xref: /linux/net/ipv4/ipconfig.c (revision a33f32244d8550da8b4a26e277ce07d5c6d158b5)
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 <linux/slab.h>
57 #include <net/net_namespace.h>
58 #include <net/arp.h>
59 #include <net/ip.h>
60 #include <net/ipconfig.h>
61 #include <net/route.h>
62 
63 #include <asm/uaccess.h>
64 #include <net/checksum.h>
65 #include <asm/processor.h>
66 
67 /* Define this to allow debugging output */
68 #undef IPCONFIG_DEBUG
69 
70 #ifdef IPCONFIG_DEBUG
71 #define DBG(x) printk x
72 #else
73 #define DBG(x) do { } while(0)
74 #endif
75 
76 #if defined(CONFIG_IP_PNP_DHCP)
77 #define IPCONFIG_DHCP
78 #endif
79 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
80 #define IPCONFIG_BOOTP
81 #endif
82 #if defined(CONFIG_IP_PNP_RARP)
83 #define IPCONFIG_RARP
84 #endif
85 #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
86 #define IPCONFIG_DYNAMIC
87 #endif
88 
89 /* Define the friendly delay before and after opening net devices */
90 #define CONF_PRE_OPEN		500	/* Before opening: 1/2 second */
91 #define CONF_POST_OPEN		1	/* After opening: 1 second */
92 
93 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
94 #define CONF_OPEN_RETRIES 	2	/* (Re)open devices twice */
95 #define CONF_SEND_RETRIES 	6	/* Send six requests per open */
96 #define CONF_INTER_TIMEOUT	(HZ/2)	/* Inter-device timeout: 1/2 second */
97 #define CONF_BASE_TIMEOUT	(HZ*2)	/* Initial timeout: 2 seconds */
98 #define CONF_TIMEOUT_RANDOM	(HZ)	/* Maximum amount of randomization */
99 #define CONF_TIMEOUT_MULT	*7/4	/* Rate of timeout growth */
100 #define CONF_TIMEOUT_MAX	(HZ*30)	/* Maximum allowed timeout */
101 #define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
102 					   - '3' from resolv.h */
103 
104 #define NONE cpu_to_be32(INADDR_NONE)
105 #define ANY cpu_to_be32(INADDR_ANY)
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 u32 ic_dev_xid;		/* Device under configuration */
144 
145 /* vendor class identifier */
146 static char vendor_class_identifier[253] __initdata;
147 
148 /* Persistent data: */
149 
150 static int ic_proto_used;			/* Protocol used, if any */
151 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
152 static u8 ic_domain[64];		/* DNS (not NIS) domain name */
153 
154 /*
155  * Private state.
156  */
157 
158 /* Name of user-selected boot device */
159 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
160 
161 /* Protocols supported by available interfaces */
162 static int ic_proto_have_if __initdata = 0;
163 
164 /* MTU for boot device */
165 static int ic_dev_mtu __initdata = 0;
166 
167 #ifdef IPCONFIG_DYNAMIC
168 static DEFINE_SPINLOCK(ic_recv_lock);
169 static volatile int ic_got_reply __initdata = 0;    /* Proto(s) that replied */
170 #endif
171 #ifdef IPCONFIG_DHCP
172 static int ic_dhcp_msgtype __initdata = 0;	/* DHCP msg type received */
173 #endif
174 
175 
176 /*
177  *	Network devices
178  */
179 
180 struct ic_device {
181 	struct ic_device *next;
182 	struct net_device *dev;
183 	unsigned short flags;
184 	short able;
185 	__be32 xid;
186 };
187 
188 static struct ic_device *ic_first_dev __initdata = NULL;/* List of open device */
189 static struct net_device *ic_dev __initdata = NULL;	/* Selected device */
190 
191 static bool __init ic_device_match(struct net_device *dev)
192 {
193 	if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
194 	    (!(dev->flags & IFF_LOOPBACK) &&
195 	     (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
196 	     strncmp(dev->name, "dummy", 5)))
197 		return true;
198 	return false;
199 }
200 
201 static int __init ic_open_devs(void)
202 {
203 	struct ic_device *d, **last;
204 	struct net_device *dev;
205 	unsigned short oflags;
206 
207 	last = &ic_first_dev;
208 	rtnl_lock();
209 
210 	/* bring loopback device up first */
211 	for_each_netdev(&init_net, dev) {
212 		if (!(dev->flags & IFF_LOOPBACK))
213 			continue;
214 		if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
215 			printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
216 	}
217 
218 	for_each_netdev(&init_net, dev) {
