xref: /openbmc/linux/net/ipv4/ipconfig.c (revision 367b8112)
1 /*
2  *  Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or
3  *  user-supplied information to configure own IP address and routes.
4  *
5  *  Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
6  *
7  *  Derived from network configuration code in fs/nfs/nfsroot.c,
8  *  originally Copyright (C) 1995, 1996 Gero Kuhlmann and me.
9  *
10  *  BOOTP rewritten to construct and analyse packets itself instead
11  *  of misusing the IP layer. num_bugs_causing_wrong_arp_replies--;
12  *					     -- MJ, December 1998
13  *
14  *  Fixed ip_auto_config_setup calling at startup in the new "Linker Magic"
15  *  initialization scheme.
16  *	- Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999
17  *
18  *  DHCP support added.  To users this looks like a whole separate
19  *  protocol, but we know it's just a bag on the side of BOOTP.
20  *		-- Chip Salzenberg <chip@valinux.com>, May 2000
21  *
22  *  Ported DHCP support from 2.2.16 to 2.4.0-test4
23  *              -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000
24  *
25  *  Merged changes from 2.2.19 into 2.4.3
26  *              -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001
27  *
28  *  Multiple Nameservers in /proc/net/pnp
29  *              --  Josef Siemes <jsiemes@web.de>, Aug 2002
30  */
31 
32 #include <linux/types.h>
33 #include <linux/string.h>
34 #include <linux/kernel.h>
35 #include <linux/jiffies.h>
36 #include <linux/random.h>
37 #include <linux/init.h>
38 #include <linux/utsname.h>
39 #include <linux/in.h>
40 #include <linux/if.h>
41 #include <linux/inet.h>
42 #include <linux/inetdevice.h>
43 #include <linux/netdevice.h>
44 #include <linux/if_arp.h>
45 #include <linux/skbuff.h>
46 #include <linux/ip.h>
47 #include <linux/socket.h>
48 #include <linux/route.h>
49 #include <linux/udp.h>
50 #include <linux/proc_fs.h>
51 #include <linux/seq_file.h>
52 #include <linux/major.h>
53 #include <linux/root_dev.h>
54 #include <linux/delay.h>
55 #include <linux/nfs_fs.h>
56 #include <net/net_namespace.h>
57 #include <net/arp.h>
58 #include <net/ip.h>
59 #include <net/ipconfig.h>
60 #include <net/route.h>
61 
62 #include <asm/uaccess.h>
63 #include <net/checksum.h>
64 #include <asm/processor.h>
65 
66 /* Define this to allow debugging output */
67 #undef IPCONFIG_DEBUG
68 
69 #ifdef IPCONFIG_DEBUG
70 #define DBG(x) printk x
71 #else
72 #define DBG(x) do { } while(0)
73 #endif
74 
75 #if defined(CONFIG_IP_PNP_DHCP)
76 #define IPCONFIG_DHCP
77 #endif
78 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
79 #define IPCONFIG_BOOTP
80 #endif
81 #if defined(CONFIG_IP_PNP_RARP)
82 #define IPCONFIG_RARP
83 #endif
84 #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
85 #define IPCONFIG_DYNAMIC
86 #endif
87 
88 /* Define the friendly delay before and after opening net devices */
89 #define CONF_PRE_OPEN		500	/* Before opening: 1/2 second */
90 #define CONF_POST_OPEN		1	/* After opening: 1 second */
91 
92 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
93 #define CONF_OPEN_RETRIES 	2	/* (Re)open devices twice */
94 #define CONF_SEND_RETRIES 	6	/* Send six requests per open */
95 #define CONF_INTER_TIMEOUT	(HZ/2)	/* Inter-device timeout: 1/2 second */
96 #define CONF_BASE_TIMEOUT	(HZ*2)	/* Initial timeout: 2 seconds */
97 #define CONF_TIMEOUT_RANDOM	(HZ)	/* Maximum amount of randomization */
98 #define CONF_TIMEOUT_MULT	*7/4	/* Rate of timeout growth */
99 #define CONF_TIMEOUT_MAX	(HZ*30)	/* Maximum allowed timeout */
100 #define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
101 					   - '3' from resolv.h */
102 
103 #define NONE __constant_htonl(INADDR_NONE)
104 #define ANY __constant_htonl(INADDR_ANY)
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 = 0;		/* 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 = 0;	/* 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 __be32 ic_servaddr = NONE;	/* Boot server IP address */
138 
139 __be32 root_server_addr = NONE;	/* Address of NFS server */
140 u8 root_server_path[256] = { 0, };	/* Path to mount as root */
141 
142 /* vendor class identifier */
143 static char vendor_class_identifier[253] __initdata;
144 
145 /* Persistent data: */
146 
147 static int ic_proto_used;			/* Protocol used, if any */
148 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
149 static u8 ic_domain[64];		/* DNS (not NIS) domain name */
150 
151 /*
152  * Private state.
