xref: /openbmc/linux/net/ipv4/ipconfig.c (revision 78c99ba1)
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 cpu_to_be32(INADDR_NONE)
104 #define ANY cpu_to_be32(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 u32 ic_dev_xid;		/* Device under configuration */
143 
144 /* vendor class identifier */
145 static char vendor_class_identifier[253] __initdata;
146 
147 /* Persistent data: */
148 
149 static int ic_proto_used;			/* Protocol used, if any */
150 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
151 static u8 ic_domain[64];		/* DNS (not NIS) domain name */
152 
153 /*
154  * Private state.
155  */
156 
157 /* Name of user-selected boot device */
158 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
159 
160 /* Protocols supported by available interfaces */
161 static int ic_proto_have_if __initdata = 0;
162 
163 #ifdef IPCONFIG_DYNAMIC
164 static DEFINE_SPINLOCK(ic_recv_lock);
165 static volatile int ic_got_reply __initdata = 0;    /* Proto(s) that replied */
166 #endif
167 #ifdef IPCONFIG_DHCP
168 static int ic_dhcp_msgtype __initdata = 0;	/* DHCP msg type received */
169 #endif
170 
171 
172 /*
173  *	Network devices
174  */
175 
176 struct ic_device {
177 	struct ic_device *next;
178 	struct net_device *dev;
179 	unsigned short flags;
180 	short able;
181 	__be32 xid;
182 };
183 
184 static struct ic_device *ic_first_dev __initdata = NULL;/* List of open device */
185 static struct net_device *ic_dev __initdata = NULL;	/* Selected device */
186 
187 static int __init ic_open_devs(void)
188 {
189 	struct ic_device *d, **last;
190 	struct net_device *dev;
191 	unsigned short oflags;
192 
193 	last = &ic_first_dev;
194 	rtnl_lock();
195 
196 	/* bring loopback device up first */
197 	for_each_netdev(&init_net, dev) {
198 		if (!(dev->flags & IFF_LOOPBACK))
199 			continue;
200 		if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
201 			printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
202 	}
203 
204 	for_each_netdev(&init_net, dev) {
205 		if (dev->flags & IFF_LOOPBACK)
206 			continue;
207 		if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
208 		    (!(dev->flags & IFF_LOOPBACK) &&
209 		     (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
210 		     strncmp(dev->name, "dummy", 5))) {
211 			int able = 0;
212 			if (dev->mtu >= 364)
213 				able |= IC_BOOTP;
214 			else
215 				printk(KERN_WARNING "DHCP/BOOTP: Ignoring device %s, MTU %d too small", dev->name, dev->mtu);
216 			if (!(dev->flags & IFF_NOARP))
217 				able |= IC_RARP;
218 			able &= ic_proto_enabled;
219 			if (ic_proto_enabled && !able)
220 				continue;
221 			oflags = dev->flags;
222 			if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
223 				printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
224 				continue;
225 			}
226 			if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
227 				rtnl_unlock();
228 				return -1;
229 			}
230 			d->dev = dev;
231 			*last = d;
232 			last = &d->next;
233 			d->flags = oflags;
234 			d->able = able;
235 			if (able & IC_BOOTP)
236 				get_random_bytes(&d->xid, sizeof(__be32));
237 			else
238 				d->xid = 0;
239 			ic_proto_have_if |= able;
240 			DBG(("IP-Config: %s UP (able=%d, xid=%08x)\n",
241 				dev->name, able, d->xid));
242 		}
243 	}
244 	rtnl_unlock();
245 
246 	*last = NULL;
247 
248 	if (!ic_first_dev) {
249 		if (user_dev_name[0])
250 			printk(KERN_ERR "IP-Config: Device `%s' not found.\n", user_dev_name);
251 		else
252 			printk(KERN_ERR "IP-Config: No network devices available.\n");
253 		return -1;
254 	}
255 	return 0;
256 }
257 
258 static void __init ic_close_devs(void)
259 {
260 	struct ic_device *d, *next;
261 	struct net_device *dev;
262 
263 	rtnl_lock();
264 	next = ic_first_dev;
265 	while ((d = next)) {
266 		next = d->next;
267 		dev = d->dev;
268 		if (dev != ic_dev) {
269 			DBG(("IP-Config: Downing %s\n", dev->name));
270 			dev_change_flags(dev, d->flags);
271 		}
272 		kfree(d);
273 	}
274 	rtnl_unlock();
275 }
276 
277 /*
278  *	Interface to various network functions.
279  */
280 
281 static inline void
282 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
283 {
284 	sin->sin_family = AF_INET;
285 	sin->sin_addr.s_addr = addr;
286 	sin->sin_port = port;
287 }
288 
289 static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
290 {
291 	int res;
292 
293 	mm_segment_t oldfs = get_fs();
294 	set_fs(get_ds());
295 	res = devinet_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
296 	set_fs(oldfs);
297 	return res;
298 }
299 
300 static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg)
301 {
302 	int res;
303 
304 	mm_segment_t oldfs = get_fs();
305 	set_fs(get_ds());
306 	res = ip_rt_ioctl(&init_net, cmd, (void __user *) arg);
307 	set_fs(oldfs);
308 	return res;
309 }
310 
311 /*
312  *	Set up interface addresses and routes.
