xref: /openbmc/linux/net/ipv4/ipconfig.c (revision 643d1f7f)
1 /*
2  *  $Id: ipconfig.c,v 1.46 2002/02/01 22:01:04 davem Exp $
3  *
4  *  Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or
5  *  user-supplied information to configure own IP address and routes.
6  *
7  *  Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
8  *
9  *  Derived from network configuration code in fs/nfs/nfsroot.c,
10  *  originally Copyright (C) 1995, 1996 Gero Kuhlmann and me.
11  *
12  *  BOOTP rewritten to construct and analyse packets itself instead
13  *  of misusing the IP layer. num_bugs_causing_wrong_arp_replies--;
14  *					     -- MJ, December 1998
15  *
16  *  Fixed ip_auto_config_setup calling at startup in the new "Linker Magic"
17  *  initialization scheme.
18  *	- Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999
19  *
20  *  DHCP support added.  To users this looks like a whole separate
21  *  protocol, but we know it's just a bag on the side of BOOTP.
22  *		-- Chip Salzenberg <chip@valinux.com>, May 2000
23  *
24  *  Ported DHCP support from 2.2.16 to 2.4.0-test4
25  *              -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000
26  *
27  *  Merged changes from 2.2.19 into 2.4.3
28  *              -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001
29  *
30  *  Multiple Nameservers in /proc/net/pnp
31  *              --  Josef Siemes <jsiemes@web.de>, Aug 2002
32  */
33 
34 #include <linux/types.h>
35 #include <linux/string.h>
36 #include <linux/kernel.h>
37 #include <linux/jiffies.h>
38 #include <linux/random.h>
39 #include <linux/init.h>
40 #include <linux/utsname.h>
41 #include <linux/in.h>
42 #include <linux/if.h>
43 #include <linux/inet.h>
44 #include <linux/inetdevice.h>
45 #include <linux/netdevice.h>
46 #include <linux/if_arp.h>
47 #include <linux/skbuff.h>
48 #include <linux/ip.h>
49 #include <linux/socket.h>
50 #include <linux/route.h>
51 #include <linux/udp.h>
52 #include <linux/proc_fs.h>
53 #include <linux/seq_file.h>
54 #include <linux/major.h>
55 #include <linux/root_dev.h>
56 #include <linux/delay.h>
57 #include <linux/nfs_fs.h>
58 #include <net/net_namespace.h>
59 #include <net/arp.h>
60 #include <net/ip.h>
61 #include <net/ipconfig.h>
62 #include <net/route.h>
63 
64 #include <asm/uaccess.h>
65 #include <net/checksum.h>
66 #include <asm/processor.h>
67 
68 /* Define this to allow debugging output */
69 #undef IPCONFIG_DEBUG
70 
71 #ifdef IPCONFIG_DEBUG
72 #define DBG(x) printk x
73 #else
74 #define DBG(x) do { } while(0)
75 #endif
76 
77 #if defined(CONFIG_IP_PNP_DHCP)
78 #define IPCONFIG_DHCP
79 #endif
80 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
81 #define IPCONFIG_BOOTP
82 #endif
83 #if defined(CONFIG_IP_PNP_RARP)
84 #define IPCONFIG_RARP
85 #endif
86 #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
87 #define IPCONFIG_DYNAMIC
88 #endif
89 
90 /* Define the friendly delay before and after opening net devices */
91 #define CONF_PRE_OPEN		500	/* Before opening: 1/2 second */
92 #define CONF_POST_OPEN		1	/* After opening: 1 second */
93 
94 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
95 #define CONF_OPEN_RETRIES 	2	/* (Re)open devices twice */
96 #define CONF_SEND_RETRIES 	6	/* Send six requests per open */
97 #define CONF_INTER_TIMEOUT	(HZ/2)	/* Inter-device timeout: 1/2 second */
98 #define CONF_BASE_TIMEOUT	(HZ*2)	/* Initial timeout: 2 seconds */
99 #define CONF_TIMEOUT_RANDOM	(HZ)	/* Maximum amount of randomization */
100 #define CONF_TIMEOUT_MULT	*7/4	/* Rate of timeout growth */
101 #define CONF_TIMEOUT_MAX	(HZ*30)	/* Maximum allowed timeout */
102 #define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
103 					   - '3' from resolv.h */
104 
105 #define NONE __constant_htonl(INADDR_NONE)
106 
107 /*
108  * Public IP configuration
109  */
110 
111 /* This is used by platforms which might be able to set the ipconfig
112  * variables using firmware environment vars.  If this is set, it will
113  * ignore such firmware variables.
114  */
115 int ic_set_manually __initdata = 0;		/* IPconfig parameters set manually */
116 
117 static int ic_enable __initdata = 0;		/* IP config enabled? */
118 
119 /* Protocol choice */
120 int ic_proto_enabled __initdata = 0
121 #ifdef IPCONFIG_BOOTP
122 			| IC_BOOTP
123 #endif
124 #ifdef CONFIG_IP_PNP_DHCP
125 			| IC_USE_DHCP
126 #endif
127 #ifdef IPCONFIG_RARP
128 			| IC_RARP
129 #endif
130 			;
131 
132 static int ic_host_name_set __initdata = 0;	/* Host name set by us? */
133 
134 __be32 ic_myaddr = NONE;		/* My IP address */
135 static __be32 ic_netmask = NONE;	/* Netmask for local subnet */
136 __be32 ic_gateway = NONE;	/* Gateway IP address */
137 
138 __be32 ic_servaddr = NONE;	/* Boot server IP address */
139 
140 __be32 root_server_addr = NONE;	/* Address of NFS server */
141 u8 root_server_path[256] = { 0, };	/* Path to mount as root */
142 
143 /* vendor class identifier */
144 static char vendor_class_identifier[253] __initdata;
145 
146 /* Persistent data: */
147 
148 static int ic_proto_used;			/* Protocol used, if any */
149 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
150 static u8 ic_domain[64];		/* DNS (not NIS) domain name */
151 
152 /*
153  * Private state.