153  */
154 
155 /* Name of user-selected boot device */
156 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
157 
158 /* Protocols supported by available interfaces */
159 static int ic_proto_have_if __initdata = 0;
160 
161 #ifdef IPCONFIG_DYNAMIC
162 static DEFINE_SPINLOCK(ic_recv_lock);
163 static volatile int ic_got_reply __initdata = 0;    /* Proto(s) that replied */
164 #endif
165 #ifdef IPCONFIG_DHCP
166 static int ic_dhcp_msgtype __initdata = 0;	/* DHCP msg type received */
167 #endif
168 
169 
170 /*
171  *	Network devices
172  */
173 
174 struct ic_device {
175 	struct ic_device *next;
176 	struct net_device *dev;
177 	unsigned short flags;
178 	short able;
179 	__be32 xid;
180 };
181 
182 static struct ic_device *ic_first_dev __initdata = NULL;/* List of open device */
183 static struct net_device *ic_dev __initdata = NULL;	/* Selected device */
184 
185 static int __init ic_open_devs(void)
186 {
187 	struct ic_device *d, **last;
188 	struct net_device *dev;
189 	unsigned short oflags;
190 
191 	last = &ic_first_dev;
192 	rtnl_lock();
193 
194 	/* bring loopback device up first */
195 	for_each_netdev(&init_net, dev) {
196 		if (!(dev->flags & IFF_LOOPBACK))
197 			continue;
198 		if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
199 			printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
200 	}
201 
202 	for_each_netdev(&init_net, dev) {
203 		if (dev->flags & IFF_LOOPBACK)
204 			continue;
205 		if (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 			int able = 0;
210 			if (dev->mtu >= 364)
211 				able |= IC_BOOTP;
212 			else
213 				printk(KERN_WARNING "DHCP/BOOTP: Ignoring device %s, MTU %d too small", dev->name, dev->mtu);
214 			if (!(dev->flags & IFF_NOARP))
215 				able |= IC_RARP;
216 			able &= ic_proto_enabled;
217 			if (ic_proto_enabled && !able)
218 				continue;
219 			oflags = dev->flags;
220 			if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
221 				printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
222 				continue;
223 			}
224 			if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
225 				rtnl_unlock();
226 				return -1;
227 			}
228 			d->dev = dev;
229 			*last = d;
230 			last = &d->next;
231 			d->flags = oflags;
232 			d->able = able;
233 			if (able & IC_BOOTP)
234 				get_random_bytes(&d->xid, sizeof(__be32));
235 			else
236 				d->xid = 0;
237 			ic_proto_have_if |= able;
238 			DBG(("IP-Config: %s UP (able=%d, xid=%08x)\n",
239 				dev->name, able, d->xid));
240 		}
241 	}
242 	rtnl_unlock();
243 
244 	*last = NULL;
245 
246 	if (!ic_first_dev) {
247 		if (user_dev_name[0])
248 			printk(KERN_ERR "IP-Config: Device `%s' not found.\n", user_dev_name);
249 		else
250 			printk(KERN_ERR "IP-Config: No network devices available.\n");
251 		return -1;
252 	}
253 	return 0;
254 }
255 
256 static void __init ic_close_devs(void)
257 {
258 	struct ic_device *d, *next;
259 	struct net_device *dev;
260 
261 	rtnl_lock();
262 	next = ic_first_dev;
263 	while ((d = next)) {
264 		next = d->next;
265 		dev = d->dev;
266 		if (dev != ic_dev) {
267 			DBG(("IP-Config: Downing %s\n", dev->name));
268 			dev_change_flags(dev, d->flags);
269 		}
270 		kfree(d);
271 	}
272 	rtnl_unlock();
273 }
274 
275 /*
276  *	Interface to various network functions.
277  */
278 
279 static inline void
280 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
281 {
282 	sin->sin_family = AF_INET;
283 	sin->sin_addr.s_addr = addr;
284 	sin->sin_port = port;
285 }
286 
287 static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
288 {
289 	int res;
290 
291 	mm_segment_t oldfs = get_fs();
292 	set_fs(get_ds());
293 	res = devinet_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
294 	set_fs(oldfs);
295 	return res;
296 }
297 
298 static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg)
299 {
300 	int res;
301 
302 	mm_segment_t oldfs = get_fs();
303 	set_fs(get_ds());
304 	res = ip_rt_ioctl(&init_net, cmd, (void __user *) arg);
305 	set_fs(oldfs);
306 	return res;
307 }
308 
309 /*
310  *	Set up interface addresses and routes.
311  */
312 
313 static int __init ic_setup_if(void)
314 {
315 	struct ifreq ir;
316 	struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
317 	int err;
318 
319 	memset(&ir, 0, sizeof(ir));
320 	strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->name);
321 	set_sockaddr(sin, ic_myaddr, 0);
322 	if ((err = ic_dev_ioctl(SIOCSIFADDR, &ir)) < 0) {
323 		printk(KERN_ERR "IP-Config: Unable to set interface address (%d).\n", err);
324 		return -1;
325 	}
326 	set_sockaddr(sin, ic_netmask, 0);
327 	if ((err = ic_dev_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
328 		printk(KERN_ERR "IP-Config: Unable to set interface netmask (%d).\n", err);
329 		return -1;
330 	}
331 	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
332 	if ((err = ic_dev_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
333 		printk(KERN_ERR "IP-Config: Unable to set interface broadcast address (%d).\n", err);
334 		return -1;
335 	}
336 	return 0;
337 }
338 
339 static int __init ic_setup_routes(void)
340 {
341 	/* No need to setup device routes, only the default route... */
342 
343 	if (ic_gateway != NONE) {
344 		struct rtentry rm;
345 		int err;
346 
347 		memset(&rm, 0, sizeof(rm));
348 		if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
349 			printk(KERN_ERR "IP-Config: Gateway not on directly connected network.\n");
350 			return -1;
351 		}
352 		set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
353 		set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
354 		set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
355 		rm.rt_flags = RTF_UP | RTF_GATEWAY;
356 		if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) {
357 			printk(KERN_ERR "IP-Config: Cannot add default route (%d).\n", err);
358 			return -1;
359 		}
360 	}
361 
362 	return 0;
363 }
364 
365 /*
366  *	Fill in default values for all missing parameters.
367  */
368 
369 static int __init ic_defaults(void)
370 {
371 	/*
372 	 *	At this point we have no userspace running so need not
373 	 *	claim locks on system_utsname
374 	 */
375 
376 	if (!ic_host_name_set)
377 		sprintf(init_utsname()->nodename, NIPQUAD_FMT, NIPQUAD(ic_myaddr));
378 
379 	if (root_server_addr == NONE)
380 		root_server_addr = ic_servaddr;
381 
382 	if (ic_netmask == NONE) {
383 		if (IN_CLASSA(ntohl(ic_myaddr)))
384 			ic_netmask = htonl(IN_CLASSA_NET);
385 		else if (IN_CLASSB(ntohl(ic_myaddr)))
386 			ic_netmask = htonl(IN_CLASSB_NET);
387 		else if (IN_CLASSC(ntohl(ic_myaddr)))
388 			ic_netmask = htonl(IN_CLASSC_NET);
389 		else {
390 			printk(KERN_ERR "IP-Config: Unable to guess netmask for address " NIPQUAD_FMT "\n",
391 				NIPQUAD(ic_myaddr));
392 			return -1;
393 		}
394 		printk("IP-Config: Guessing netmask " NIPQUAD_FMT "\n", NIPQUAD(ic_netmask));
395 	}
396 
397 	return 0;
398 }
399 
400 /*
401  *	RARP support.
402  */
403 
404 #ifdef IPCONFIG_RARP
405 
406 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
407 
408 static struct packet_type rarp_packet_type __initdata = {
409 	.type =	__constant_htons(ETH_P_RARP),
410 	.func =	ic_rarp_recv,
411 };
412 
413 static inline void __init ic_rarp_init(void)
414 {
415 	dev_add_pack(&rarp_packet_type);
416 }
417 
418 static inline void __init ic_rarp_cleanup(void)
419 {
420 	dev_remove_pack(&rarp_packet_type);
421 }
422 
423 /*
424  *  Process received RARP packet.