313  */
314 
315 static int __init ic_setup_if(void)
316 {
317 	struct ifreq ir;
318 	struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
319 	int err;
320 
321 	memset(&ir, 0, sizeof(ir));
322 	strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->name);
323 	set_sockaddr(sin, ic_myaddr, 0);
324 	if ((err = ic_dev_ioctl(SIOCSIFADDR, &ir)) < 0) {
325 		printk(KERN_ERR "IP-Config: Unable to set interface address (%d).\n", err);
326 		return -1;
327 	}
328 	set_sockaddr(sin, ic_netmask, 0);
329 	if ((err = ic_dev_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
330 		printk(KERN_ERR "IP-Config: Unable to set interface netmask (%d).\n", err);
331 		return -1;
332 	}
333 	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
334 	if ((err = ic_dev_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
335 		printk(KERN_ERR "IP-Config: Unable to set interface broadcast address (%d).\n", err);
336 		return -1;
337 	}
338 	return 0;
339 }
340 
341 static int __init ic_setup_routes(void)
342 {
343 	/* No need to setup device routes, only the default route... */
344 
345 	if (ic_gateway != NONE) {
346 		struct rtentry rm;
347 		int err;
348 
349 		memset(&rm, 0, sizeof(rm));
350 		if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
351 			printk(KERN_ERR "IP-Config: Gateway not on directly connected network.\n");
352 			return -1;
353 		}
354 		set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
355 		set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
356 		set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
357 		rm.rt_flags = RTF_UP | RTF_GATEWAY;
358 		if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) {
359 			printk(KERN_ERR "IP-Config: Cannot add default route (%d).\n", err);
360 			return -1;
361 		}
362 	}
363 
364 	return 0;
365 }
366 
367 /*
368  *	Fill in default values for all missing parameters.
369  */
370 
371 static int __init ic_defaults(void)
372 {
373 	/*
374 	 *	At this point we have no userspace running so need not
375 	 *	claim locks on system_utsname
376 	 */
377 
378 	if (!ic_host_name_set)
379 		sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
380 
381 	if (root_server_addr == NONE)
382 		root_server_addr = ic_servaddr;
383 
384 	if (ic_netmask == NONE) {
385 		if (IN_CLASSA(ntohl(ic_myaddr)))
386 			ic_netmask = htonl(IN_CLASSA_NET);
387 		else if (IN_CLASSB(ntohl(ic_myaddr)))
388 			ic_netmask = htonl(IN_CLASSB_NET);
389 		else if (IN_CLASSC(ntohl(ic_myaddr)))
390 			ic_netmask = htonl(IN_CLASSC_NET);
391 		else {
392 			printk(KERN_ERR "IP-Config: Unable to guess netmask for address %pI4\n",
393 				&ic_myaddr);
394 			return -1;
395 		}
396 		printk("IP-Config: Guessing netmask %pI4\n", &ic_netmask);
397 	}
398 
399 	return 0;
400 }
401 
402 /*
403  *	RARP support.
404  */
405 
406 #ifdef IPCONFIG_RARP
407 
408 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
409 
410 static struct packet_type rarp_packet_type __initdata = {
411 	.type =	cpu_to_be16(ETH_P_RARP),
412 	.func =	ic_rarp_recv,
413 };
414 
415 static inline void __init ic_rarp_init(void)
416 {
417 	dev_add_pack(&rarp_packet_type);
418 }
419 
420 static inline void __init ic_rarp_cleanup(void)
421 {
422 	dev_remove_pack(&rarp_packet_type);
423 }
424 
425 /*
426  *  Process received RARP packet.
427  */
428 static int __init
429 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
430 {
431 	struct arphdr *rarp;
432 	unsigned char *rarp_ptr;
433 	__be32 sip, tip;
434 	unsigned char *sha, *tha;		/* s for "source", t for "target" */
435 	struct ic_device *d;
436 
437 	if (!net_eq(dev_net(dev), &init_net))
438 		goto drop;
439 
440 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
441 		return NET_RX_DROP;
442 
443 	if (!pskb_may_pull(skb, sizeof(struct arphdr)))
444 		goto drop;
445 
446 	/* Basic sanity checks can be done without the lock.  */
447 	rarp = (struct arphdr *)skb_transport_header(skb);
448 
449 	/* If this test doesn't pass, it's not IP, or we should
450 	 * ignore it anyway.
451 	 */
452 	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
453 		goto drop;
454 
455 	/* If it's not a RARP reply, delete it. */
456 	if (rarp->ar_op != htons(ARPOP_RREPLY))
457 		goto drop;
458 
459 	/* If it's not Ethernet, delete it. */
460 	if (rarp->ar_pro != htons(ETH_P_IP))
461 		goto drop;
462 
463 	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
464 		goto drop;
465 
466 	/* OK, it is all there and looks valid, process... */
467 	rarp = (struct arphdr *)skb_transport_header(skb);
468 	rarp_ptr = (unsigned char *) (rarp + 1);
469 
470 	/* One reply at a time, please. */
471 	spin_lock(&ic_recv_lock);
472 
473 	/* If we already have a reply, just drop the packet */
474 	if (ic_got_reply)
475 		goto drop_unlock;
476 
477 	/* Find the ic_device that the packet arrived on */
478 	d = ic_first_dev;
479 	while (d && d->dev != dev)
480 		d = d->next;
481 	if (!d)
482 		goto drop_unlock;	/* should never happen */
483 
484 	/* Extract variable-width fields */
485 	sha = rarp_ptr;
486 	rarp_ptr += dev->addr_len;
487 	memcpy(&sip, rarp_ptr, 4);
488 	rarp_ptr += 4;
489 	tha = rarp_ptr;
490 	rarp_ptr += dev->addr_len;
491 	memcpy(&tip, rarp_ptr, 4);
492 
493 	/* Discard packets which are not meant for us. */
494 	if (memcmp(tha, dev->dev_addr, dev->addr_len))
495 		goto drop_unlock;
496 
497 	/* Discard packets which are not from specified server. */
498 	if (ic_servaddr != NONE && ic_servaddr != sip)
499 		goto drop_unlock;
500 
501 	/* We have a winner! */
502 	ic_dev = dev;
503 	if (ic_myaddr == NONE)
504 		ic_myaddr = tip;
505 	ic_servaddr = sip;
506 	ic_got_reply = IC_RARP;
507 
508 drop_unlock:
509 	/* Show's over.  Nothing to see here.  */
510 	spin_unlock(&ic_recv_lock);
511 
512 drop:
513 	/* Throw the packet out. */
514 	kfree_skb(skb);
515 	return 0;
516 }
517 
518 
519 /*
520  *  Send RARP request packet over a single interface.