154  */
155 
156 /* Name of user-selected boot device */
157 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
158 
159 /* Protocols supported by available interfaces */
160 static int ic_proto_have_if __initdata = 0;
161 
162 #ifdef IPCONFIG_DYNAMIC
163 static DEFINE_SPINLOCK(ic_recv_lock);
164 static volatile int ic_got_reply __initdata = 0;    /* Proto(s) that replied */
165 #endif
166 #ifdef IPCONFIG_DHCP
167 static int ic_dhcp_msgtype __initdata = 0;	/* DHCP msg type received */
168 #endif
169 
170 
171 /*
172  *	Network devices
173  */
174 
175 struct ic_device {
176 	struct ic_device *next;
177 	struct net_device *dev;
178 	unsigned short flags;
179 	short able;
180 	__be32 xid;
181 };
182 
183 static struct ic_device *ic_first_dev __initdata = NULL;/* List of open device */
184 static struct net_device *ic_dev __initdata = NULL;	/* Selected device */
185 
186 static int __init ic_open_devs(void)
187 {
188 	struct ic_device *d, **last;
189 	struct net_device *dev;
190 	unsigned short oflags;
191 
192 	last = &ic_first_dev;
193 	rtnl_lock();
194 
195 	/* bring loopback device up first */
196 	for_each_netdev(&init_net, dev) {
197 		if (!(dev->flags & IFF_LOOPBACK))
198 			continue;
199 		if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
200 			printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
201 	}
202 
203 	for_each_netdev(&init_net, dev) {
204 		if (dev->flags & IFF_LOOPBACK)
205 			continue;
206 		if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
207 		    (!(dev->flags & IFF_LOOPBACK) &&
208 		     (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
209 		     strncmp(dev->name, "dummy", 5))) {
210 			int able = 0;
211 			if (dev->mtu >= 364)
212 				able |= IC_BOOTP;
213 			else
214 				printk(KERN_WARNING "DHCP/BOOTP: Ignoring device %s, MTU %d too small", dev->name, dev->mtu);
215 			if (!(dev->flags & IFF_NOARP))
216 				able |= IC_RARP;
217 			able &= ic_proto_enabled;
218 			if (ic_proto_enabled && !able)
219 				continue;
220 			oflags = dev->flags;
221 			if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
222 				printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
223 				continue;
224 			}
225 			if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
226 				rtnl_unlock();
227 				return -1;
228 			}
229 			d->dev = dev;
230 			*last = d;
231 			last = &d->next;
232 			d->flags = oflags;
233 			d->able = able;
234 			if (able & IC_BOOTP)
235 				get_random_bytes(&d->xid, sizeof(__be32));
236 			else
237 				d->xid = 0;
238 			ic_proto_have_if |= able;
239 			DBG(("IP-Config: %s UP (able=%d, xid=%08x)\n",
240 				dev->name, able, d->xid));
241 		}
242 	}
243 	rtnl_unlock();
244 
245 	*last = NULL;
246 
247 	if (!ic_first_dev) {
248 		if (user_dev_name[0])
249 			printk(KERN_ERR "IP-Config: Device `%s' not found.\n", user_dev_name);
250 		else
251 			printk(KERN_ERR "IP-Config: No network devices available.\n");
252 		return -1;
253 	}
254 	return 0;
255 }
256 
257 static void __init ic_close_devs(void)
258 {
259 	struct ic_device *d, *next;
260 	struct net_device *dev;
261 
262 	rtnl_lock();
263 	next = ic_first_dev;
264 	while ((d = next)) {
265 		next = d->next;
266 		dev = d->dev;
267 		if (dev != ic_dev) {
268 			DBG(("IP-Config: Downing %s\n", dev->name));
269 			dev_change_flags(dev, d->flags);
270 		}
271 		kfree(d);
272 	}
273 	rtnl_unlock();
274 }
275 
276 /*
277  *	Interface to various network functions.
278  */
279 
280 static inline void
281 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
282 {
283 	sin->sin_family = AF_INET;
284 	sin->sin_addr.s_addr = addr;
285 	sin->sin_port = port;
286 }
287 
288 static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
289 {
290 	int res;
291 
292 	mm_segment_t oldfs = get_fs();
293 	set_fs(get_ds());
294 	res = devinet_ioctl(cmd, (struct ifreq __user *) arg);
295 	set_fs(oldfs);
296 	return res;
297 }
298 
299 static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg)
300 {
301 	int res;
302 
303 	mm_segment_t oldfs = get_fs();
304 	set_fs(get_ds());
305 	res = ip_rt_ioctl(&init_net, cmd, (void __user *) arg);
306 	set_fs(oldfs);
307 	return res;
308 }
309 
310 /*
311  *	Set up interface addresses and routes.
312  */
313 
314 static int __init ic_setup_if(void)
315 {
316 	struct ifreq ir;
317 	struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
318 	int err;
319 
320 	memset(&ir, 0, sizeof(ir));
321 	strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->name);
322 	set_sockaddr(sin, ic_myaddr, 0);
323 	if ((err = ic_dev_ioctl(SIOCSIFADDR, &ir)) < 0) {
324 		printk(KERN_ERR "IP-Config: Unable to set interface address (%d).\n", err);
325 		return -1;
326 	}
327 	set_sockaddr(sin, ic_netmask, 0);
328 	if ((err = ic_dev_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
329 		printk(KERN_ERR "IP-Config: Unable to set interface netmask (%d).\n", err);
330 		return -1;
331 	}
332 	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
333 	if ((err = ic_dev_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
334 		printk(KERN_ERR "IP-Config: Unable to set interface broadcast address (%d).\n", err);
335 		return -1;
336 	}
337 	return 0;
338 }
339 
340 static int __init ic_setup_routes(void)
341 {
342 	/* No need to setup device routes, only the default route... */
343 
344 	if (ic_gateway != NONE) {
345 		struct rtentry rm;
346 		int err;
347 
348 		memset(&rm, 0, sizeof(rm));
349 		if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
350 			printk(KERN_ERR "IP-Config: Gateway not on directly connected network.\n");
351 			return -1;
352 		}
353 		set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
354 		set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
355 		set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
356 		rm.rt_flags = RTF_UP | RTF_GATEWAY;
357 		if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) {
358 			printk(KERN_ERR "IP-Config: Cannot add default route (%d).\n", err);
359 			return -1;
360 		}
361 	}
362 
363 	return 0;
364 }
365 
366 /*
367  *	Fill in default values for all missing parameters.
368  */
369 
370 static int __init ic_defaults(void)
371 {
372 	/*
373 	 *	At this point we have no userspace running so need not
374 	 *	claim locks on system_utsname
375 	 */
376 
377 	if (!ic_host_name_set)
378 		sprintf(init_utsname()->nodename, "%u.%u.%u.%u", NIPQUAD(ic_myaddr));
379 
380 	if (root_server_addr == NONE)
381 		root_server_addr = ic_servaddr;
382 
383 	if (ic_netmask == NONE) {
384 		if (IN_CLASSA(ntohl(ic_myaddr)))
385 			ic_netmask = htonl(IN_CLASSA_NET);
386 		else if (IN_CLASSB(ntohl(ic_myaddr)))
387 			ic_netmask = htonl(IN_CLASSB_NET);
388 		else if (IN_CLASSC(ntohl(ic_myaddr)))
389 			ic_netmask = htonl(IN_CLASSC_NET);
390 		else {
391 			printk(KERN_ERR "IP-Config: Unable to guess netmask for address %u.%u.%u.%u\n",
392 				NIPQUAD(ic_myaddr));
393 			return -1;
394 		}
395 		printk("IP-Config: Guessing netmask %u.%u.%u.%u\n", NIPQUAD(ic_netmask));
396 	}
397 
398 	return 0;
399 }
400 
401 /*
402  *	RARP support.