425  */
426 static int __init
427 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
428 {
429 	struct arphdr *rarp;
430 	unsigned char *rarp_ptr;
431 	__be32 sip, tip;
432 	unsigned char *sha, *tha;		/* s for "source", t for "target" */
433 	struct ic_device *d;
434 
435 	if (!net_eq(dev_net(dev), &init_net))
436 		goto drop;
437 
438 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
439 		return NET_RX_DROP;
440 
441 	if (!pskb_may_pull(skb, sizeof(struct arphdr)))
442 		goto drop;
443 
444 	/* Basic sanity checks can be done without the lock.  */
445 	rarp = (struct arphdr *)skb_transport_header(skb);
446 
447 	/* If this test doesn't pass, it's not IP, or we should
448 	 * ignore it anyway.
449 	 */
450 	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
451 		goto drop;
452 
453 	/* If it's not a RARP reply, delete it. */
454 	if (rarp->ar_op != htons(ARPOP_RREPLY))
455 		goto drop;
456 
457 	/* If it's not Ethernet, delete it. */
458 	if (rarp->ar_pro != htons(ETH_P_IP))
459 		goto drop;
460 
461 	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
462 		goto drop;
463 
464 	/* OK, it is all there and looks valid, process... */
465 	rarp = (struct arphdr *)skb_transport_header(skb);
466 	rarp_ptr = (unsigned char *) (rarp + 1);
467 
468 	/* One reply at a time, please. */
469 	spin_lock(&ic_recv_lock);
470 
471 	/* If we already have a reply, just drop the packet */
472 	if (ic_got_reply)
473 		goto drop_unlock;
474 
475 	/* Find the ic_device that the packet arrived on */
476 	d = ic_first_dev;
477 	while (d && d->dev != dev)
478 		d = d->next;
479 	if (!d)
480 		goto drop_unlock;	/* should never happen */
481 
482 	/* Extract variable-width fields */
483 	sha = rarp_ptr;
484 	rarp_ptr += dev->addr_len;
485 	memcpy(&sip, rarp_ptr, 4);
486 	rarp_ptr += 4;
487 	tha = rarp_ptr;
488 	rarp_ptr += dev->addr_len;
489 	memcpy(&tip, rarp_ptr, 4);
490 
491 	/* Discard packets which are not meant for us. */
492 	if (memcmp(tha, dev->dev_addr, dev->addr_len))
493 		goto drop_unlock;
494 
495 	/* Discard packets which are not from specified server. */
496 	if (ic_servaddr != NONE && ic_servaddr != sip)
497 		goto drop_unlock;
498 
499 	/* We have a winner! */
500 	ic_dev = dev;
501 	if (ic_myaddr == NONE)
502 		ic_myaddr = tip;
503 	ic_servaddr = sip;
504 	ic_got_reply = IC_RARP;
505 
506 drop_unlock:
507 	/* Show's over.  Nothing to see here.  */
508 	spin_unlock(&ic_recv_lock);
509 
510 drop:
511 	/* Throw the packet out. */
512 	kfree_skb(skb);
513 	return 0;
514 }
515 
516 
517 /*
518  *  Send RARP request packet over a single interface.
519  */
520 static void __init ic_rarp_send_if(struct ic_device *d)
521 {
522 	struct net_device *dev = d->dev;
523 	arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
524 		 dev->dev_addr, dev->dev_addr);
525 }
526 #endif
527 
528 /*
529  *	DHCP/BOOTP support.
530  */
531 
532 #ifdef IPCONFIG_BOOTP
533 
534 struct bootp_pkt {		/* BOOTP packet format */
535 	struct iphdr iph;	/* IP header */
536 	struct udphdr udph;	/* UDP header */
537 	u8 op;			/* 1=request, 2=reply */
538 	u8 htype;		/* HW address type */
539 	u8 hlen;		/* HW address length */
540 	u8 hops;		/* Used only by gateways */
541 	__be32 xid;		/* Transaction ID */
542 	__be16 secs;		/* Seconds since we started */
543 	__be16 flags;		/* Just what it says */
544 	__be32 client_ip;		/* Client's IP address if known */
545 	__be32 your_ip;		/* Assigned IP address */
546 	__be32 server_ip;		/* (Next, e.g. NFS) Server's IP address */
547 	__be32 relay_ip;		/* IP address of BOOTP relay */
548 	u8 hw_addr[16];		/* Client's HW address */
549 	u8 serv_name[64];	/* Server host name */
550 	u8 boot_file[128];	/* Name of boot file */
551 	u8 exten[312];		/* DHCP options / BOOTP vendor extensions */
552 };
553 
554 /* packet ops */
555 #define BOOTP_REQUEST	1
556 #define BOOTP_REPLY	2
557 
558 /* DHCP message types */
559 #define DHCPDISCOVER	1
560 #define DHCPOFFER	2
561 #define DHCPREQUEST	3
562 #define DHCPDECLINE	4
563 #define DHCPACK		5
564 #define DHCPNAK		6
565 #define DHCPRELEASE	7
566 #define DHCPINFORM	8
567 
568 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
569 
570 static struct packet_type bootp_packet_type __initdata = {
571 	.type =	__constant_htons(ETH_P_IP),
572 	.func =	ic_bootp_recv,
573 };
574 
575 
576 /*
577  *  Initialize DHCP/BOOTP extension fields in the request.