521  */
522 static void __init ic_rarp_send_if(struct ic_device *d)
523 {
524 	struct net_device *dev = d->dev;
525 	arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
526 		 dev->dev_addr, dev->dev_addr);
527 }
528 #endif
529 
530 /*
531  *	DHCP/BOOTP support.
532  */
533 
534 #ifdef IPCONFIG_BOOTP
535 
536 struct bootp_pkt {		/* BOOTP packet format */
537 	struct iphdr iph;	/* IP header */
538 	struct udphdr udph;	/* UDP header */
539 	u8 op;			/* 1=request, 2=reply */
540 	u8 htype;		/* HW address type */
541 	u8 hlen;		/* HW address length */
542 	u8 hops;		/* Used only by gateways */
543 	__be32 xid;		/* Transaction ID */
544 	__be16 secs;		/* Seconds since we started */
545 	__be16 flags;		/* Just what it says */
546 	__be32 client_ip;		/* Client's IP address if known */
547 	__be32 your_ip;		/* Assigned IP address */
548 	__be32 server_ip;		/* (Next, e.g. NFS) Server's IP address */
549 	__be32 relay_ip;		/* IP address of BOOTP relay */
550 	u8 hw_addr[16];		/* Client's HW address */
551 	u8 serv_name[64];	/* Server host name */
552 	u8 boot_file[128];	/* Name of boot file */
553 	u8 exten[312];		/* DHCP options / BOOTP vendor extensions */
554 };
555 
556 /* packet ops */
557 #define BOOTP_REQUEST	1
558 #define BOOTP_REPLY	2
559 
560 /* DHCP message types */
561 #define DHCPDISCOVER	1
562 #define DHCPOFFER	2
563 #define DHCPREQUEST	3
564 #define DHCPDECLINE	4
565 #define DHCPACK		5
566 #define DHCPNAK		6
567 #define DHCPRELEASE	7
568 #define DHCPINFORM	8
569 
570 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
571 
572 static struct packet_type bootp_packet_type __initdata = {
573 	.type =	cpu_to_be16(ETH_P_IP),
574 	.func =	ic_bootp_recv,
575 };
576 
577 
578 /*
579  *  Initialize DHCP/BOOTP extension fields in the request.
580  */
581 
582 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
583 
584 #ifdef IPCONFIG_DHCP
585 
586 static void __init
587 ic_dhcp_init_options(u8 *options)
588 {
589 	u8 mt = ((ic_servaddr == NONE)
590 		 ? DHCPDISCOVER : DHCPREQUEST);
591 	u8 *e = options;
592 	int len;
593 
594 #ifdef IPCONFIG_DEBUG
595 	printk("DHCP: Sending message type %d\n", mt);
596 #endif
597 
598 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
599 	e += 4;
600 
601 	*e++ = 53;		/* DHCP message type */
602 	*e++ = 1;
603 	*e++ = mt;
604 
605 	if (mt == DHCPREQUEST) {
606 		*e++ = 54;	/* Server ID (IP address) */
607 		*e++ = 4;
608 		memcpy(e, &ic_servaddr, 4);
609 		e += 4;
610 
611 		*e++ = 50;	/* Requested IP address */
612 		*e++ = 4;
613 		memcpy(e, &ic_myaddr, 4);
614 		e += 4;
615 	}
616 
617 	/* always? */
618 	{
619 		static const u8 ic_req_params[] = {
620 			1,	/* Subnet mask */
621 			3,	/* Default gateway */
622 			6,	/* DNS server */
623 			12,	/* Host name */
624 			15,	/* Domain name */
625 			17,	/* Boot path */
626 			40,	/* NIS domain name */
627 		};
628 
629 		*e++ = 55;	/* Parameter request list */
630 		*e++ = sizeof(ic_req_params);
631 		memcpy(e, ic_req_params, sizeof(ic_req_params));
632 		e += sizeof(ic_req_params);
633 
634 		if (*vendor_class_identifier) {
635 			printk(KERN_INFO "DHCP: sending class identifier \"%s\"\n",
636 			       vendor_class_identifier);
637 			*e++ = 60;	/* Class-identifier */
638 			len = strlen(vendor_class_identifier);
639 			*e++ = len;
640 			memcpy(e, vendor_class_identifier, len);
641 			e += len;
642 		}
643 	}
644 
645 	*e++ = 255;	/* End of the list */
646 }
647 
648 #endif /* IPCONFIG_DHCP */
649 
650 static void __init ic_bootp_init_ext(u8 *e)
651 {
652 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
653 	e += 4;
654 	*e++ = 1;		/* Subnet mask request */
655 	*e++ = 4;
656 	e += 4;
657 	*e++ = 3;		/* Default gateway request */
658 	*e++ = 4;
659 	e += 4;
660 	*e++ = 5;		/* Name server request */
661 	*e++ = 8;
662 	e += 8;
663 	*e++ = 12;		/* Host name request */
664 	*e++ = 32;
665 	e += 32;
666 	*e++ = 40;		/* NIS Domain name request */
667 	*e++ = 32;
668 	e += 32;
669 	*e++ = 17;		/* Boot path */
670 	*e++ = 40;
671 	e += 40;
672 
673 	*e++ = 57;		/* set extension buffer size for reply */
674 	*e++ = 2;
675 	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
676 	*e++ = 150;
677 
678 	*e++ = 255;		/* End of the list */
679 }
680 
681 
682 /*
683  *  Initialize the DHCP/BOOTP mechanism.
684  */
685 static inline void __init ic_bootp_init(void)
686 {
687 	int i;
688 
689 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
690 		ic_nameservers[i] = NONE;
691 
692 	dev_add_pack(&bootp_packet_type);
693 }
694 
695 
696 /*
697  *  DHCP/BOOTP cleanup.