403  */
404 
405 #ifdef IPCONFIG_RARP
406 
407 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
408 
409 static struct packet_type rarp_packet_type __initdata = {
410 	.type =	__constant_htons(ETH_P_RARP),
411 	.func =	ic_rarp_recv,
412 };
413 
414 static inline void ic_rarp_init(void)
415 {
416 	dev_add_pack(&rarp_packet_type);
417 }
418 
419 static inline void ic_rarp_cleanup(void)
420 {
421 	dev_remove_pack(&rarp_packet_type);
422 }
423 
424 /*
425  *  Process received RARP packet.
426  */
427 static int __init
428 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
429 {
430 	struct arphdr *rarp;
431 	unsigned char *rarp_ptr;
432 	__be32 sip, tip;
433 	unsigned char *sha, *tha;		/* s for "source", t for "target" */
434 	struct ic_device *d;
435 
436 	if (dev->nd_net != &init_net)
437 		goto drop;
438 
439 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
440 		return NET_RX_DROP;
441 
442 	if (!pskb_may_pull(skb, sizeof(struct arphdr)))
443 		goto drop;
444 
445 	/* Basic sanity checks can be done without the lock.  */
446 	rarp = (struct arphdr *)skb_transport_header(skb);
447 
448 	/* If this test doesn't pass, it's not IP, or we should
449 	 * ignore it anyway.
450 	 */
451 	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
452 		goto drop;
453 
454 	/* If it's not a RARP reply, delete it. */
455 	if (rarp->ar_op != htons(ARPOP_RREPLY))
456 		goto drop;
457 
458 	/* If it's not Ethernet, delete it. */
459 	if (rarp->ar_pro != htons(ETH_P_IP))
460 		goto drop;
461 
462 	if (!pskb_may_pull(skb,
463 			   sizeof(struct arphdr) +
464 			   (2 * dev->addr_len) +
465 			   (2 * 4)))
466 		goto drop;
467 
468 	/* OK, it is all there and looks valid, process... */
469 	rarp = (struct arphdr *)skb_transport_header(skb);
470 	rarp_ptr = (unsigned char *) (rarp + 1);
471 
472 	/* One reply at a time, please. */
473 	spin_lock(&ic_recv_lock);
474 
475 	/* If we already have a reply, just drop the packet */
476 	if (ic_got_reply)
477 		goto drop_unlock;
478 
479 	/* Find the ic_device that the packet arrived on */
480 	d = ic_first_dev;
481 	while (d && d->dev != dev)
482 		d = d->next;
483 	if (!d)
484 		goto drop_unlock;	/* should never happen */
485 
486 	/* Extract variable-width fields */
487 	sha = rarp_ptr;
488 	rarp_ptr += dev->addr_len;
489 	memcpy(&sip, rarp_ptr, 4);
490 	rarp_ptr += 4;
491 	tha = rarp_ptr;
492 	rarp_ptr += dev->addr_len;
493 	memcpy(&tip, rarp_ptr, 4);
494 
495 	/* Discard packets which are not meant for us. */
496 	if (memcmp(tha, dev->dev_addr, dev->addr_len))
497 		goto drop_unlock;
498 
499 	/* Discard packets which are not from specified server. */
500 	if (ic_servaddr != NONE && ic_servaddr != sip)
501 		goto drop_unlock;
502 
503 	/* We have a winner! */
504 	ic_dev = dev;
505 	if (ic_myaddr == NONE)
506 		ic_myaddr = tip;
507 	ic_servaddr = sip;
508 	ic_got_reply = IC_RARP;
509 
510 drop_unlock:
511 	/* Show's over.  Nothing to see here.  */
512 	spin_unlock(&ic_recv_lock);
513 
514 drop:
515 	/* Throw the packet out. */
516 	kfree_skb(skb);
517 	return 0;
518 }
519 
520 
521 /*
522  *  Send RARP request packet over a single interface.
523  */
524 static void __init ic_rarp_send_if(struct ic_device *d)
525 {
526 	struct net_device *dev = d->dev;
527 	arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
528 		 dev->dev_addr, dev->dev_addr);
529 }
530 #endif
531 
532 /*
533  *	DHCP/BOOTP support.
534  */
535 
536 #ifdef IPCONFIG_BOOTP
537 
538 struct bootp_pkt {		/* BOOTP packet format */
539 	struct iphdr iph;	/* IP header */
540 	struct udphdr udph;	/* UDP header */
541 	u8 op;			/* 1=request, 2=reply */
542 	u8 htype;		/* HW address type */
543 	u8 hlen;		/* HW address length */
544 	u8 hops;		/* Used only by gateways */
545 	__be32 xid;		/* Transaction ID */
546 	__be16 secs;		/* Seconds since we started */
547 	__be16 flags;		/* Just what it says */
548 	__be32 client_ip;		/* Client's IP address if known */
549 	__be32 your_ip;		/* Assigned IP address */
550 	__be32 server_ip;		/* (Next, e.g. NFS) Server's IP address */
551 	__be32 relay_ip;		/* IP address of BOOTP relay */
552 	u8 hw_addr[16];		/* Client's HW address */
553 	u8 serv_name[64];	/* Server host name */
554 	u8 boot_file[128];	/* Name of boot file */
555 	u8 exten[312];		/* DHCP options / BOOTP vendor extensions */
556 };
557 
558 /* packet ops */
559 #define BOOTP_REQUEST	1
560 #define BOOTP_REPLY	2
561 
562 /* DHCP message types */
563 #define DHCPDISCOVER	1
564 #define DHCPOFFER	2
565 #define DHCPREQUEST	3
566 #define DHCPDECLINE	4
567 #define DHCPACK		5
568 #define DHCPNAK		6
569 #define DHCPRELEASE	7
570 #define DHCPINFORM	8
571 
572 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
573 
574 static struct packet_type bootp_packet_type __initdata = {
575 	.type =	__constant_htons(ETH_P_IP),
576 	.func =	ic_bootp_recv,
577 };
578 
579 
580 /*
581  *  Initialize DHCP/BOOTP extension fields in the request.