578  */
579 
580 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
581 
582 #ifdef IPCONFIG_DHCP
583 
584 static void __init
585 ic_dhcp_init_options(u8 *options)
586 {
587 	u8 mt = ((ic_servaddr == NONE)
588 		 ? DHCPDISCOVER : DHCPREQUEST);
589 	u8 *e = options;
590 	int len;
591 
592 #ifdef IPCONFIG_DEBUG
593 	printk("DHCP: Sending message type %d\n", mt);
594 #endif
595 
596 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
597 	e += 4;
598 
599 	*e++ = 53;		/* DHCP message type */
600 	*e++ = 1;
601 	*e++ = mt;
602 
603 	if (mt == DHCPREQUEST) {
604 		*e++ = 54;	/* Server ID (IP address) */
605 		*e++ = 4;
606 		memcpy(e, &ic_servaddr, 4);
607 		e += 4;
608 
609 		*e++ = 50;	/* Requested IP address */
610 		*e++ = 4;
611 		memcpy(e, &ic_myaddr, 4);
612 		e += 4;
613 	}
614 
615 	/* always? */
616 	{
617 		static const u8 ic_req_params[] = {
618 			1,	/* Subnet mask */
619 			3,	/* Default gateway */
620 			6,	/* DNS server */
621 			12,	/* Host name */
622 			15,	/* Domain name */
623 			17,	/* Boot path */
624 			40,	/* NIS domain name */
625 		};
626 
627 		*e++ = 55;	/* Parameter request list */
628 		*e++ = sizeof(ic_req_params);
629 		memcpy(e, ic_req_params, sizeof(ic_req_params));
630 		e += sizeof(ic_req_params);
631 
632 		if (*vendor_class_identifier) {
633 			printk(KERN_INFO "DHCP: sending class identifier \"%s\"\n",
634 			       vendor_class_identifier);
635 			*e++ = 60;	/* Class-identifier */
636 			len = strlen(vendor_class_identifier);
637 			*e++ = len;
638 			memcpy(e, vendor_class_identifier, len);
639 			e += len;
640 		}
641 	}
642 
643 	*e++ = 255;	/* End of the list */
644 }
645 
646 #endif /* IPCONFIG_DHCP */
647 
648 static void __init ic_bootp_init_ext(u8 *e)
649 {
650 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
651 	e += 4;
652 	*e++ = 1;		/* Subnet mask request */
653 	*e++ = 4;
654 	e += 4;
655 	*e++ = 3;		/* Default gateway request */
656 	*e++ = 4;
657 	e += 4;
658 	*e++ = 5;		/* Name server request */
659 	*e++ = 8;
660 	e += 8;
661 	*e++ = 12;		/* Host name request */
662 	*e++ = 32;
663 	e += 32;
664 	*e++ = 40;		/* NIS Domain name request */
665 	*e++ = 32;
666 	e += 32;
667 	*e++ = 17;		/* Boot path */
668 	*e++ = 40;
669 	e += 40;
670 
671 	*e++ = 57;		/* set extension buffer size for reply */
672 	*e++ = 2;
673 	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
674 	*e++ = 150;
675 
676 	*e++ = 255;		/* End of the list */
677 }
678 
679 
680 /*
681  *  Initialize the DHCP/BOOTP mechanism.
682  */
683 static inline void __init ic_bootp_init(void)
684 {
685 	int i;
686 
687 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
688 		ic_nameservers[i] = NONE;
689 
690 	dev_add_pack(&bootp_packet_type);
691 }
692 
693 
694 /*
695  *  DHCP/BOOTP cleanup.
696  */
697 static inline void __init ic_bootp_cleanup(void)
698 {
699 	dev_remove_pack(&bootp_packet_type);
700 }
701 
702 
703 /*
704  *  Send DHCP/BOOTP request to single interface.
705  */
706 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
707 {
708 	struct net_device *dev = d->dev;
709 	struct sk_buff *skb;
710 	struct bootp_pkt *b;
711 	struct iphdr *h;
712 
713 	/* Allocate packet */
714 	skb = alloc_skb(sizeof(struct bootp_pkt) + LL_ALLOCATED_SPACE(dev) + 15,
715 			GFP_KERNEL);
716 	if (!skb)
717 		return;
718 	skb_reserve(skb, LL_RESERVED_SPACE(dev));
719 	b = (struct bootp_pkt *) skb_put(skb, sizeof(struct bootp_pkt));
720 	memset(b, 0, sizeof(struct bootp_pkt));
721 
722 	/* Construct IP header */
723 	skb_reset_network_header(skb);
724 	h = ip_hdr(skb);
725 	h->version = 4;
726 	h->ihl = 5;
727 	h->tot_len = htons(sizeof(struct bootp_pkt));
728 	h->frag_off = htons(IP_DF);
729 	h->ttl = 64;
730 	h->protocol = IPPROTO_UDP;
731 	h->daddr = htonl(INADDR_BROADCAST);
732 	h->check = ip_fast_csum((unsigned char *) h, h->ihl);
733 
734 	/* Construct UDP header */
735 	b->udph.source = htons(68);
736 	b->udph.dest = htons(67);
737 	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
738 	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
739 
740 	/* Construct DHCP/BOOTP header */
741 	b->op = BOOTP_REQUEST;
742 	if (dev->type < 256) /* check for false types */
743 		b->htype = dev->type;
744 	else if (dev->type == ARPHRD_IEEE802_TR) /* fix for token ring */
745 		b->htype = ARPHRD_IEEE802;
746 	else if (dev->type == ARPHRD_FDDI)
747 		b->htype = ARPHRD_ETHER;
748 	else {
749 		printk("Unknown ARP type 0x%04x for device %s\n", dev->type, dev->name);
750 		b->htype = dev->type; /* can cause undefined behavior */
751 	}
752 
753 	/* server_ip and your_ip address are both already zero per RFC2131 */
754 	b->hlen = dev->addr_len;
755 	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
756 	b->secs = htons(jiffies_diff / HZ);
757 	b->xid = d->xid;
758 
759 	/* add DHCP options or BOOTP extensions */
760 #ifdef IPCONFIG_DHCP
761 	if (ic_proto_enabled & IC_USE_DHCP)
762 		ic_dhcp_init_options(b->exten);
763 	else
764 #endif
765 		ic_bootp_init_ext(b->exten);
766 
767 	/* Chain packet down the line... */
768 	skb->dev = dev;
769 	skb->protocol = htons(ETH_P_IP);
770 	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
771 			    dev->broadcast, dev->dev_addr, skb->len) < 0 ||
772 	    dev_queue_xmit(skb) < 0)
773 		printk("E");
774 }
775 
776 
777 /*
778  *  Copy BOOTP-supplied string if not already set.
779  */
780 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
781 {
782 	if (!len)
783 		return 0;
784 	if (len > max-1)
785 		len = max-1;
786 	memcpy(dest, src, len);
787 	dest[len] = '\0';
788 	return 1;
789 }
790 
791 
792 /*
793  *  Process BOOTP extensions.