698  */
699 static inline void __init ic_bootp_cleanup(void)
700 {
701 	dev_remove_pack(&bootp_packet_type);
702 }
703 
704 
705 /*
706  *  Send DHCP/BOOTP request to single interface.
707  */
708 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
709 {
710 	struct net_device *dev = d->dev;
711 	struct sk_buff *skb;
712 	struct bootp_pkt *b;
713 	struct iphdr *h;
714 
715 	/* Allocate packet */
716 	skb = alloc_skb(sizeof(struct bootp_pkt) + LL_ALLOCATED_SPACE(dev) + 15,
717 			GFP_KERNEL);
718 	if (!skb)
719 		return;
720 	skb_reserve(skb, LL_RESERVED_SPACE(dev));
721 	b = (struct bootp_pkt *) skb_put(skb, sizeof(struct bootp_pkt));
722 	memset(b, 0, sizeof(struct bootp_pkt));
723 
724 	/* Construct IP header */
725 	skb_reset_network_header(skb);
726 	h = ip_hdr(skb);
727 	h->version = 4;
728 	h->ihl = 5;
729 	h->tot_len = htons(sizeof(struct bootp_pkt));
730 	h->frag_off = htons(IP_DF);
731 	h->ttl = 64;
732 	h->protocol = IPPROTO_UDP;
733 	h->daddr = htonl(INADDR_BROADCAST);
734 	h->check = ip_fast_csum((unsigned char *) h, h->ihl);
735 
736 	/* Construct UDP header */
737 	b->udph.source = htons(68);
738 	b->udph.dest = htons(67);
739 	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
740 	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
741 
742 	/* Construct DHCP/BOOTP header */
743 	b->op = BOOTP_REQUEST;
744 	if (dev->type < 256) /* check for false types */
745 		b->htype = dev->type;
746 	else if (dev->type == ARPHRD_IEEE802_TR) /* fix for token ring */
747 		b->htype = ARPHRD_IEEE802;
748 	else if (dev->type == ARPHRD_FDDI)
749 		b->htype = ARPHRD_ETHER;
750 	else {
751 		printk("Unknown ARP type 0x%04x for device %s\n", dev->type, dev->name);
752 		b->htype = dev->type; /* can cause undefined behavior */
753 	}
754 
755 	/* server_ip and your_ip address are both already zero per RFC2131 */
756 	b->hlen = dev->addr_len;
757 	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
758 	b->secs = htons(jiffies_diff / HZ);
759 	b->xid = d->xid;
760 
761 	/* add DHCP options or BOOTP extensions */
762 #ifdef IPCONFIG_DHCP
763 	if (ic_proto_enabled & IC_USE_DHCP)
764 		ic_dhcp_init_options(b->exten);
765 	else
766 #endif
767 		ic_bootp_init_ext(b->exten);
768 
769 	/* Chain packet down the line... */
770 	skb->dev = dev;
771 	skb->protocol = htons(ETH_P_IP);
772 	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
773 			    dev->broadcast, dev->dev_addr, skb->len) < 0 ||
774 	    dev_queue_xmit(skb) < 0)
775 		printk("E");
776 }
777 
778 
779 /*
780  *  Copy BOOTP-supplied string if not already set.
781  */
782 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
783 {
784 	if (!len)
785 		return 0;
786 	if (len > max-1)
787 		len = max-1;
788 	memcpy(dest, src, len);
789 	dest[len] = '\0';
790 	return 1;
791 }
792 
793 
794 /*
795  *  Process BOOTP extensions.
796  */
797 static void __init ic_do_bootp_ext(u8 *ext)
798 {
799        u8 servers;
800        int i;
801 
802 #ifdef IPCONFIG_DEBUG
803 	u8 *c;
804 
805 	printk("DHCP/BOOTP: Got extension %d:",*ext);
806 	for (c=ext+2; c<ext+2+ext[1]; c++)
807 		printk(" %02x", *c);
808 	printk("\n");
809 #endif
810 
811 	switch (*ext++) {
812 		case 1:		/* Subnet mask */
813 			if (ic_netmask == NONE)
814 				memcpy(&ic_netmask, ext+1, 4);
815 			break;
816 		case 3:		/* Default gateway */
817 			if (ic_gateway == NONE)
818 				memcpy(&ic_gateway, ext+1, 4);
819 			break;
820 		case 6:		/* DNS server */
821 			servers= *ext/4;
822 			if (servers > CONF_NAMESERVERS_MAX)
823 				servers = CONF_NAMESERVERS_MAX;
824 			for (i = 0; i < servers; i++) {
825 				if (ic_nameservers[i] == NONE)
826 					memcpy(&ic_nameservers[i], ext+1+4*i, 4);
827 			}
828 			break;
829 		case 12:	/* Host name */
830 			ic_bootp_string(utsname()->nodename, ext+1, *ext, __NEW_UTS_LEN);
831 			ic_host_name_set = 1;
832 			break;
833 		case 15:	/* Domain name (DNS) */
834 			ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
835 			break;
836 		case 17:	/* Root path */
837 			if (!root_server_path[0])
838 				ic_bootp_string(root_server_path, ext+1, *ext, sizeof(root_server_path));
839 			break;
840 		case 40:	/* NIS Domain name (_not_ DNS) */
841 			ic_bootp_string(utsname()->domainname, ext+1, *ext, __NEW_UTS_LEN);
842 			break;
843 	}
844 }
845 
846 
847 /*
848  *  Receive BOOTP reply.