582  */
583 
584 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
585 
586 #ifdef IPCONFIG_DHCP
587 
588 static void __init
589 ic_dhcp_init_options(u8 *options)
590 {
591 	u8 mt = ((ic_servaddr == NONE)
592 		 ? DHCPDISCOVER : DHCPREQUEST);
593 	u8 *e = options;
594 	int len;
595 
596 #ifdef IPCONFIG_DEBUG
597 	printk("DHCP: Sending message type %d\n", mt);
598 #endif
599 
600 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
601 	e += 4;
602 
603 	*e++ = 53;		/* DHCP message type */
604 	*e++ = 1;
605 	*e++ = mt;
606 
607 	if (mt == DHCPREQUEST) {
608 		*e++ = 54;	/* Server ID (IP address) */
609 		*e++ = 4;
610 		memcpy(e, &ic_servaddr, 4);
611 		e += 4;
612 
613 		*e++ = 50;	/* Requested IP address */
614 		*e++ = 4;
615 		memcpy(e, &ic_myaddr, 4);
616 		e += 4;
617 	}
618 
619 	/* always? */
620 	{
621 		static const u8 ic_req_params[] = {
622 			1,	/* Subnet mask */
623 			3,	/* Default gateway */
624 			6,	/* DNS server */
625 			12,	/* Host name */
626 			15,	/* Domain name */
627 			17,	/* Boot path */
628 			40,	/* NIS domain name */
629 		};
630 
631 		*e++ = 55;	/* Parameter request list */
632 		*e++ = sizeof(ic_req_params);
633 		memcpy(e, ic_req_params, sizeof(ic_req_params));
634 		e += sizeof(ic_req_params);
635 
636 		if (*vendor_class_identifier) {
637 			printk(KERN_INFO "DHCP: sending class identifier \"%s\"\n",
638 			       vendor_class_identifier);
639 			*e++ = 60;	/* Class-identifier */
640 			len = strlen(vendor_class_identifier);
641 			*e++ = len;
642 			memcpy(e, vendor_class_identifier, len);
643 			e += len;
644 		}
645 	}
646 
647 	*e++ = 255;	/* End of the list */
648 }
649 
650 #endif /* IPCONFIG_DHCP */
651 
652 static void __init ic_bootp_init_ext(u8 *e)
653 {
654 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
655 	e += 4;
656 	*e++ = 1;		/* Subnet mask request */
657 	*e++ = 4;
658 	e += 4;
659 	*e++ = 3;		/* Default gateway request */
660 	*e++ = 4;
661 	e += 4;
662 	*e++ = 5;		/* Name server request */
663 	*e++ = 8;
664 	e += 8;
665 	*e++ = 12;		/* Host name request */
666 	*e++ = 32;
667 	e += 32;
668 	*e++ = 40;		/* NIS Domain name request */
669 	*e++ = 32;
670 	e += 32;
671 	*e++ = 17;		/* Boot path */
672 	*e++ = 40;
673 	e += 40;
674 
675 	*e++ = 57;		/* set extension buffer size for reply */
676 	*e++ = 2;
677 	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
678 	*e++ = 150;
679 
680 	*e++ = 255;		/* End of the list */
681 }
682 
683 
684 /*
685  *  Initialize the DHCP/BOOTP mechanism.
686  */
687 static inline void ic_bootp_init(void)
688 {
689 	int i;
690 
691 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
692 		ic_nameservers[i] = NONE;
693 
694 	dev_add_pack(&bootp_packet_type);
695 }
696 
697 
698 /*
699  *  DHCP/BOOTP cleanup.
700  */
701 static inline void ic_bootp_cleanup(void)
702 {
703 	dev_remove_pack(&bootp_packet_type);
704 }
705 
706 
707 /*
708  *  Send DHCP/BOOTP request to single interface.
709  */
710 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
711 {
712 	struct net_device *dev = d->dev;
713 	struct sk_buff *skb;
714 	struct bootp_pkt *b;
715 	int hh_len = LL_RESERVED_SPACE(dev);
716 	struct iphdr *h;
717 
718 	/* Allocate packet */
719 	skb = alloc_skb(sizeof(struct bootp_pkt) + hh_len + 15, GFP_KERNEL);
720 	if (!skb)
721 		return;
722 	skb_reserve(skb, hh_len);
723 	b = (struct bootp_pkt *) skb_put(skb, sizeof(struct bootp_pkt));
724 	memset(b, 0, sizeof(struct bootp_pkt));
725 
726 	/* Construct IP header */
727 	skb_reset_network_header(skb);
728 	h = ip_hdr(skb);
729 	h->version = 4;
730 	h->ihl = 5;
731 	h->tot_len = htons(sizeof(struct bootp_pkt));
732 	h->frag_off = htons(IP_DF);
733 	h->ttl = 64;
734 	h->protocol = IPPROTO_UDP;
735 	h->daddr = htonl(INADDR_BROADCAST);
736 	h->check = ip_fast_csum((unsigned char *) h, h->ihl);
737 
738 	/* Construct UDP header */
739 	b->udph.source = htons(68);
740 	b->udph.dest = htons(67);
741 	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
742 	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
743 
744 	/* Construct DHCP/BOOTP header */
745 	b->op = BOOTP_REQUEST;
746 	if (dev->type < 256) /* check for false types */
747 		b->htype = dev->type;
748 	else if (dev->type == ARPHRD_IEEE802_TR) /* fix for token ring */
749 		b->htype = ARPHRD_IEEE802;
750 	else if (dev->type == ARPHRD_FDDI)
751 		b->htype = ARPHRD_ETHER;
752 	else {
753 		printk("Unknown ARP type 0x%04x for device %s\n", dev->type, dev->name);
754 		b->htype = dev->type; /* can cause undefined behavior */
755 	}
756 	b->hlen = dev->addr_len;
757 	b->your_ip = NONE;
758 	b->server_ip = NONE;
759 	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
760 	b->secs = htons(jiffies_diff / HZ);
761 	b->xid = d->xid;
762 
763 	/* add DHCP options or BOOTP extensions */
764 #ifdef IPCONFIG_DHCP
765 	if (ic_proto_enabled & IC_USE_DHCP)
766 		ic_dhcp_init_options(b->exten);
767 	else
768 #endif
769 		ic_bootp_init_ext(b->exten);
770 
771 	/* Chain packet down the line... */
772 	skb->dev = dev;
773 	skb->protocol = htons(ETH_P_IP);
774 	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
775 			    dev->broadcast, dev->dev_addr, skb->len) < 0 ||
776 	    dev_queue_xmit(skb) < 0)
777 		printk("E");
778 }
779 
780 
781 /*
782  *  Copy BOOTP-supplied string if not already set.