794  */
795 static void __init ic_do_bootp_ext(u8 *ext)
796 {
797        u8 servers;
798        int i;
799 
800 #ifdef IPCONFIG_DEBUG
801 	u8 *c;
802 
803 	printk("DHCP/BOOTP: Got extension %d:",*ext);
804 	for (c=ext+2; c<ext+2+ext[1]; c++)
805 		printk(" %02x", *c);
806 	printk("\n");
807 #endif
808 
809 	switch (*ext++) {
810 		case 1:		/* Subnet mask */
811 			if (ic_netmask == NONE)
812 				memcpy(&ic_netmask, ext+1, 4);
813 			break;
814 		case 3:		/* Default gateway */
815 			if (ic_gateway == NONE)
816 				memcpy(&ic_gateway, ext+1, 4);
817 			break;
818 		case 6:		/* DNS server */
819 			servers= *ext/4;
820 			if (servers > CONF_NAMESERVERS_MAX)
821 				servers = CONF_NAMESERVERS_MAX;
822 			for (i = 0; i < servers; i++) {
823 				if (ic_nameservers[i] == NONE)
824 					memcpy(&ic_nameservers[i], ext+1+4*i, 4);
825 			}
826 			break;
827 		case 12:	/* Host name */
828 			ic_bootp_string(utsname()->nodename, ext+1, *ext, __NEW_UTS_LEN);
829 			ic_host_name_set = 1;
830 			break;
831 		case 15:	/* Domain name (DNS) */
832 			ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
833 			break;
834 		case 17:	/* Root path */
835 			if (!root_server_path[0])
836 				ic_bootp_string(root_server_path, ext+1, *ext, sizeof(root_server_path));
837 			break;
838 		case 40:	/* NIS Domain name (_not_ DNS) */
839 			ic_bootp_string(utsname()->domainname, ext+1, *ext, __NEW_UTS_LEN);
840 			break;
841 	}
842 }
843 
844 
845 /*
846  *  Receive BOOTP reply.
847  */
848 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
849 {
850 	struct bootp_pkt *b;
851 	struct iphdr *h;
852 	struct ic_device *d;
853 	int len, ext_len;
854 
855 	if (!net_eq(dev_net(dev), &init_net))
856 		goto drop;
857 
858 	/* Perform verifications before taking the lock.  */
859 	if (skb->pkt_type == PACKET_OTHERHOST)
860 		goto drop;
861 
862 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
863 		return NET_RX_DROP;
864 
865 	if (!pskb_may_pull(skb,
866 			   sizeof(struct iphdr) +
867 			   sizeof(struct udphdr)))
868 		goto drop;
869 
870 	b = (struct bootp_pkt *)skb_network_header(skb);
871 	h = &b->iph;
872 
873 	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
874 		goto drop;
875 
876 	/* Fragments are not supported */
877 	if (h->frag_off & htons(IP_OFFSET | IP_MF)) {
878 		if (net_ratelimit())
879 			printk(KERN_ERR "DHCP/BOOTP: Ignoring fragmented "
880 			       "reply.\n");
881 		goto drop;
882 	}
883 
884 	if (skb->len < ntohs(h->tot_len))
885 		goto drop;
886 
887 	if (ip_fast_csum((char *) h, h->ihl))
888 		goto drop;
889 
890 	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
891 		goto drop;
892 
893 	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
894 		goto drop;
895 
896 	len = ntohs(b->udph.len) - sizeof(struct udphdr);
897 	ext_len = len - (sizeof(*b) -
898 			 sizeof(struct iphdr) -
899 			 sizeof(struct udphdr) -
900 			 sizeof(b->exten));
901 	if (ext_len < 0)
902 		goto drop;
903 
904 	/* Ok the front looks good, make sure we can get at the rest.  */
905 	if (!pskb_may_pull(skb, skb->len))
906 		goto drop;
907 
908 	b = (struct bootp_pkt *)skb_network_header(skb);
909 	h = &b->iph;
910 
911 	/* One reply at a time, please. */
912 	spin_lock(&ic_recv_lock);
913 
914 	/* If we already have a reply, just drop the packet */
915 	if (ic_got_reply)
916 		goto drop_unlock;
917 
918 	/* Find the ic_device that the packet arrived on */
919 	d = ic_first_dev;
920 	while (d && d->dev != dev)
921 		d = d->next;
922 	if (!d)
923 		goto drop_unlock;  /* should never happen */
924 
925 	/* Is it a reply to our BOOTP request? */
926 	if (b->op != BOOTP_REPLY ||
927 	    b->xid != d->xid) {
928 		if (net_ratelimit())
929 			printk(KERN_ERR "DHCP/BOOTP: Reply not for us, "
930 			       "op[%x] xid[%x]\n",
931 			       b->op, b->xid);
932 		goto drop_unlock;
933 	}
934 
935 	/* Parse extensions */
936 	if (ext_len >= 4 &&
937 	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
938 		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
939 		u8 *ext;
940 
941 #ifdef IPCONFIG_DHCP
942 		if (ic_proto_enabled & IC_USE_DHCP) {
943 			__be32 server_id = NONE;
944 			int mt = 0;
945 
946 			ext = &b->exten[4];
947 			while (ext < end && *ext != 0xff) {
948 				u8 *opt = ext++;
949 				if (*opt == 0)	/* Padding */
950 					continue;
951 				ext += *ext + 1;
952 				if (ext >= end)
953 					break;
954 				switch (*opt) {
955 				case 53:	/* Message type */
956 					if (opt[1])
957 						mt = opt[2];
958 					break;
959 				case 54:	/* Server ID (IP address) */
960 					if (opt[1] >= 4)
961 						memcpy(&server_id, opt + 2, 4);
962 					break;
963 				}
964 			}
965 
966 #ifdef IPCONFIG_DEBUG
967 			printk("DHCP: Got message type %d\n", mt);
968 #endif
969 
970 			switch (mt) {
971 			case DHCPOFFER:
972 				/* While in the process of accepting one offer,
973 				 * ignore all others.
974 				 */
975 				if (ic_myaddr != NONE)
976 					goto drop_unlock;
977 
978 				/* Let's accept that offer. */
979 				ic_myaddr = b->your_ip;
980 				ic_servaddr = server_id;
981 #ifdef IPCONFIG_DEBUG
982 				printk("DHCP: Offered address " NIPQUAD_FMT,
983 				       NIPQUAD(ic_myaddr));
984 				printk(" by server " NIPQUAD_FMT "\n",
985 				       NIPQUAD(ic_servaddr));
986 #endif
987 				/* The DHCP indicated server address takes
988 				 * precedence over the bootp header one if
989 				 * they are different.