849  */
850 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
851 {
852 	struct bootp_pkt *b;
853 	struct iphdr *h;
854 	struct ic_device *d;
855 	int len, ext_len;
856 
857 	if (!net_eq(dev_net(dev), &init_net))
858 		goto drop;
859 
860 	/* Perform verifications before taking the lock.  */
861 	if (skb->pkt_type == PACKET_OTHERHOST)
862 		goto drop;
863 
864 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
865 		return NET_RX_DROP;
866 
867 	if (!pskb_may_pull(skb,
868 			   sizeof(struct iphdr) +
869 			   sizeof(struct udphdr)))
870 		goto drop;
871 
872 	b = (struct bootp_pkt *)skb_network_header(skb);
873 	h = &b->iph;
874 
875 	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
876 		goto drop;
877 
878 	/* Fragments are not supported */
879 	if (h->frag_off & htons(IP_OFFSET | IP_MF)) {
880 		if (net_ratelimit())
881 			printk(KERN_ERR "DHCP/BOOTP: Ignoring fragmented "
882 			       "reply.\n");
883 		goto drop;
884 	}
885 
886 	if (skb->len < ntohs(h->tot_len))
887 		goto drop;
888 
889 	if (ip_fast_csum((char *) h, h->ihl))
890 		goto drop;
891 
892 	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
893 		goto drop;
894 
895 	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
896 		goto drop;
897 
898 	len = ntohs(b->udph.len) - sizeof(struct udphdr);
899 	ext_len = len - (sizeof(*b) -
900 			 sizeof(struct iphdr) -
901 			 sizeof(struct udphdr) -
902 			 sizeof(b->exten));
903 	if (ext_len < 0)
904 		goto drop;
905 
906 	/* Ok the front looks good, make sure we can get at the rest.  */
907 	if (!pskb_may_pull(skb, skb->len))
908 		goto drop;
909 
910 	b = (struct bootp_pkt *)skb_network_header(skb);
911 	h = &b->iph;
912 
913 	/* One reply at a time, please. */
914 	spin_lock(&ic_recv_lock);
915 
916 	/* If we already have a reply, just drop the packet */
917 	if (ic_got_reply)
918 		goto drop_unlock;
919 
920 	/* Find the ic_device that the packet arrived on */
921 	d = ic_first_dev;
922 	while (d && d->dev != dev)
923 		d = d->next;
924 	if (!d)
925 		goto drop_unlock;  /* should never happen */
926 
927 	/* Is it a reply to our BOOTP request? */
928 	if (b->op != BOOTP_REPLY ||
929 	    b->xid != d->xid) {
930 		if (net_ratelimit())
931 			printk(KERN_ERR "DHCP/BOOTP: Reply not for us, "
932 			       "op[%x] xid[%x]\n",
933 			       b->op, b->xid);
934 		goto drop_unlock;
935 	}
936 
937 	/* Is it a reply for the device we are configuring? */
938 	if (b->xid != ic_dev_xid) {
939 		if (net_ratelimit())
940 			printk(KERN_ERR "DHCP/BOOTP: Ignoring delayed packet \n");
941 		goto drop_unlock;
942 	}
943 
944 	/* Parse extensions */
945 	if (ext_len >= 4 &&
946 	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
947 		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
948 		u8 *ext;
949 
950 #ifdef IPCONFIG_DHCP
951 		if (ic_proto_enabled & IC_USE_DHCP) {
952 			__be32 server_id = NONE;
953 			int mt = 0;
954 
955 			ext = &b->exten[4];
956 			while (ext < end && *ext != 0xff) {
957 				u8 *opt = ext++;
958 				if (*opt == 0)	/* Padding */
959 					continue;
960 				ext += *ext + 1;
961 				if (ext >= end)
962 					break;
963 				switch (*opt) {
964 				case 53:	/* Message type */
965 					if (opt[1])
966 						mt = opt[2];
967 					break;
968 				case 54:	/* Server ID (IP address) */
969 					if (opt[1] >= 4)
970 						memcpy(&server_id, opt + 2, 4);
971 					break;
972 				}
973 			}
974 
975 #ifdef IPCONFIG_DEBUG
976 			printk("DHCP: Got message type %d\n", mt);
977 #endif
978 
979 			switch (mt) {
980 			case DHCPOFFER:
981 				/* While in the process of accepting one offer,
982 				 * ignore all others.
983 				 */
984 				if (ic_myaddr != NONE)
985 					goto drop_unlock;
986 
987 				/* Let's accept that offer. */
988 				ic_myaddr = b->your_ip;
989 				ic_servaddr = server_id;
990 #ifdef IPCONFIG_DEBUG
991 				printk("DHCP: Offered address %pI4 by server %pI4\n",
992 				       &ic_myaddr, &ic_servaddr);
993 #endif
994 				/* The DHCP indicated server address takes
995 				 * precedence over the bootp header one if
996 				 * they are different.