783  */
784 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
785 {
786 	if (!len)
787 		return 0;
788 	if (len > max-1)
789 		len = max-1;
790 	memcpy(dest, src, len);
791 	dest[len] = '\0';
792 	return 1;
793 }
794 
795 
796 /*
797  *  Process BOOTP extensions.
798  */
799 static void __init ic_do_bootp_ext(u8 *ext)
800 {
801        u8 servers;
802        int i;
803 
804 #ifdef IPCONFIG_DEBUG
805 	u8 *c;
806 
807 	printk("DHCP/BOOTP: Got extension %d:",*ext);
808 	for (c=ext+2; c<ext+2+ext[1]; c++)
809 		printk(" %02x", *c);
810 	printk("\n");
811 #endif
812 
813 	switch (*ext++) {
814 		case 1:		/* Subnet mask */
815 			if (ic_netmask == NONE)
816 				memcpy(&ic_netmask, ext+1, 4);
817 			break;
818 		case 3:		/* Default gateway */
819 			if (ic_gateway == NONE)
820 				memcpy(&ic_gateway, ext+1, 4);
821 			break;
822 		case 6:		/* DNS server */
823 			servers= *ext/4;
824 			if (servers > CONF_NAMESERVERS_MAX)
825 				servers = CONF_NAMESERVERS_MAX;
826 			for (i = 0; i < servers; i++) {
827 				if (ic_nameservers[i] == NONE)
828 					memcpy(&ic_nameservers[i], ext+1+4*i, 4);
829 			}
830 			break;
831 		case 12:	/* Host name */
832 			ic_bootp_string(utsname()->nodename, ext+1, *ext, __NEW_UTS_LEN);
833 			ic_host_name_set = 1;
834 			break;
835 		case 15:	/* Domain name (DNS) */
836 			ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
837 			break;
838 		case 17:	/* Root path */
839 			if (!root_server_path[0])
840 				ic_bootp_string(root_server_path, ext+1, *ext, sizeof(root_server_path));
841 			break;
842 		case 40:	/* NIS Domain name (_not_ DNS) */
843 			ic_bootp_string(utsname()->domainname, ext+1, *ext, __NEW_UTS_LEN);
844 			break;
845 	}
846 }
847 
848 
849 /*
850  *  Receive BOOTP reply.
851  */
852 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
853 {
854 	struct bootp_pkt *b;
855 	struct iphdr *h;
856 	struct ic_device *d;
857 	int len, ext_len;
858 
859 	if (dev->nd_net != &init_net)
860 		goto drop;
861 
862 	/* Perform verifications before taking the lock.  */
863 	if (skb->pkt_type == PACKET_OTHERHOST)
864 		goto drop;
865 
866 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
867 		return NET_RX_DROP;
868 
869 	if (!pskb_may_pull(skb,
870 			   sizeof(struct iphdr) +
871 			   sizeof(struct udphdr)))
872 		goto drop;
873 
874 	b = (struct bootp_pkt *)skb_network_header(skb);
875 	h = &b->iph;
876 
877 	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
878 		goto drop;
879 
880 	/* Fragments are not supported */
881 	if (h->frag_off & htons(IP_OFFSET | IP_MF)) {
882 		if (net_ratelimit())
883 			printk(KERN_ERR "DHCP/BOOTP: Ignoring fragmented "
884 			       "reply.\n");
885 		goto drop;
886 	}
887 
888 	if (skb->len < ntohs(h->tot_len))
889 		goto drop;
890 
891 	if (ip_fast_csum((char *) h, h->ihl))
892 		goto drop;
893 
894 	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
895 		goto drop;
896 
897 	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
898 		goto drop;
899 
900 	len = ntohs(b->udph.len) - sizeof(struct udphdr);
901 	ext_len = len - (sizeof(*b) -
902 			 sizeof(struct iphdr) -
903 			 sizeof(struct udphdr) -
904 			 sizeof(b->exten));
905 	if (ext_len < 0)
906 		goto drop;
907 
908 	/* Ok the front looks good, make sure we can get at the rest.  */
909 	if (!pskb_may_pull(skb, skb->len))
910 		goto drop;
911 
912 	b = (struct bootp_pkt *)skb_network_header(skb);
913 	h = &b->iph;
914 
915 	/* One reply at a time, please. */
916 	spin_lock(&ic_recv_lock);
917 
918 	/* If we already have a reply, just drop the packet */
919 	if (ic_got_reply)
920 		goto drop_unlock;
921 
922 	/* Find the ic_device that the packet arrived on */
923 	d = ic_first_dev;
924 	while (d && d->dev != dev)
925 		d = d->next;
926 	if (!d)
927 		goto drop_unlock;  /* should never happen */
928 
929 	/* Is it a reply to our BOOTP request? */
930 	if (b->op != BOOTP_REPLY ||
931 	    b->xid != d->xid) {
932 		if (net_ratelimit())
933 			printk(KERN_ERR "DHCP/BOOTP: Reply not for us, "
934 			       "op[%x] xid[%x]\n",
935 			       b->op, b->xid);
936 		goto drop_unlock;
937 	}
938 
939 	/* Parse extensions */
940 	if (ext_len >= 4 &&
941 	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
942 		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
943 		u8 *ext;
944 
945 #ifdef IPCONFIG_DHCP
946 		if (ic_proto_enabled & IC_USE_DHCP) {
947 			__be32 server_id = NONE;
948 			int mt = 0;
949 
950 			ext = &b->exten[4];
951 			while (ext < end && *ext != 0xff) {
952 				u8 *opt = ext++;
953 				if (*opt == 0)	/* Padding */
954 					continue;
955 				ext += *ext + 1;
956 				if (ext >= end)
957 					break;
958 				switch (*opt) {
959 				case 53:	/* Message type */
960 					if (opt[1])
961 						mt = opt[2];
962 					break;
963 				case 54:	/* Server ID (IP address) */
964 					if (opt[1] >= 4)
965 						memcpy(&server_id, opt + 2, 4);
966 					break;
967 				}
968 			}
969 
970 #ifdef IPCONFIG_DEBUG
971 			printk("DHCP: Got message type %d\n", mt);
972 #endif
973 
974 			switch (mt) {
975 			case DHCPOFFER:
976 				/* While in the process of accepting one offer,
977 				 * ignore all others.