990 				 */
991 				if ((server_id != NONE) &&
992 				    (b->server_ip != server_id))
993 					b->server_ip = ic_servaddr;
994 				break;
995 
996 			case DHCPACK:
997 				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
998 					goto drop_unlock;
999 
1000 				/* Yeah! */
1001 				break;
1002 
1003 			default:
1004 				/* Urque.  Forget it*/
1005 				ic_myaddr = NONE;
1006 				ic_servaddr = NONE;
1007 				goto drop_unlock;
1008 			}
1009 
1010 			ic_dhcp_msgtype = mt;
1011 
1012 		}
1013 #endif /* IPCONFIG_DHCP */
1014 
1015 		ext = &b->exten[4];
1016 		while (ext < end && *ext != 0xff) {
1017 			u8 *opt = ext++;
1018 			if (*opt == 0)	/* Padding */
1019 				continue;
1020 			ext += *ext + 1;
1021 			if (ext < end)
1022 				ic_do_bootp_ext(opt);
1023 		}
1024 	}
1025 
1026 	/* We have a winner! */
1027 	ic_dev = dev;
1028 	ic_myaddr = b->your_ip;
1029 	ic_servaddr = b->server_ip;
1030 	if (ic_gateway == NONE && b->relay_ip)
1031 		ic_gateway = b->relay_ip;
1032 	if (ic_nameservers[0] == NONE)
1033 		ic_nameservers[0] = ic_servaddr;
1034 	ic_got_reply = IC_BOOTP;
1035 
1036 drop_unlock:
1037 	/* Show's over.  Nothing to see here.  */
1038 	spin_unlock(&ic_recv_lock);
1039 
1040 drop:
1041 	/* Throw the packet out. */
1042 	kfree_skb(skb);
1043 
1044 	return 0;
1045 }
1046 
1047 
1048 #endif
1049 
1050 
1051 /*
1052  *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
1053  */
1054 
1055 #ifdef IPCONFIG_DYNAMIC
1056 
1057 static int __init ic_dynamic(void)
1058 {
1059 	int retries;
1060 	struct ic_device *d;
1061 	unsigned long start_jiffies, timeout, jiff;
1062 	int do_bootp = ic_proto_have_if & IC_BOOTP;
1063 	int do_rarp = ic_proto_have_if & IC_RARP;
1064 
1065 	/*
1066 	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1067 	 * This routine gets only called when some pieces of information
1068 	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1069 	 */
1070 	if (!ic_proto_enabled) {
1071 		printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
1072 		return -1;
1073 	}
1074 
1075 #ifdef IPCONFIG_BOOTP
1076 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1077 		printk(KERN_ERR "DHCP/BOOTP: No suitable device found.\n");
1078 #endif
1079 #ifdef IPCONFIG_RARP
1080 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1081 		printk(KERN_ERR "RARP: No suitable device found.\n");
1082 #endif
1083 
1084 	if (!ic_proto_have_if)
1085 		/* Error message already printed */
1086 		return -1;
1087 
1088 	/*
1089 	 * Setup protocols
1090 	 */
1091 #ifdef IPCONFIG_BOOTP
1092 	if (do_bootp)
1093 		ic_bootp_init();
1094 #endif
1095 #ifdef IPCONFIG_RARP
1096 	if (do_rarp)
1097 		ic_rarp_init();
1098 #endif
1099 
1100 	/*
1101 	 * Send requests and wait, until we get an answer. This loop
1102 	 * seems to be a terrible waste of CPU time, but actually there is
1103 	 * only one process running at all, so we don't need to use any
1104 	 * scheduler functions.
1105 	 * [Actually we could now, but the nothing else running note still
1106 	 *  applies.. - AC]
1107 	 */
1108 	printk(KERN_NOTICE "Sending %s%s%s requests .",
1109 	       do_bootp
1110 		? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1111 	       (do_bootp && do_rarp) ? " and " : "",
1112 	       do_rarp ? "RARP" : "");
1113 
1114 	start_jiffies = jiffies;
1115 	d = ic_first_dev;
1116 	retries = CONF_SEND_RETRIES;
1117 	get_random_bytes(&timeout, sizeof(timeout));
1118 	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned) CONF_TIMEOUT_RANDOM);
1119 	for (;;) {
1120 #ifdef IPCONFIG_BOOTP
1121 		if (do_bootp && (d->able & IC_BOOTP))
1122 			ic_bootp_send_if(d, jiffies - start_jiffies);
1123 #endif
1124 #ifdef IPCONFIG_RARP
1125 		if (do_rarp && (d->able & IC_RARP))
1126 			ic_rarp_send_if(d);
1127 #endif
1128 
1129 		jiff = jiffies + (d->next ? CONF_INTER_TIMEOUT : timeout);
1130 		while (time_before(jiffies, jiff) && !ic_got_reply)
1131 			schedule_timeout_uninterruptible(1);
1132 #ifdef IPCONFIG_DHCP
1133 		/* DHCP isn't done until we get a DHCPACK. */
1134 		if ((ic_got_reply & IC_BOOTP)
1135 		    && (ic_proto_enabled & IC_USE_DHCP)
1136 		    && ic_dhcp_msgtype != DHCPACK)
1137 		{
1138 			ic_got_reply = 0;
1139 			printk(",");
1140 			continue;
1141 		}
1142 #endif /* IPCONFIG_DHCP */
1143 
1144 		if (ic_got_reply) {
1145 			printk(" OK\n");
1146 			break;
1147 		}
1148 
1149 		if ((d = d->next))
1150 			continue;
1151 
1152 		if (! --retries) {
1153 			printk(" timed out!\n");
1154 			break;
1155 		}
1156 
1157 		d = ic_first_dev;
1158 
1159 		timeout = timeout CONF_TIMEOUT_MULT;
1160 		if (timeout > CONF_TIMEOUT_MAX)
1161 			timeout = CONF_TIMEOUT_MAX;
1162 
1163 		printk(".");
1164 	}
1165 
1166 #ifdef IPCONFIG_BOOTP
1167 	if (do_bootp)
1168 		ic_bootp_cleanup();
1169 #endif
1170 #ifdef IPCONFIG_RARP
1171 	if (do_rarp)
1172 		ic_rarp_cleanup();
1173 #endif
1174 
1175 	if (!ic_got_reply) {
1176 		ic_myaddr = NONE;
1177 		return -1;
1178 	}
1179 
1180 	printk("IP-Config: Got %s answer from " NIPQUAD_FMT ", ",
1181 		((ic_got_reply & IC_RARP) ? "RARP"