219 		if (dev->flags & IFF_LOOPBACK)
220 			continue;
221 		if (ic_device_match(dev)) {
222 			int able = 0;
223 			if (dev->mtu >= 364)
224 				able |= IC_BOOTP;
225 			else
226 				printk(KERN_WARNING "DHCP/BOOTP: Ignoring device %s, MTU %d too small", dev->name, dev->mtu);
227 			if (!(dev->flags & IFF_NOARP))
228 				able |= IC_RARP;
229 			able &= ic_proto_enabled;
230 			if (ic_proto_enabled && !able)
231 				continue;
232 			oflags = dev->flags;
233 			if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
234 				printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
235 				continue;
236 			}
237 			if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
238 				rtnl_unlock();
239 				return -ENOMEM;
240 			}
241 			d->dev = dev;
242 			*last = d;
243 			last = &d->next;
244 			d->flags = oflags;
245 			d->able = able;
246 			if (able & IC_BOOTP)
247 				get_random_bytes(&d->xid, sizeof(__be32));
248 			else
249 				d->xid = 0;
250 			ic_proto_have_if |= able;
251 			DBG(("IP-Config: %s UP (able=%d, xid=%08x)\n",
252 				dev->name, able, d->xid));
253 		}
254 	}
255 	rtnl_unlock();
256 
257 	*last = NULL;
258 
259 	if (!ic_first_dev) {
260 		if (user_dev_name[0])
261 			printk(KERN_ERR "IP-Config: Device `%s' not found.\n", user_dev_name);
262 		else
263 			printk(KERN_ERR "IP-Config: No network devices available.\n");
264 		return -ENODEV;
265 	}
266 	return 0;
267 }
268 
269 static void __init ic_close_devs(void)
270 {
271 	struct ic_device *d, *next;
272 	struct net_device *dev;
273 
274 	rtnl_lock();
275 	next = ic_first_dev;
276 	while ((d = next)) {
277 		next = d->next;
278 		dev = d->dev;
279 		if (dev != ic_dev) {
280 			DBG(("IP-Config: Downing %s\n", dev->name));
281 			dev_change_flags(dev, d->flags);
282 		}
283 		kfree(d);
284 	}
285 	rtnl_unlock();
286 }
287 
288 /*
289  *	Interface to various network functions.
290  */
291 
292 static inline void
293 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
294 {
295 	sin->sin_family = AF_INET;
296 	sin->sin_addr.s_addr = addr;
297 	sin->sin_port = port;
298 }
299 
300 static int __init ic_devinet_ioctl(unsigned int cmd, struct ifreq *arg)
301 {
302 	int res;
303 
304 	mm_segment_t oldfs = get_fs();
305 	set_fs(get_ds());
306 	res = devinet_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
307 	set_fs(oldfs);
308 	return res;
309 }
310 
311 static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
312 {
313 	int res;
314 
315 	mm_segment_t oldfs = get_fs();
316 	set_fs(get_ds());
317 	res = dev_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
318 	set_fs(oldfs);
319 	return res;
320 }
321 
322 static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg)
323 {
324 	int res;
325 
326 	mm_segment_t oldfs = get_fs();
327 	set_fs(get_ds());
328 	res = ip_rt_ioctl(&init_net, cmd, (void __user *) arg);
329 	set_fs(oldfs);
330 	return res;
331 }
332 
333 /*
334  *	Set up interface addresses and routes.
335  */
336 
337 static int __init ic_setup_if(void)
338 {
339 	struct ifreq ir;
340 	struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
341 	int err;
342 
343 	memset(&ir, 0, sizeof(ir));
344 	strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->name);
345 	set_sockaddr(sin, ic_myaddr, 0);
346 	if ((err = ic_devinet_ioctl(SIOCSIFADDR, &ir)) < 0) {
347 		printk(KERN_ERR "IP-Config: Unable to set interface address (%d).\n", err);
348 		return -1;
349 	}
350 	set_sockaddr(sin, ic_netmask, 0);
351 	if ((err = ic_devinet_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
352 		printk(KERN_ERR "IP-Config: Unable to set interface netmask (%d).\n", err);
353 		return -1;
354 	}
355 	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
356 	if ((err = ic_devinet_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
357 		printk(KERN_ERR "IP-Config: Unable to set interface broadcast address (%d).\n", err);
358 		return -1;
359 	}
360 	/* Handle the case where we need non-standard MTU on the boot link (a network
361 	 * using jumbo frames, for instance).  If we can't set the mtu, don't error
362 	 * out, we'll try to muddle along.