978 				 */
979 				if (ic_myaddr != NONE)
980 					goto drop_unlock;
981 
982 				/* Let's accept that offer. */
983 				ic_myaddr = b->your_ip;
984 				ic_servaddr = server_id;
985 #ifdef IPCONFIG_DEBUG
986 				printk("DHCP: Offered address %u.%u.%u.%u",
987 				       NIPQUAD(ic_myaddr));
988 				printk(" by server %u.%u.%u.%u\n",
989 				       NIPQUAD(ic_servaddr));
990 #endif
991 				/* The DHCP indicated server address takes
992 				 * precedence over the bootp header one if
993 				 * they are different.
994 				 */
995 				if ((server_id != NONE) &&
996 				    (b->server_ip != server_id))
997 					b->server_ip = ic_servaddr;
998 				break;
999 
1000 			case DHCPACK:
1001 				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1002 					goto drop_unlock;
1003 
1004 				/* Yeah! */
1005 				break;
1006 
1007 			default:
1008 				/* Urque.  Forget it*/
1009 				ic_myaddr = NONE;
1010 				ic_servaddr = NONE;
1011 				goto drop_unlock;
1012 			}
1013 
1014 			ic_dhcp_msgtype = mt;
1015 
1016 		}
1017 #endif /* IPCONFIG_DHCP */
1018 
1019 		ext = &b->exten[4];
1020 		while (ext < end && *ext != 0xff) {
1021 			u8 *opt = ext++;
1022 			if (*opt == 0)	/* Padding */
1023 				continue;
1024 			ext += *ext + 1;
1025 			if (ext < end)
1026 				ic_do_bootp_ext(opt);
1027 		}
1028 	}
1029 
1030 	/* We have a winner! */
1031 	ic_dev = dev;
1032 	ic_myaddr = b->your_ip;
1033 	ic_servaddr = b->server_ip;
1034 	if (ic_gateway == NONE && b->relay_ip)
1035 		ic_gateway = b->relay_ip;
1036 	if (ic_nameservers[0] == NONE)
1037 		ic_nameservers[0] = ic_servaddr;
1038 	ic_got_reply = IC_BOOTP;
1039 
1040 drop_unlock:
1041 	/* Show's over.  Nothing to see here.  */
1042 	spin_unlock(&ic_recv_lock);
1043 
1044 drop:
1045 	/* Throw the packet out. */
1046 	kfree_skb(skb);
1047 
1048 	return 0;
1049 }
1050 
1051 
1052 #endif
1053 
1054 
1055 /*
1056  *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
1057  */
1058 
1059 #ifdef IPCONFIG_DYNAMIC
1060 
1061 static int __init ic_dynamic(void)
1062 {
1063 	int retries;
1064 	struct ic_device *d;
1065 	unsigned long start_jiffies, timeout, jiff;
1066 	int do_bootp = ic_proto_have_if & IC_BOOTP;
1067 	int do_rarp = ic_proto_have_if & IC_RARP;
1068 
1069 	/*
1070 	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1071 	 * This routine gets only called when some pieces of information
1072 	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1073 	 */
1074 	if (!ic_proto_enabled) {
1075 		printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
1076 		return -1;
1077 	}
1078 
1079 #ifdef IPCONFIG_BOOTP
1080 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1081 		printk(KERN_ERR "DHCP/BOOTP: No suitable device found.\n");
1082 #endif
1083 #ifdef IPCONFIG_RARP
1084 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1085 		printk(KERN_ERR "RARP: No suitable device found.\n");
1086 #endif
1087 
1088 	if (!ic_proto_have_if)
1089 		/* Error message already printed */
1090 		return -1;
1091 
1092 	/*
1093 	 * Setup protocols
1094 	 */
1095 #ifdef IPCONFIG_BOOTP
1096 	if (do_bootp)
1097 		ic_bootp_init();
1098 #endif
1099 #ifdef IPCONFIG_RARP
1100 	if (do_rarp)
1101 		ic_rarp_init();
1102 #endif
1103 
1104 	/*
1105 	 * Send requests and wait, until we get an answer. This loop
1106 	 * seems to be a terrible waste of CPU time, but actually there is
1107 	 * only one process running at all, so we don't need to use any
1108 	 * scheduler functions.
1109 	 * [Actually we could now, but the nothing else running note still
1110 	 *  applies.. - AC]
1111 	 */
1112 	printk(KERN_NOTICE "Sending %s%s%s requests .",
1113 	       do_bootp
1114 		? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1115 	       (do_bootp && do_rarp) ? " and " : "",
1116 	       do_rarp ? "RARP" : "");
1117 
1118 	start_jiffies = jiffies;
1119 	d = ic_first_dev;
1120 	retries = CONF_SEND_RETRIES;
1121 	get_random_bytes(&timeout, sizeof(timeout));
1122 	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned) CONF_TIMEOUT_RANDOM);
1123 	for (;;) {
1124 #ifdef IPCONFIG_BOOTP
1125 		if (do_bootp && (d->able & IC_BOOTP))
1126 			ic_bootp_send_if(d, jiffies - start_jiffies);
1127 #endif
1128 #ifdef IPCONFIG_RARP
1129 		if (do_rarp && (d->able & IC_RARP))
1130 			ic_rarp_send_if(d);
1131 #endif
1132 
1133 		jiff = jiffies + (d->next ? CONF_INTER_TIMEOUT : timeout);
1134 		while (time_before(jiffies, jiff) && !ic_got_reply)
1135 			schedule_timeout_uninterruptible(1);
1136 #ifdef IPCONFIG_DHCP
1137 		/* DHCP isn't done until we get a DHCPACK. */
1138 		if ((ic_got_reply & IC_BOOTP)
1139 		    && (ic_proto_enabled & IC_USE_DHCP)
1140 		    && ic_dhcp_msgtype != DHCPACK)
1141 		{
1142 			ic_got_reply = 0;
1143 			printk(",");
1144 			continue;
1145 		}
1146 #endif /* IPCONFIG_DHCP */
1147 
1148 		if (ic_got_reply) {
1149 			printk(" OK\n");
1150 			break;
1151 		}
1152 
1153 		if ((d = d->next))
1154 			continue;
1155 
1156 		if (! --retries) {
1157 			printk(" timed out!\n");
1158 			break;
1159 		}
1160 
1161 		d = ic_first_dev;
1162 
1163 		timeout = timeout CONF_TIMEOUT_MULT;
1164 		if (timeout > CONF_TIMEOUT_MAX)
1165 			timeout = CONF_TIMEOUT_MAX;
1166 
1167 		printk(".");
1168 	}
1169 
1170 #ifdef IPCONFIG_BOOTP
1171 	if (do_bootp)
1172 		ic_bootp_cleanup();
1173 #endif
1174 #ifdef IPCONFIG_RARP
1175 	if (do_rarp)