997 				 */
998 				if ((server_id != NONE) &&
999 				    (b->server_ip != server_id))
1000 					b->server_ip = ic_servaddr;
1001 				break;
1002 
1003 			case DHCPACK:
1004 				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1005 					goto drop_unlock;
1006 
1007 				/* Yeah! */
1008 				break;
1009 
1010 			default:
1011 				/* Urque.  Forget it*/
1012 				ic_myaddr = NONE;
1013 				ic_servaddr = NONE;
1014 				goto drop_unlock;
1015 			}
1016 
1017 			ic_dhcp_msgtype = mt;
1018 
1019 		}
1020 #endif /* IPCONFIG_DHCP */
1021 
1022 		ext = &b->exten[4];
1023 		while (ext < end && *ext != 0xff) {
1024 			u8 *opt = ext++;
1025 			if (*opt == 0)	/* Padding */
1026 				continue;
1027 			ext += *ext + 1;
1028 			if (ext < end)
1029 				ic_do_bootp_ext(opt);
1030 		}
1031 	}
1032 
1033 	/* We have a winner! */
1034 	ic_dev = dev;
1035 	ic_myaddr = b->your_ip;
1036 	ic_servaddr = b->server_ip;
1037 	if (ic_gateway == NONE && b->relay_ip)
1038 		ic_gateway = b->relay_ip;
1039 	if (ic_nameservers[0] == NONE)
1040 		ic_nameservers[0] = ic_servaddr;
1041 	ic_got_reply = IC_BOOTP;
1042 
1043 drop_unlock:
1044 	/* Show's over.  Nothing to see here.  */
1045 	spin_unlock(&ic_recv_lock);
1046 
1047 drop:
1048 	/* Throw the packet out. */
1049 	kfree_skb(skb);
1050 
1051 	return 0;
1052 }
1053 
1054 
1055 #endif
1056 
1057 
1058 /*
1059  *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
1060  */
1061 
1062 #ifdef IPCONFIG_DYNAMIC
1063 
1064 static int __init ic_dynamic(void)
1065 {
1066 	int retries;
1067 	struct ic_device *d;
1068 	unsigned long start_jiffies, timeout, jiff;
1069 	int do_bootp = ic_proto_have_if & IC_BOOTP;
1070 	int do_rarp = ic_proto_have_if & IC_RARP;
1071 
1072 	/*
1073 	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1074 	 * This routine gets only called when some pieces of information
1075 	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1076 	 */
1077 	if (!ic_proto_enabled) {
1078 		printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
1079 		return -1;
1080 	}
1081 
1082 #ifdef IPCONFIG_BOOTP
1083 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1084 		printk(KERN_ERR "DHCP/BOOTP: No suitable device found.\n");
1085 #endif
1086 #ifdef IPCONFIG_RARP
1087 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1088 		printk(KERN_ERR "RARP: No suitable device found.\n");
1089 #endif
1090 
1091 	if (!ic_proto_have_if)
1092 		/* Error message already printed */
1093 		return -1;
1094 
1095 	/*
1096 	 * Setup protocols
1097 	 */
1098 #ifdef IPCONFIG_BOOTP
1099 	if (do_bootp)
1100 		ic_bootp_init();
1101 #endif
1102 #ifdef IPCONFIG_RARP
1103 	if (do_rarp)
1104 		ic_rarp_init();
1105 #endif
1106 
1107 	/*
1108 	 * Send requests and wait, until we get an answer. This loop
1109 	 * seems to be a terrible waste of CPU time, but actually there is
1110 	 * only one process running at all, so we don't need to use any
1111 	 * scheduler functions.
1112 	 * [Actually we could now, but the nothing else running note still
1113 	 *  applies.. - AC]
1114 	 */
1115 	printk(KERN_NOTICE "Sending %s%s%s requests .",
1116 	       do_bootp
1117 		? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1118 	       (do_bootp && do_rarp) ? " and " : "",
1119 	       do_rarp ? "RARP" : "");
1120 
1121 	start_jiffies = jiffies;
1122 	d = ic_first_dev;
1123 	retries = CONF_SEND_RETRIES;
1124 	get_random_bytes(&timeout, sizeof(timeout));
1125 	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned) CONF_TIMEOUT_RANDOM);
1126 	for (;;) {
1127 		/* Track the device we are configuring */
1128 		ic_dev_xid = d->xid;
1129 
1130 #ifdef IPCONFIG_BOOTP
1131 		if (do_bootp && (d->able & IC_BOOTP))
1132 			ic_bootp_send_if(d, jiffies - start_jiffies);
1133 #endif
1134 #ifdef IPCONFIG_RARP
1135 		if (do_rarp && (d->able & IC_RARP))
1136 			ic_rarp_send_if(d);
1137 #endif
1138 
1139 		jiff = jiffies + (d->next ? CONF_INTER_TIMEOUT : timeout);
1140 		while (time_before(jiffies, jiff) && !ic_got_reply)
1141 			schedule_timeout_uninterruptible(1);
1142 #ifdef IPCONFIG_DHCP
1143 		/* DHCP isn't done until we get a DHCPACK. */
1144 		if ((ic_got_reply & IC_BOOTP)
1145 		    && (ic_proto_enabled & IC_USE_DHCP)
1146 		    && ic_dhcp_msgtype != DHCPACK)
1147 		{
1148 			ic_got_reply = 0;
1149 			printk(",");
1150 			continue;
1151 		}
1152 #endif /* IPCONFIG_DHCP */
1153 
1154 		if (ic_got_reply) {
1155 			printk(" OK\n");
1156 			break;
1157 		}
1158 
1159 		if ((d = d->next))
1160 			continue;
1161 
1162 		if (! --retries) {
1163 			printk(" timed out!\n");
1164 			break;
1165 		}
1166 
1167 		d = ic_first_dev;
1168 
1169 		timeout = timeout CONF_TIMEOUT_MULT;
1170 		if (timeout > CONF_TIMEOUT_MAX)
1171 			timeout = CONF_TIMEOUT_MAX;
1172 
1173 		printk(".");
1174 	}
1175 
1176 #ifdef IPCONFIG_BOOTP
1177 	if (do_bootp)
1178 		ic_bootp_cleanup();
1179 #endif
1180 #ifdef IPCONFIG_RARP
1181 	if (do_rarp)
1182 		ic_rarp_cleanup();
1183 #endif
1184 
1185 	if (!ic_got_reply) {
1186 		ic_myaddr = NONE;
1187 		return -1;
1188 	}
1189 
1190 	printk("IP-Config: Got %s answer from %pI4, ",
1191 		((ic_got_reply & IC_RARP) ? "RARP"
1192 		 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1193 		&ic_servaddr);
1194 	printk("my address is %pI4\n", &ic_myaddr);
1195 
1196 	return 0;
1197 }
1198 
1199 #endif /* IPCONFIG_DYNAMIC */
1200 
1201 #ifdef CONFIG_PROC_FS
1202 
1203 static int pnp_seq_show(struct seq_file *seq, void *v)
1204 {
1205 	int i;
1206 
1207 	if (ic_proto_used & IC_PROTO)
1208 		seq_printf(seq, "#PROTO: %s\n",
1209 			   (ic_proto_used & IC_RARP) ? "RARP"
1210 			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1211 	else
1212 		seq_puts(seq, "#MANUAL\n");
1213 
1214 	if (ic_domain[0])
1215 		seq_printf(seq,
1216 			   "domain %s\n", ic_domain);
1217 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1218 		if (ic_nameservers[i] != NONE)
1219 			seq_printf(seq, "nameserver %pI4\n",
1220 				   &ic_nameservers[i]);
1221 	}
1222 	if (ic_servaddr != NONE)
1223 		seq_printf(seq, "bootserver %pI4\n",
1224 			   &ic_servaddr);
1225 	return 0;
1226 }
1227 
1228 static int pnp_seq_open(struct inode *indoe, struct file *file)
1229 {
1230 	return single_open(file, pnp_seq_show, NULL);
1231 }
1232 
1233 static const struct file_operations pnp_seq_fops = {
1234 	.owner		= THIS_MODULE,
1235 	.open		= pnp_seq_open,
1236 	.read		= seq_read,
1237 	.llseek		= seq_lseek,
1238 	.release	= single_release,
1239 };
1240 #endif /* CONFIG_PROC_FS */
1241 
1242 /*
1243  *  Extract IP address from the parameter string if needed. Note that we
1244  *  need to have root_server_addr set _before_ IPConfig gets called as it
1245  *  can override it.