363 	 */
364 	if (ic_dev_mtu != 0) {
365 		strcpy(ir.ifr_name, ic_dev->name);
366 		ir.ifr_mtu = ic_dev_mtu;
367 		if ((err = ic_dev_ioctl(SIOCSIFMTU, &ir)) < 0)
368 			printk(KERN_ERR "IP-Config: Unable to set interface mtu to %d (%d).\n",
369 			                 ic_dev_mtu, err);
370 	}
371 	return 0;
372 }
373 
374 static int __init ic_setup_routes(void)
375 {
376 	/* No need to setup device routes, only the default route... */
377 
378 	if (ic_gateway != NONE) {
379 		struct rtentry rm;
380 		int err;
381 
382 		memset(&rm, 0, sizeof(rm));
383 		if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
384 			printk(KERN_ERR "IP-Config: Gateway not on directly connected network.\n");
385 			return -1;
386 		}
387 		set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
388 		set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
389 		set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
390 		rm.rt_flags = RTF_UP | RTF_GATEWAY;
391 		if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) {
392 			printk(KERN_ERR "IP-Config: Cannot add default route (%d).\n", err);
393 			return -1;
394 		}
395 	}
396 
397 	return 0;
398 }
399 
400 /*
401  *	Fill in default values for all missing parameters.
402  */
403 
404 static int __init ic_defaults(void)
405 {
406 	/*
407 	 *	At this point we have no userspace running so need not
408 	 *	claim locks on system_utsname
409 	 */
410 
411 	if (!ic_host_name_set)
412 		sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
413 
414 	if (root_server_addr == NONE)
415 		root_server_addr = ic_servaddr;
416 
417 	if (ic_netmask == NONE) {
418 		if (IN_CLASSA(ntohl(ic_myaddr)))
419 			ic_netmask = htonl(IN_CLASSA_NET);
420 		else if (IN_CLASSB(ntohl(ic_myaddr)))
421 			ic_netmask = htonl(IN_CLASSB_NET);
422 		else if (IN_CLASSC(ntohl(ic_myaddr)))
423 			ic_netmask = htonl(IN_CLASSC_NET);
424 		else {
425 			printk(KERN_ERR "IP-Config: Unable to guess netmask for address %pI4\n",
426 				&ic_myaddr);
427 			return -1;
428 		}
429 		printk("IP-Config: Guessing netmask %pI4\n", &ic_netmask);
430 	}
431 
432 	return 0;
433 }
434 
435 /*
436  *	RARP support.
437  */
438 
439 #ifdef IPCONFIG_RARP
440 
441 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
442 
443 static struct packet_type rarp_packet_type __initdata = {
444 	.type =	cpu_to_be16(ETH_P_RARP),
445 	.func =	ic_rarp_recv,
446 };
447 
448 static inline void __init ic_rarp_init(void)
449 {
450 	dev_add_pack(&rarp_packet_type);
451 }
452 
453 static inline void __init ic_rarp_cleanup(void)
454 {
455 	dev_remove_pack(&rarp_packet_type);
456 }
457 
458 /*
459  *  Process received RARP packet.
460  */
461 static int __init
462 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
463 {
464 	struct arphdr *rarp;
465 	unsigned char *rarp_ptr;
466 	__be32 sip, tip;
467 	unsigned char *sha, *tha;		/* s for "source", t for "target" */
468 	struct ic_device *d;
469 
470 	if (!net_eq(dev_net(dev), &init_net))
471 		goto drop;
472 
473 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
474 		return NET_RX_DROP;
475 
476 	if (!pskb_may_pull(skb, sizeof(struct arphdr)))
477 		goto drop;
478 
479 	/* Basic sanity checks can be done without the lock.  */
480 	rarp = (struct arphdr *)skb_transport_header(skb);
481 
482 	/* If this test doesn't pass, it's not IP, or we should
483 	 * ignore it anyway.