1176 		ic_rarp_cleanup();
1177 #endif
1178 
1179 	if (!ic_got_reply) {
1180 		ic_myaddr = NONE;
1181 		return -1;
1182 	}
1183 
1184 	printk("IP-Config: Got %s answer from %u.%u.%u.%u, ",
1185 		((ic_got_reply & IC_RARP) ? "RARP"
1186 		 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1187 		NIPQUAD(ic_servaddr));
1188 	printk("my address is %u.%u.%u.%u\n", NIPQUAD(ic_myaddr));
1189 
1190 	return 0;
1191 }
1192 
1193 #endif /* IPCONFIG_DYNAMIC */
1194 
1195 #ifdef CONFIG_PROC_FS
1196 
1197 static int pnp_seq_show(struct seq_file *seq, void *v)
1198 {
1199 	int i;
1200 
1201 	if (ic_proto_used & IC_PROTO)
1202 		seq_printf(seq, "#PROTO: %s\n",
1203 			   (ic_proto_used & IC_RARP) ? "RARP"
1204 			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1205 	else
1206 		seq_puts(seq, "#MANUAL\n");
1207 
1208 	if (ic_domain[0])
1209 		seq_printf(seq,
1210 			   "domain %s\n", ic_domain);
1211 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1212 		if (ic_nameservers[i] != NONE)
1213 			seq_printf(seq,
1214 				   "nameserver %u.%u.%u.%u\n",
1215 				   NIPQUAD(ic_nameservers[i]));
1216 	}
1217 	if (ic_servaddr != NONE)
1218 		seq_printf(seq,
1219 			   "bootserver %u.%u.%u.%u\n",
1220 			   NIPQUAD(ic_servaddr));
1221 	return 0;
1222 }
1223 
1224 static int pnp_seq_open(struct inode *indoe, struct file *file)
1225 {
1226 	return single_open(file, pnp_seq_show, NULL);
1227 }
1228 
1229 static const struct file_operations pnp_seq_fops = {
1230 	.owner		= THIS_MODULE,
1231 	.open		= pnp_seq_open,
1232 	.read		= seq_read,
1233 	.llseek		= seq_lseek,
1234 	.release	= single_release,
1235 };
1236 #endif /* CONFIG_PROC_FS */
1237 
1238 /*
1239  *  Extract IP address from the parameter string if needed. Note that we
1240  *  need to have root_server_addr set _before_ IPConfig gets called as it
1241  *  can override it.
1242  */
1243 __be32 __init root_nfs_parse_addr(char *name)
1244 {
1245 	__be32 addr;
1246 	int octets = 0;
1247 	char *cp, *cq;
1248 
1249 	cp = cq = name;
1250 	while (octets < 4) {
1251 		while (*cp >= '0' && *cp <= '9')
1252 			cp++;
1253 		if (cp == cq || cp - cq > 3)
1254 			break;
1255 		if (*cp == '.' || octets == 3)
1256 			octets++;
1257 		if (octets < 4)
1258 			cp++;
1259 		cq = cp;
1260 	}
1261 	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1262 		if (*cp == ':')
1263 			*cp++ = '\0';
1264 		addr = in_aton(name);
1265 		memmove(name, cp, strlen(cp) + 1);
1266 	} else
1267 		addr = NONE;
1268 
1269 	return addr;
1270 }
1271 
1272 /*
1273  *	IP Autoconfig dispatcher.
1274  */
1275 
1276 static int __init ip_auto_config(void)
1277 {
1278 	__be32 addr;
1279 
1280 #ifdef CONFIG_PROC_FS
1281 	proc_net_fops_create(&init_net, "pnp", S_IRUGO, &pnp_seq_fops);
1282 #endif /* CONFIG_PROC_FS */
1283 
1284 	if (!ic_enable)
1285 		return 0;
1286 
1287 	DBG(("IP-Config: Entered.\n"));
1288 #ifdef IPCONFIG_DYNAMIC
1289  try_try_again:
1290 #endif
1291 	/* Give hardware a chance to settle */
1292 	msleep(CONF_PRE_OPEN);
1293 
1294 	/* Setup all network devices */
1295 	if (ic_open_devs() < 0)
1296 		return -1;
1297 
1298 	/* Give drivers a chance to settle */
1299 	ssleep(CONF_POST_OPEN);
1300 
1301 	/*
1302 	 * If the config information is insufficient (e.g., our IP address or
1303 	 * IP address of the boot server is missing or we have multiple network
1304 	 * interfaces and no default was set), use BOOTP or RARP to get the
1305 	 * missing values.
1306 	 */
1307 	if (ic_myaddr == NONE ||
1308 #ifdef CONFIG_ROOT_NFS
1309 	    (root_server_addr == NONE
1310 	     && ic_servaddr == NONE
1311 	     && ROOT_DEV == Root_NFS) ||
1312 #endif
1313 	    ic_first_dev->next) {
1314 #ifdef IPCONFIG_DYNAMIC
1315 
1316 		int retries = CONF_OPEN_RETRIES;
1317 
1318 		if (ic_dynamic() < 0) {
1319 			ic_close_devs();
1320 
1321 			/*
1322 			 * I don't know why, but sometimes the
1323 			 * eepro100 driver (at least) gets upset and
1324 			 * doesn't work the first time it's opened.
1325 			 * But then if you close it and reopen it, it
1326 			 * works just fine.  So we need to try that at
1327 			 * least once before giving up.
1328 			 *
1329 			 * Also, if the root will be NFS-mounted, we
1330 			 * have nowhere to go if DHCP fails.  So we
1331 			 * just have to keep trying forever.
1332 			 *
1333 			 * 				-- Chip
1334 			 */
1335 #ifdef CONFIG_ROOT_NFS
1336 			if (ROOT_DEV ==  Root_NFS) {
1337 				printk(KERN_ERR
1338 					"IP-Config: Retrying forever (NFS root)...\n");
1339 				goto try_try_again;
1340 			}
1341 #endif
1342 
1343 			if (--retries) {
1344 				printk(KERN_ERR
1345 				       "IP-Config: Reopening network devices...\n");
1346 				goto try_try_again;
1347 			}
1348 
1349 			/* Oh, well.  At least we tried. */
1350 			printk(KERN_ERR "IP-Config: Auto-configuration of network failed.\n");
1351 			return -1;
1352 		}
1353 #else /* !DYNAMIC */
1354 		printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
1355 		ic_close_devs();
1356 		return -1;
1357 #endif /* IPCONFIG_DYNAMIC */
1358 	} else {
1359 		/* Device selected manually or only one device -> use it */
1360 		ic_dev = ic_first_dev->dev;
1361 	}
1362 
1363 	addr = root_nfs_parse_addr(root_server_path);
1364 	if (root_server_addr == NONE)
1365 		root_server_addr = addr;
1366 
1367 	/*
1368 	 * Use defaults whereever applicable.