1182 		 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1183 		NIPQUAD(ic_servaddr));
1184 	printk("my address is " NIPQUAD_FMT "\n", NIPQUAD(ic_myaddr));
1185 
1186 	return 0;
1187 }
1188 
1189 #endif /* IPCONFIG_DYNAMIC */
1190 
1191 #ifdef CONFIG_PROC_FS
1192 
1193 static int pnp_seq_show(struct seq_file *seq, void *v)
1194 {
1195 	int i;
1196 
1197 	if (ic_proto_used & IC_PROTO)
1198 		seq_printf(seq, "#PROTO: %s\n",
1199 			   (ic_proto_used & IC_RARP) ? "RARP"
1200 			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1201 	else
1202 		seq_puts(seq, "#MANUAL\n");
1203 
1204 	if (ic_domain[0])
1205 		seq_printf(seq,
1206 			   "domain %s\n", ic_domain);
1207 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1208 		if (ic_nameservers[i] != NONE)
1209 			seq_printf(seq,
1210 				   "nameserver " NIPQUAD_FMT "\n",
1211 				   NIPQUAD(ic_nameservers[i]));
1212 	}
1213 	if (ic_servaddr != NONE)
1214 		seq_printf(seq,
1215 			   "bootserver " NIPQUAD_FMT "\n",
1216 			   NIPQUAD(ic_servaddr));
1217 	return 0;
1218 }
1219 
1220 static int pnp_seq_open(struct inode *indoe, struct file *file)
1221 {
1222 	return single_open(file, pnp_seq_show, NULL);
1223 }
1224 
1225 static const struct file_operations pnp_seq_fops = {
1226 	.owner		= THIS_MODULE,
1227 	.open		= pnp_seq_open,
1228 	.read		= seq_read,
1229 	.llseek		= seq_lseek,
1230 	.release	= single_release,
1231 };
1232 #endif /* CONFIG_PROC_FS */
1233 
1234 /*
1235  *  Extract IP address from the parameter string if needed. Note that we
1236  *  need to have root_server_addr set _before_ IPConfig gets called as it
1237  *  can override it.
1238  */
1239 __be32 __init root_nfs_parse_addr(char *name)
1240 {
1241 	__be32 addr;
1242 	int octets = 0;
1243 	char *cp, *cq;
1244 
1245 	cp = cq = name;
1246 	while (octets < 4) {
1247 		while (*cp >= '0' && *cp <= '9')
1248 			cp++;
1249 		if (cp == cq || cp - cq > 3)
1250 			break;
1251 		if (*cp == '.' || octets == 3)
1252 			octets++;
1253 		if (octets < 4)
1254 			cp++;
1255 		cq = cp;
1256 	}
1257 	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1258 		if (*cp == ':')
1259 			*cp++ = '\0';
1260 		addr = in_aton(name);
1261 		memmove(name, cp, strlen(cp) + 1);
1262 	} else
1263 		addr = NONE;
1264 
1265 	return addr;
1266 }
1267 
1268 /*
1269  *	IP Autoconfig dispatcher.
1270  */
1271 
1272 static int __init ip_auto_config(void)
1273 {
1274 	__be32 addr;
1275 
1276 #ifdef CONFIG_PROC_FS
1277 	proc_net_fops_create(&init_net, "pnp", S_IRUGO, &pnp_seq_fops);
1278 #endif /* CONFIG_PROC_FS */
1279 
1280 	if (!ic_enable)
1281 		return 0;
1282 
1283 	DBG(("IP-Config: Entered.\n"));
1284 #ifdef IPCONFIG_DYNAMIC
1285  try_try_again:
1286 #endif
1287 	/* Give hardware a chance to settle */
1288 	msleep(CONF_PRE_OPEN);
1289 
1290 	/* Setup all network devices */
1291 	if (ic_open_devs() < 0)
1292 		return -1;
1293 
1294 	/* Give drivers a chance to settle */
1295 	ssleep(CONF_POST_OPEN);
1296 
1297 	/*
1298 	 * If the config information is insufficient (e.g., our IP address or
1299 	 * IP address of the boot server is missing or we have multiple network
1300 	 * interfaces and no default was set), use BOOTP or RARP to get the
1301 	 * missing values.
1302 	 */
1303 	if (ic_myaddr == NONE ||
1304 #ifdef CONFIG_ROOT_NFS
1305 	    (root_server_addr == NONE
1306 	     && ic_servaddr == NONE
1307 	     && ROOT_DEV == Root_NFS) ||
1308 #endif
1309 	    ic_first_dev->next) {
1310 #ifdef IPCONFIG_DYNAMIC
1311 
1312 		int retries = CONF_OPEN_RETRIES;
1313 
1314 		if (ic_dynamic() < 0) {
1315 			ic_close_devs();
1316 
1317 			/*
1318 			 * I don't know why, but sometimes the
1319 			 * eepro100 driver (at least) gets upset and
1320 			 * doesn't work the first time it's opened.
1321 			 * But then if you close it and reopen it, it
1322 			 * works just fine.  So we need to try that at
1323 			 * least once before giving up.
1324 			 *
1325 			 * Also, if the root will be NFS-mounted, we
1326 			 * have nowhere to go if DHCP fails.  So we
1327 			 * just have to keep trying forever.
1328 			 *
1329 			 * 				-- Chip
1330 			 */
1331 #ifdef CONFIG_ROOT_NFS
1332 			if (ROOT_DEV ==  Root_NFS) {
1333 				printk(KERN_ERR
1334 					"IP-Config: Retrying forever (NFS root)...\n");
1335 				goto try_try_again;
1336 			}
1337 #endif
1338 
1339 			if (--retries) {
1340 				printk(KERN_ERR
1341 				       "IP-Config: Reopening network devices...\n");
1342 				goto try_try_again;
1343 			}
1344 
1345 			/* Oh, well.  At least we tried. */
1346 			printk(KERN_ERR "IP-Config: Auto-configuration of network failed.\n");
1347 			return -1;
1348 		}
1349 #else /* !DYNAMIC */
1350 		printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
1351 		ic_close_devs();
1352 		return -1;
1353 #endif /* IPCONFIG_DYNAMIC */
1354 	} else {
1355 		/* Device selected manually or only one device -> use it */
1356 		ic_dev = ic_first_dev->dev;
1357 	}
1358 
1359 	addr = root_nfs_parse_addr(root_server_path);
1360 	if (root_server_addr == NONE)
1361 		root_server_addr = addr;
1362 
1363 	/*
1364 	 * Use defaults whereever applicable.