484 	 */
485 	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
486 		goto drop;
487 
488 	/* If it's not a RARP reply, delete it. */
489 	if (rarp->ar_op != htons(ARPOP_RREPLY))
490 		goto drop;
491 
492 	/* If it's not Ethernet, delete it. */
493 	if (rarp->ar_pro != htons(ETH_P_IP))
494 		goto drop;
495 
496 	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
497 		goto drop;
498 
499 	/* OK, it is all there and looks valid, process... */
500 	rarp = (struct arphdr *)skb_transport_header(skb);
501 	rarp_ptr = (unsigned char *) (rarp + 1);
502 
503 	/* One reply at a time, please. */
504 	spin_lock(&ic_recv_lock);
505 
506 	/* If we already have a reply, just drop the packet */
507 	if (ic_got_reply)
508 		goto drop_unlock;
509 
510 	/* Find the ic_device that the packet arrived on */
511 	d = ic_first_dev;
512 	while (d && d->dev != dev)
513 		d = d->next;
514 	if (!d)
515 		goto drop_unlock;	/* should never happen */
516 
517 	/* Extract variable-width fields */
518 	sha = rarp_ptr;
519 	rarp_ptr += dev->addr_len;
520 	memcpy(&sip, rarp_ptr, 4);
521 	rarp_ptr += 4;
522 	tha = rarp_ptr;
523 	rarp_ptr += dev->addr_len;
524 	memcpy(&tip, rarp_ptr, 4);
525 
526 	/* Discard packets which are not meant for us. */
527 	if (memcmp(tha, dev->dev_addr, dev->addr_len))
528 		goto drop_unlock;
529 
530 	/* Discard packets which are not from specified server. */
531 	if (ic_servaddr != NONE && ic_servaddr != sip)
532 		goto drop_unlock;
533 
534 	/* We have a winner! */
535 	ic_dev = dev;
536 	if (ic_myaddr == NONE)
537 		ic_myaddr = tip;
538 	ic_servaddr = sip;
539 	ic_got_reply = IC_RARP;
540 
541 drop_unlock:
542 	/* Show's over.  Nothing to see here.  */
543 	spin_unlock(&ic_recv_lock);
544 
545 drop:
546 	/* Throw the packet out. */
547 	kfree_skb(skb);
548 	return 0;
549 }
550 
551 
552 /*
553  *  Send RARP request packet over a single interface.
554  */
555 static void __init ic_rarp_send_if(struct ic_device *d)
556 {
557 	struct net_device *dev = d->dev;
558 	arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
559 		 dev->dev_addr, dev->dev_addr);
560 }
561 #endif
562 
563 /*
564  *	DHCP/BOOTP support.
565  */
566 
567 #ifdef IPCONFIG_BOOTP
568 
569 struct bootp_pkt {		/* BOOTP packet format */
570 	struct iphdr iph;	/* IP header */
571 	struct udphdr udph;	/* UDP header */
572 	u8 op;			/* 1=request, 2=reply */
573 	u8 htype;		/* HW address type */
574 	u8 hlen;		/* HW address length */
575 	u8 hops;		/* Used only by gateways */
576 	__be32 xid;		/* Transaction ID */
577 	__be16 secs;		/* Seconds since we started */
578 	__be16 flags;		/* Just what it says */
579 	__be32 client_ip;		/* Client's IP address if known */
580 	__be32 your_ip;		/* Assigned IP address */
581 	__be32 server_ip;		/* (Next, e.g. NFS) Server's IP address */
582 	__be32 relay_ip;		/* IP address of BOOTP relay */
583 	u8 hw_addr[16];		/* Client's HW address */
584 	u8 serv_name[64];	/* Server host name */
585 	u8 boot_file[128];	/* Name of boot file */
586 	u8 exten[312];		/* DHCP options / BOOTP vendor extensions */
587 };
588 
589 /* packet ops */
590 #define BOOTP_REQUEST	1
591 #define BOOTP_REPLY	2
592 
593 /* DHCP message types */
594 #define DHCPDISCOVER	1
595 #define DHCPOFFER	2
596 #define DHCPREQUEST	3
597 #define DHCPDECLINE	4
598 #define DHCPACK		5
599 #define DHCPNAK		6
600 #define DHCPRELEASE	7
601 #define DHCPINFORM	8
602 
603 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
604 
605 static struct packet_type bootp_packet_type __initdata = {
606 	.type =	cpu_to_be16(ETH_P_IP),
607 	.func =	ic_bootp_recv,
608 };
609 
610 
611 /*
612  *  Initialize DHCP/BOOTP extension fields in the request.
