)) == ANY)
1713 					ic_gateway = NONE;
1714 				break;
1715 			case 3:
1716 				if ((ic_netmask = in_aton(ip)) == ANY)
1717 					ic_netmask = NONE;
1718 				break;
1719 			case 4:
1720 				if ((dp = strchr(ip, '.'))) {
1721 					*dp++ = '\0';
1722 					strlcpy(utsname()->domainname, dp,
1723 						sizeof(utsname()->domainname));
1724 				}
1725 				strlcpy(utsname()->nodename, ip,
1726 					sizeof(utsname()->nodename));
1727 				ic_host_name_set = 1;
1728 				break;
1729 			case 5:
1730 				strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1731 				break;
1732 			case 6:
1733 				if (ic_proto_name(ip) == 0 &&
1734 				    ic_myaddr == NONE) {
1735 					ic_enable = 0;
1736 				}
1737 				break;
1738 			case 7:
1739 				if (CONF_NAMESERVERS_MAX >= 1) {
1740 					ic_nameservers[0] = in_aton(ip);
1741 					if (ic_nameservers[0] == ANY)
1742 						ic_nameservers[0] = NONE;
1743 				}
1744 				break;
1745 			case 8:
1746 				if (CONF_NAMESERVERS_MAX >= 2) {
1747 					ic_nameservers[1] = in_aton(ip);
1748 					if (ic_nameservers[1] == ANY)
1749 						ic_nameservers[1] = NONE;
1750 				}
1751 				break;
1752 			case 9:
1753 				if (CONF_NTP_SERVERS_MAX >= 1) {
1754 					ic_ntp_servers[0] = in_aton(ip);
1755 					if (ic_ntp_servers[0] == ANY)
1756 						ic_ntp_servers[0] = NONE;
1757 				}
1758 				break;
1759 			}
1760 		}
1761 		ip = cp;
1762 		num++;
1763 	}
1764 
1765 	return 1;
1766 }
1767 __setup("ip=", ip_auto_config_setup);
1768 
1769 static int __init nfsaddrs_config_setup(char *addrs)
1770 {
1771 	return ip_auto_config_setup(addrs);
1772 }
1773 __setup("nfsaddrs=", nfsaddrs_config_setup);
1774 
1775 static int __init vendor_class_identifier_setup(char *addrs)
1776 {
1777 	if (strlcpy(vendor_class_identifier, addrs,
1778 		    sizeof(vendor_class_identifier))
1779 	    >= sizeof(vendor_class_identifier))
1780 		pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1781 			vendor_class_identifier);
1782 	return 1;
1783 }
1784 __setup("dhcpclass=", vendor_class_identifier_setup);
1785 
1786 static int __init set_carrier_timeout(char *str)
1787 {
1788 	ssize_t ret;
1789 
1790 	if (!str)
1791 		return 0;
1792 
1793 	ret = kstrtouint(str, 0, &carrier_timeout);
1794 	if (ret)
1795 		return 0;
1796 
1797 	return 1;
1798 }
1799 __setup("carrier_timeout=", set_carrier_timeout);
1800