1365 	 */
1366 	if (ic_defaults() < 0)
1367 		return -1;
1368 
1369 	/*
1370 	 * Close all network devices except the device we've
1371 	 * autoconfigured and set up routes.
1372 	 */
1373 	ic_close_devs();
1374 	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1375 		return -1;
1376 
1377 	/*
1378 	 * Record which protocol was actually used.
1379 	 */
1380 #ifdef IPCONFIG_DYNAMIC
1381 	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1382 #endif
1383 
1384 #ifndef IPCONFIG_SILENT
1385 	/*
1386 	 * Clue in the operator.
1387 	 */
1388 	printk("IP-Config: Complete:");
1389 	printk("\n     device=%s", ic_dev->name);
1390 	printk(", addr=" NIPQUAD_FMT, NIPQUAD(ic_myaddr));
1391 	printk(", mask=" NIPQUAD_FMT, NIPQUAD(ic_netmask));
1392 	printk(", gw=" NIPQUAD_FMT, NIPQUAD(ic_gateway));
1393 	printk(",\n     host=%s, domain=%s, nis-domain=%s",
1394 	       utsname()->nodename, ic_domain, utsname()->domainname);
1395 	printk(",\n     bootserver=" NIPQUAD_FMT, NIPQUAD(ic_servaddr));
1396 	printk(", rootserver=" NIPQUAD_FMT, NIPQUAD(root_server_addr));
1397 	printk(", rootpath=%s", root_server_path);
1398 	printk("\n");
1399 #endif /* !SILENT */
1400 
1401 	return 0;
1402 }
1403 
1404 late_initcall(ip_auto_config);
1405 
1406 
1407 /*
1408  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1409  *  command line parameter.  See Documentation/filesystems/nfsroot.txt.
1410  */
1411 static int __init ic_proto_name(char *name)
1412 {
1413 	if (!strcmp(name, "on") || !strcmp(name, "any")) {
1414 		return 1;
1415 	}
1416 	if (!strcmp(name, "off") || !strcmp(name, "none")) {
1417 		return 0;
1418 	}
1419 #ifdef CONFIG_IP_PNP_DHCP
1420 	else if (!strcmp(name, "dhcp")) {
1421 		ic_proto_enabled &= ~IC_RARP;
1422 		return 1;
1423 	}
1424 #endif
1425 #ifdef CONFIG_IP_PNP_BOOTP
1426 	else if (!strcmp(name, "bootp")) {
1427 		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1428 		return 1;
1429 	}
1430 #endif
1431 #ifdef CONFIG_IP_PNP_RARP
1432 	else if (!strcmp(name, "rarp")) {
1433 		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1434 		return 1;
1435 	}
1436 #endif
1437 #ifdef IPCONFIG_DYNAMIC
1438 	else if (!strcmp(name, "both")) {
1439 		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1440 		return 1;
1441 	}
1442 #endif
1443 	return 0;
1444 }
1445 
1446 static int __init ip_auto_config_setup(char *addrs)
1447 {
1448 	char *cp, *ip, *dp;
1449 	int num = 0;
1450 
1451 	ic_set_manually = 1;
1452 	ic_enable = 1;
1453 
1454 	/*
1455 	 * If any dhcp, bootp etc options are set, leave autoconfig on
1456 	 * and skip the below static IP processing.
1457 	 */
1458 	if (ic_proto_name(addrs))
1459 		return 1;
1460 
1461 	/* If no static IP is given, turn off autoconfig and bail.  */
1462 	if (*addrs == 0 ||
1463 	    strcmp(addrs, "off") == 0 ||
1464 	    strcmp(addrs, "none") == 0) {
1465 		ic_enable = 0;
1466 		return 1;
1467 	}
1468 
1469 	/* Parse string for static IP assignment.  */
1470 	ip = addrs;
1471 	while (ip && *ip) {
1472 		if ((cp = strchr(ip, ':')))
1473 			*cp++ = '\0';
1474 		if (strlen(ip) > 0) {
1475 			DBG(("IP-Config: Parameter #%d: `%s'\n", num, ip));
1476 			switch (num) {
1477 			case 0:
1478 				if ((ic_myaddr = in_aton(ip)) == ANY)
1479 					ic_myaddr = NONE;
1480 				break;
1481 			case 1:
1482 				if ((ic_servaddr = in_aton(ip)) == ANY)
1483 					ic_servaddr = NONE;
1484 				break;
1485 			case 2:
1486 				if ((ic_gateway = in_aton(ip)) == ANY)
1487 					ic_gateway = NONE;
1488 				break;
1489 			case 3:
1490 				if ((ic_netmask = in_aton(ip)) == ANY)
1491 					ic_netmask = NONE;
1492 				break;
1493 			case 4:
1494 				if ((dp = strchr(ip, '.'))) {
1495 					*dp++ = '\0';
1496 					strlcpy(utsname()->domainname, dp,
1497 						sizeof(utsname()->domainname));
1498 				}
1499 				strlcpy(utsname()->nodename, ip,
1500 					sizeof(utsname()->nodename));
1501 				ic_host_name_set = 1;
1502 				break;
1503 			case 5:
1504 				strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1505 				break;
1506 			case 6:
1507 				if (ic_proto_name(ip) == 0 &&
1508 				    ic_myaddr == NONE) {
1509 					ic_enable = 0;
1510 				}
1511 				break;
1512 			}
1513 		}
1514 		ip = cp;
1515 		num++;
1516 	}
1517 
1518 	return 1;
1519 }
1520 
1521 static int __init nfsaddrs_config_setup(char *addrs)
1522 {
1523 	return ip_auto_config_setup(addrs);
1524 }
1525 
1526 static int __init vendor_class_identifier_setup(char *addrs)
1527 {
1528 	if (strlcpy(vendor_class_identifier, addrs,
1529 		    sizeof(vendor_class_identifier))
1530 	    >= sizeof(vendor_class_identifier))
1531 		printk(KERN_WARNING "DHCP: vendorclass too long, truncated to \"%s\"",
1532 		       vendor_class_identifier);
1533 	return 1;
1534 }
1535 
1536 __setup("ip=", ip_auto_config_setup);
1537 __setup("nfsaddrs=", nfsaddrs_config_setup);
1538 __setup("dhcpclass=", vendor_class_identifier_setup);
1539