613  */
614 
615 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
616 
617 #ifdef IPCONFIG_DHCP
618 
619 static void __init
620 ic_dhcp_init_options(u8 *options)
621 {
622 	u8 mt = ((ic_servaddr == NONE)
623 		 ? DHCPDISCOVER : DHCPREQUEST);
624 	u8 *e = options;
625 	int len;
626 
627 #ifdef IPCONFIG_DEBUG
628 	printk("DHCP: Sending message type %d\n", mt);
629 #endif
630 
631 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
632 	e += 4;
633 
634 	*e++ = 53;		/* DHCP message type */
635 	*e++ = 1;
636 	*e++ = mt;
637 
638 	if (mt == DHCPREQUEST) {
639 		*e++ = 54;	/* Server ID (IP address) */
640 		*e++ = 4;
641 		memcpy(e, &ic_servaddr, 4);
642 		e += 4;
643 
644 		*e++ = 50;	/* Requested IP address */
645 		*e++ = 4;
646 		memcpy(e, &ic_myaddr, 4);
647 		e += 4;
648 	}
649 
650 	/* always? */
651 	{
652 		static const u8 ic_req_params[] = {
653 			1,	/* Subnet mask */
654 			3,	/* Default gateway */
655 			6,	/* DNS server */
656 			12,	/* Host name */
657 			15,	/* Domain name */
658 			17,	/* Boot path */
659 			26,	/* MTU */
660 			40,	/* NIS domain name */
661 		};
662 
663 		*e++ = 55;	/* Parameter request list */
664 		*e++ = sizeof(ic_req_params);
665 		memcpy(e, ic_req_params, sizeof(ic_req_params));
666 		e += sizeof(ic_req_params);
667 
668 		if (*vendor_class_identifier) {
669 			printk(KERN_INFO "DHCP: sending class identifier \"%s\"\n",
670 			       vendor_class_identifier);
671 			*e++ = 60;	/* Class-identifier */
672 			len = strlen(vendor_class_identifier);
673 			*e++ = len;
674 			memcpy(e, vendor_class_identifier, len);
675 			e += len;
676 		}
677 	}
678 
679 	*e++ = 255;	/* End of the list */
680 }
681 
682 #endif /* IPCONFIG_DHCP */
683 
684 static void __init ic_bootp_init_ext(u8 *e)
685 {
686 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
687 	e += 4;
688 	*e++ = 1;		/* Subnet mask request */
689 	*e++ = 4;
690 	e += 4;
691 	*e++ = 3;		/* Default gateway request */
692 	*e++ = 4;
693 	e += 4;
694 	*e++ = 5;		/* Name server request */
695 	*e++ = 8;
696 	e += 8;
697 	*e++ = 12;		/* Host name request */
698 	*e++ = 32;
699 	e += 32;
700 	*e++ = 40;		/* NIS Domain name request */
701 	*e++ = 32;
702 	e += 32;
703 	*e++ = 17;		/* Boot path */
704 	*e++ = 40;
705 	e += 40;
706 
707 	*e++ = 57;		/* set extension buffer size for reply */
708 	*e++ = 2;
709 	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
710 	*e++ = 150;
711 
712 	*e++ = 255;		/* End of the list */
713 }
714 
715 
716 /*
717  *  Initialize the DHCP/BOOTP mechanism.
718  */
719 static inline void __init ic_bootp_init(void)
720 {
721 	int i;
722 
723 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
724 		ic_nameservers[i] = NONE;
725 
726 	dev_add_pack(&bootp_packet_type);
727 }
728 
729 
730 /*
731  *  DHCP/BOOTP cleanup.
732  */
733 static inline void __init ic_bootp_cleanup(void)
734 {
735 	dev_remove_pack(&bootp_packet_type);
736 }
737 
738 
739 /*
740  *  Send DHCP/BOOTP request to single interface.