1246  */
1247 __be32 __init root_nfs_parse_addr(char *name)
1248 {
1249 	__be32 addr;
1250 	int octets = 0;
1251 	char *cp, *cq;
1252 
1253 	cp = cq = name;
1254 	while (octets < 4) {
1255 		while (*cp >= '0' && *cp <= '9')
1256 			cp++;
1257 		if (cp == cq || cp - cq > 3)
1258 			break;
1259 		if (*cp == '.' || octets == 3)
1260 			octets++;
1261 		if (octets < 4)
1262 			cp++;
1263 		cq = cp;
1264 	}
1265 	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1266 		if (*cp == ':')
1267 			*cp++ = '\0';
1268 		addr = in_aton(name);
1269 		memmove(name, cp, strlen(cp) + 1);
1270 	} else
1271 		addr = NONE;
1272 
1273 	return addr;
1274 }
1275 
1276 /*
1277  *	IP Autoconfig dispatcher.
1278  */
1279 
1280 static int __init ip_auto_config(void)
1281 {
1282 	__be32 addr;
1283 #ifdef IPCONFIG_DYNAMIC
1284 	int retries = CONF_OPEN_RETRIES;
1285 #endif
1286 
1287 #ifdef CONFIG_PROC_FS
1288 	proc_net_fops_create(&init_net, "pnp", S_IRUGO, &pnp_seq_fops);
1289 #endif /* CONFIG_PROC_FS */
1290 
1291 	if (!ic_enable)
1292 		return 0;
1293 
1294 	DBG(("IP-Config: Entered.\n"));
1295 #ifdef IPCONFIG_DYNAMIC
1296  try_try_again:
1297 #endif
1298 	/* Give hardware a chance to settle */
1299 	msleep(CONF_PRE_OPEN);
1300 
1301 	/* Setup all network devices */
1302 	if (ic_open_devs() < 0)
1303 		return -1;
1304 
1305 	/* Give drivers a chance to settle */
1306 	ssleep(CONF_POST_OPEN);
1307 
1308 	/*
1309 	 * If the config information is insufficient (e.g., our IP address or
1310 	 * IP address of the boot server is missing or we have multiple network
1311 	 * interfaces and no default was set), use BOOTP or RARP to get the
1312 	 * missing values.
1313 	 */
1314 	if (ic_myaddr == NONE ||
1315 #ifdef CONFIG_ROOT_NFS
1316 	    (root_server_addr == NONE
1317 	     && ic_servaddr == NONE
1318 	     && ROOT_DEV == Root_NFS) ||
1319 #endif
1320 	    ic_first_dev->next) {
1321 #ifdef IPCONFIG_DYNAMIC
1322 		if (ic_dynamic() < 0) {
1323 			ic_close_devs();
1324 
1325 			/*
1326 			 * I don't know why, but sometimes the
1327 			 * eepro100 driver (at least) gets upset and
1328 			 * doesn't work the first time it's opened.
1329 			 * But then if you close it and reopen it, it
1330 			 * works just fine.  So we need to try that at
1331 			 * least once before giving up.
1332 			 *
1333 			 * Also, if the root will be NFS-mounted, we
1334 			 * have nowhere to go if DHCP fails.  So we
1335 			 * just have to keep trying forever.
1336 			 *
1337 			 * 				-- Chip
1338 			 */
1339 #ifdef CONFIG_ROOT_NFS
1340 			if (ROOT_DEV ==  Root_NFS) {
1341 				printk(KERN_ERR
1342 					"IP-Config: Retrying forever (NFS root)...\n");
1343 				goto try_try_again;
1344 			}
1345 #endif
1346 
1347 			if (--retries) {
1348 				printk(KERN_ERR
1349 				       "IP-Config: Reopening network devices...\n");
1350 				goto try_try_again;
1351 			}
1352 
1353 			/* Oh, well.  At least we tried. */
1354 			printk(KERN_ERR "IP-Config: Auto-configuration of network failed.\n");
1355 			return -1;
1356 		}
1357 #else /* !DYNAMIC */
1358 		printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
1359 		ic_close_devs();
1360 		return -1;
1361 #endif /* IPCONFIG_DYNAMIC */
1362 	} else {
1363 		/* Device selected manually or only one device -> use it */
1364 		ic_dev = ic_first_dev->dev;
1365 	}
1366 
1367 	addr = root_nfs_parse_addr(root_server_path);
1368 	if (root_server_addr == NONE)
1369 		root_server_addr = addr;
1370 
1371 	/*
1372 	 * Use defaults whereever applicable.
1373 	 */
1374 	if (ic_defaults() < 0)
1375 		return -1;
1376 
1377 	/*
1378 	 * Close all network devices except the device we've
1379 	 * autoconfigured and set up routes.