1369 	 */
1370 	if (ic_defaults() < 0)
1371 		return -1;
1372 
1373 	/*
1374 	 * Close all network devices except the device we've
1375 	 * autoconfigured and set up routes.
1376 	 */
1377 	ic_close_devs();
1378 	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1379 		return -1;
1380 
1381 	/*
1382 	 * Record which protocol was actually used.
1383 	 */
1384 #ifdef IPCONFIG_DYNAMIC
1385 	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1386 #endif
1387 
1388 #ifndef IPCONFIG_SILENT
1389 	/*
1390 	 * Clue in the operator.
1391 	 */
1392 	printk("IP-Config: Complete:");
1393 	printk("\n      device=%s", ic_dev->name);
1394 	printk(", addr=%u.%u.%u.%u", NIPQUAD(ic_myaddr));
1395 	printk(", mask=%u.%u.%u.%u", NIPQUAD(ic_netmask));
1396 	printk(", gw=%u.%u.%u.%u", NIPQUAD(ic_gateway));
1397 	printk(",\n     host=%s, domain=%s, nis-domain=%s",
1398 	       utsname()->nodename, ic_domain, utsname()->domainname);
1399 	printk(",\n     bootserver=%u.%u.%u.%u", NIPQUAD(ic_servaddr));
1400 	printk(", rootserver=%u.%u.%u.%u", NIPQUAD(root_server_addr));
1401 	printk(", rootpath=%s", root_server_path);
1402 	printk("\n");
1403 #endif /* !SILENT */
1404 
1405 	return 0;
1406 }
1407 
1408 late_initcall(ip_auto_config);
1409 
1410 
1411 /*
1412  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1413  *  command line parameter.  See Documentation/nfsroot.txt.
1414  */
1415 static int __init ic_proto_name(char *name)
1416 {
1417 	if (!strcmp(name, "on") || !strcmp(name, "any")) {
1418 		return 1;
1419 	}
1420 	if (!strcmp(name, "off") || !strcmp(name, "none")) {
1421 		return 0;
1422 	}
1423 #ifdef CONFIG_IP_PNP_DHCP
1424 	else if (!strcmp(name, "dhcp")) {
1425 		ic_proto_enabled &= ~IC_RARP;
1426 		return 1;
1427 	}
1428 #endif
1429 #ifdef CONFIG_IP_PNP_BOOTP
1430 	else if (!strcmp(name, "bootp")) {
1431 		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1432 		return 1;
1433 	}
1434 #endif
1435 #ifdef CONFIG_IP_PNP_RARP
1436 	else if (!strcmp(name, "rarp")) {
1437 		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1438 		return 1;
1439 	}
1440 #endif
1441 #ifdef IPCONFIG_DYNAMIC
1442 	else if (!strcmp(name, "both")) {
1443 		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1444 		return 1;
1445 	}
1446 #endif
1447 	return 0;
1448 }
1449 
1450 static int __init ip_auto_config_setup(char *addrs)
1451 {
1452 	char *cp, *ip, *dp;
1453 	int num = 0;
1454 
1455 	ic_set_manually = 1;
1456 	ic_enable = 1;
1457 
1458 	/*
1459 	 * If any dhcp, bootp etc options are set, leave autoconfig on
1460 	 * and skip the below static IP processing.
1461 	 */
1462 	if (ic_proto_name(addrs))
1463 		return 1;
1464 
1465 	/* If no static IP is given, turn off autoconfig and bail.  */
1466 	if (*addrs == 0 ||
1467 	    strcmp(addrs, "off") == 0 ||
1468 	    strcmp(addrs, "none") == 0) {
1469 		ic_enable = 0;
1470 		return 1;
1471 	}
1472 
1473 	/* Parse string for static IP assignment.  */
1474 	ip = addrs;
1475 	while (ip && *ip) {
1476 		if ((cp = strchr(ip, ':')))
1477 			*cp++ = '\0';
1478 		if (strlen(ip) > 0) {
1479 			DBG(("IP-Config: Parameter #%d: `%s'\n", num, ip));
1480 			switch (num) {
1481 			case 0:
1482 				if ((ic_myaddr = in_aton(ip)) == INADDR_ANY)
1483 					ic_myaddr = NONE;
1484 				break;
1485 			case 1:
1486 				if ((ic_servaddr = in_aton(ip)) == INADDR_ANY)
1487 					ic_servaddr = NONE;
1488 				break;
1489 			case 2:
1490 				if ((ic_gateway = in_aton(ip)) == INADDR_ANY)
1491 					ic_gateway = NONE;
1492 				break;
1493 			case 3:
1494 				if ((ic_netmask = in_aton(ip)) == INADDR_ANY)
1495 					ic_netmask = NONE;
1496 				break;
1497 			case 4:
1498 				if ((dp = strchr(ip, '.'))) {
1499 					*dp++ = '\0';
1500 					strlcpy(utsname()->domainname, dp,
1501 						sizeof(utsname()->domainname));
1502 				}
1503 				strlcpy(utsname()->nodename, ip,
1504 					sizeof(utsname()->nodename));
1505 				ic_host_name_set = 1;
1506 				break;
1507 			case 5:
1508 				strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1509 				break;
1510 			case 6:
1511 				if (ic_proto_name(ip) == 0 &&
1512 				    ic_myaddr == NONE) {
1513 					ic_enable = 0;
1514 				}
1515 				break;
1516 			}
1517 		}
1518 		ip = cp;
1519 		num++;
1520 	}
1521 
1522 	return 1;
1523 }
1524 
1525 static int __init nfsaddrs_config_setup(char *addrs)
1526 {
1527 	return ip_auto_config_setup(addrs);
1528 }
1529 
1530 static int __init vendor_class_identifier_setup(char *addrs)
1531 {
1532 	if (strlcpy(vendor_class_identifier, addrs,
1533 		    sizeof(vendor_class_identifier))
1534 	    >= sizeof(vendor_class_identifier))
1535 		printk(KERN_WARNING "DHCP: vendorclass too long, truncated to \"%s\"",
1536 		       vendor_class_identifier);
1537 	return 1;
1538 }
1539 
1540 __setup("ip=", ip_auto_config_setup);
1541 __setup("nfsaddrs=", nfsaddrs_config_setup);
1542 __setup("dhcpclass=", vendor_class_identifier_setup);
1543