741  */
742 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
743 {
744 	struct net_device *dev = d->dev;
745 	struct sk_buff *skb;
746 	struct bootp_pkt *b;
747 	struct iphdr *h;
748 
749 	/* Allocate packet */
750 	skb = alloc_skb(sizeof(struct bootp_pkt) + LL_ALLOCATED_SPACE(dev) + 15,
751 			GFP_KERNEL);
752 	if (!skb)
753 		return;
754 	skb_reserve(skb, LL_RESERVED_SPACE(dev));
755 	b = (struct bootp_pkt *) skb_put(skb, sizeof(struct bootp_pkt));
756 	memset(b, 0, sizeof(struct bootp_pkt));
757 
758 	/* Construct IP header */
759 	skb_reset_network_header(skb);
760 	h = ip_hdr(skb);
761 	h->version = 4;
762 	h->ihl = 5;
763 	h->tot_len = htons(sizeof(struct bootp_pkt));
764 	h->frag_off = htons(IP_DF);
765 	h->ttl = 64;
766 	h->protocol = IPPROTO_UDP;
767 	h->daddr = htonl(INADDR_BROADCAST);
768 	h->check = ip_fast_csum((unsigned char *) h, h->ihl);
769 
770 	/* Construct UDP header */
771 	b->udph.source = htons(68);
772 	b->udph.dest = htons(67);
773 	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
774 	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
775 
776 	/* Construct DHCP/BOOTP header */
777 	b->op = BOOTP_REQUEST;
778 	if (dev->type < 256) /* check for false types */
779 		b->htype = dev->type;
780 	else if (dev->type == ARPHRD_IEEE802_TR) /* fix for token ring */
781 		b->htype = ARPHRD_IEEE802;
782 	else if (dev->type == ARPHRD_FDDI)
783 		b->htype = ARPHRD_ETHER;
784 	else {
785 		printk("Unknown ARP type 0x%04x for device %s\n", dev->type, dev->name);
786 		b->htype = dev->type; /* can cause undefined behavior */
787 	}
788 
789 	/* server_ip and your_ip address are both already zero per RFC2131 */
790 	b->hlen = dev->addr_len;
791 	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
792 	b->secs = htons(jiffies_diff / HZ);
793 	b->xid = d->xid;
794 
795 	/* add DHCP options or BOOTP extensions */
796 #ifdef IPCONFIG_DHCP
797 	if (ic_proto_enabled & IC_USE_DHCP)
798 		ic_dhcp_init_options(b->exten);
799 	else
800 #endif
801 		ic_bootp_init_ext(b->exten);
802 
803 	/* Chain packet down the line... */
804 	skb->dev = dev;
805 	skb->protocol = htons(ETH_P_IP);
806 	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
807 			    dev->broadcast, dev->dev_addr, skb->len) < 0 ||
808 	    dev_queue_xmit(skb) < 0)
809 		printk("E");
810 }
811 
812 
813 /*
814  *  Copy BOOTP-supplied string if not already set.
815  */
816 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
817 {
818 	if (!len)
819 		return 0;
820 	if (len > max-1)
821 		len = max-1;
822 	memcpy(dest, src, len);
823 	dest[len] = '\0';
824 	return 1;
825 }
826 
827 
828 /*
829  *  Process BOOTP extensions.
830  */
831 static void __init ic_do_bootp_ext(u8 *ext)
832 {
833        u8 servers;
834        int i;
835 	u16 mtu;
836 
837 #ifdef IPCONFIG_DEBUG
838 	u8 *c;
839 
840 	printk("DHCP/BOOTP: Got extension %d:",*ext);
841 	for (c=ext+2; c<ext+2+ext[1]; c++)
842 		printk(" %02x", *c);
843 	printk("\n");
844 #endif
845 
846 	switch (*ext++) {
847 		case 1:		/* Subnet mask */
848 			if (ic_netmask == NONE)
849 				memcpy(&ic_netmask, ext+1, 4);
850 			break;
851 		case 3:		/* Default gateway */
852 			if (ic_gateway == NONE)
853 				memcpy(&ic_gateway, ext+1, 4);
854 			break;
855 		case 6:		/* DNS server */
856 			servers= *ext/4;
857 			if (servers > CONF_NAMESERVERS_MAX)
858 				servers = CONF_NAMESERVERS_MAX;
859 			for (i = 0; i < servers; i++) {
860 				if (ic_nameservers[i] == NONE)
861 					memcpy(&ic_nameservers[i], ext+1+4*i, 4);
862 			}
863 			break;
864 		case 12:	/* Host name */
865 			ic_bootp_string(utsname()->nodename, ext+1, *ext, __NEW_UTS_LEN);
866 			ic_host_name_set = 1;
867 			break;
868 		case 15:	/* Domain name (DNS) */
869 			ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
870 			break;
871 		case 17:	/* Root path */
872 			if (!root_server_path[0])
873 				ic_bootp_string(root_server_path, ext+1, *ext, sizeof(root_server_path));
874 			break;
875 		case 26:	/* Interface MTU */
876 			memcpy(&mtu, ext+1, sizeof(mtu));
877 			ic_dev_mtu = ntohs(mtu);
878 			break;
879 		case 40:	/* NIS Domain name (_not_ DNS) */
880 			ic_bootp_string(utsname()->domainname, ext+1, *ext, __NEW_UTS_LEN);
881 			break;
882 	}
883 }
884 
885 
886 /*
887  *  Receive BOOTP reply.