1380 	 */
1381 	ic_close_devs();
1382 	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1383 		return -1;
1384 
1385 	/*
1386 	 * Record which protocol was actually used.
1387 	 */
1388 #ifdef IPCONFIG_DYNAMIC
1389 	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1390 #endif
1391 
1392 #ifndef IPCONFIG_SILENT
1393 	/*
1394 	 * Clue in the operator.
1395 	 */
1396 	printk("IP-Config: Complete:");
1397 	printk("\n     device=%s", ic_dev->name);
1398 	printk(", addr=%pI4", &ic_myaddr);
1399 	printk(", mask=%pI4", &ic_netmask);
1400 	printk(", gw=%pI4", &ic_gateway);
1401 	printk(",\n     host=%s, domain=%s, nis-domain=%s",
1402 	       utsname()->nodename, ic_domain, utsname()->domainname);
1403 	printk(",\n     bootserver=%pI4", &ic_servaddr);
1404 	printk(", rootserver=%pI4", &root_server_addr);
1405 	printk(", rootpath=%s", root_server_path);
1406 	printk("\n");
1407 #endif /* !SILENT */
1408 
1409 	return 0;
1410 }
1411 
1412 late_initcall(ip_auto_config);
1413 
1414 
1415 /*
1416  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1417  *  command line parameter.  See Documentation/filesystems/nfsroot.txt.
1418  */
1419 static int __init ic_proto_name(char *name)
1420 {
1421 	if (!strcmp(name, "on") || !strcmp(name, "any")) {
1422 		return 1;
1423 	}
1424 	if (!strcmp(name, "off") || !strcmp(name, "none")) {
1425 		return 0;
1426 	}
1427 #ifdef CONFIG_IP_PNP_DHCP
1428 	else if (!strcmp(name, "dhcp")) {
1429 		ic_proto_enabled &= ~IC_RARP;
1430 		return 1;
1431 	}
1432 #endif
1433 #ifdef CONFIG_IP_PNP_BOOTP
1434 	else if (!strcmp(name, "bootp")) {
1435 		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1436 		return 1;
1437 	}
1438 #endif
1439 #ifdef CONFIG_IP_PNP_RARP
1440 	else if (!strcmp(name, "rarp")) {
1441 		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1442 		return 1;
1443 	}
1444 #endif
1445 #ifdef IPCONFIG_DYNAMIC
1446 	else if (!strcmp(name, "both")) {
1447 		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1448 		return 1;
1449 	}
1450 #endif
1451 	return 0;
1452 }
1453 
1454 static int __init ip_auto_config_setup(char *addrs)
1455 {
1456 	char *cp, *ip, *dp;
1457 	int num = 0;
1458 
1459 	ic_set_manually = 1;
1460 	ic_enable = 1;
1461 
1462 	/*
1463 	 * If any dhcp, bootp etc options are set, leave autoconfig on
1464 	 * and skip the below static IP processing.
1465 	 */
1466 	if (ic_proto_name(addrs))
1467 		return 1;
1468 
1469 	/* If no static IP is given, turn off autoconfig and bail.  */
1470 	if (*addrs == 0 ||
1471 	    strcmp(addrs, "off") == 0 ||
1472 	    strcmp(addrs, "none") == 0) {
1473 		ic_enable = 0;
1474 		return 1;
1475 	}
1476 
1477 	/* Parse string for static IP assignment.  */
1478 	ip = addrs;
1479 	while (ip && *ip) {
1480 		if ((cp = strchr(ip, ':')))
1481 			*cp++ = '\0';
1482 		if (strlen(ip) > 0) {
1483 			DBG(("IP-Config: Parameter #%d: `%s'\n", num, ip));
1484 			switch (num) {
1485 			case 0:
1486 				if ((ic_myaddr = in_aton(ip)) == ANY)
1487 					ic_myaddr = NONE;
1488 				break;
1489 			case 1:
1490 				if ((ic_servaddr = in_aton(ip)) == ANY)
1491 					ic_servaddr = NONE;
1492 				break;
1493 			case 2:
1494 				if ((ic_gateway = in_aton(ip)) == ANY)
1495 					ic_gateway = NONE;
1496 				break;
1497 			case 3:
1498 				if ((ic_netmask = in_aton(ip)) == ANY)
1499 					ic_netmask = NONE;
1500 				break;
1501 			case 4:
1502 				if ((dp = strchr(ip, '.'))) {
1503 					*dp++ = '\0';
1504 					strlcpy(utsname()->domainname, dp,
1505 						sizeof(utsname()->domainname));
1506 				}
1507 				strlcpy(utsname()->nodename, ip,
1508 					sizeof(utsname()->nodename));
1509 				ic_host_name_set = 1;
1510 				break;
1511 			case 5:
1512 				strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1513 				break;
1514 			case 6:
1515 				if (ic_proto_name(ip) == 0 &&
1516 				    ic_myaddr == NONE) {
1517 					ic_enable = 0;
1518 				}
1519 				break;
1520 			}
1521 		}
1522 		ip = cp;
1523 		num++;
1524 	}
1525 
1526 	return 1;
1527 }
1528 
1529 static int __init nfsaddrs_config_setup(char *addrs)
1530 {
1531 	return ip_auto_config_setup(addrs);
1532 }
1533 
1534 static int __init vendor_class_identifier_setup(char *addrs)
1535 {
1536 	if (strlcpy(vendor_class_identifier, addrs,
1537 		    sizeof(vendor_class_identifier))
1538 	    >= sizeof(vendor_class_identifier))
1539 		printk(KERN_WARNING "DHCP: vendorclass too long, truncated to \"%s\"",
1540 		       vendor_class_identifier);
1541 	return 1;
1542 }
1543 
1544 __setup("ip=", ip_auto_config_setup);
1545 __setup("nfsaddrs=", nfsaddrs_config_setup);
1546 __setup("dhcpclass=", vendor_class_identifier_setup);
1547