888  */
889 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
890 {
891 	struct bootp_pkt *b;
892 	struct iphdr *h;
893 	struct ic_device *d;
894 	int len, ext_len;
895 
896 	if (!net_eq(dev_net(dev), &init_net))
897 		goto drop;
898 
899 	/* Perform verifications before taking the lock.  */
900 	if (skb->pkt_type == PACKET_OTHERHOST)
901 		goto drop;
902 
903 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
904 		return NET_RX_DROP;
905 
906 	if (!pskb_may_pull(skb,
907 			   sizeof(struct iphdr) +
908 			   sizeof(struct udphdr)))
909 		goto drop;
910 
911 	b = (struct bootp_pkt *)skb_network_header(skb);
912 	h = &b->iph;
913 
914 	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
915 		goto drop;
916 
917 	/* Fragments are not supported */
918 	if (h->frag_off & htons(IP_OFFSET | IP_MF)) {
919 		if (net_ratelimit())
920 			printk(KERN_ERR "DHCP/BOOTP: Ignoring fragmented "
921 			       "reply.\n");
922 		goto drop;
923 	}
924 
925 	if (skb->len < ntohs(h->tot_len))
926 		goto drop;
927 
928 	if (ip_fast_csum((char *) h, h->ihl))
929 		goto drop;
930 
931 	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
932 		goto drop;
933 
934 	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
935 		goto drop;
936 
937 	len = ntohs(b->udph.len) - sizeof(struct udphdr);
938 	ext_len = len - (sizeof(*b) -
939 			 sizeof(struct iphdr) -
940 			 sizeof(struct udphdr) -
941 			 sizeof(b->exten));
942 	if (ext_len < 0)
943 		goto drop;
944 
945 	/* Ok the front looks good, make sure we can get at the rest.  */
946 	if (!pskb_may_pull(skb, skb->len))
947 		goto drop;
948 
949 	b = (struct bootp_pkt *)skb_network_header(skb);
950 	h = &b->iph;
951 
952 	/* One reply at a time, please. */
953 	spin_lock(&ic_recv_lock);
954 
955 	/* If we already have a reply, just drop the packet */
956 	if (ic_got_reply)
957 		goto drop_unlock;
958 
959 	/* Find the ic_device that the packet arrived on */
960 	d = ic_first_dev;
961 	while (d && d->dev != dev)
962 		d = d->next;
963 	if (!d)
964 		goto drop_unlock;  /* should never happen */
965 
966 	/* Is it a reply to our BOOTP request? */
967 	if (b->op != BOOTP_REPLY ||
968 	    b->xid != d->xid) {
969 		if (net_ratelimit())
970 			printk(KERN_ERR "DHCP/BOOTP: Reply not for us, "
971 			       "op[%x] xid[%x]\n",
972 			       b->op, b->xid);
973 		goto drop_unlock;
974 	}
975 
976 	/* Is it a reply for the device we are configuring? */
977 	if (b->xid != ic_dev_xid) {
978 		if (net_ratelimit())
979 			printk(KERN_ERR "DHCP/BOOTP: Ignoring delayed packet \n");
980 		goto drop_unlock;
981 	}
982 
983 	/* Parse extensions */
984 	if (ext_len >= 4 &&
985 	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
986 		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
987 		u8 *ext;
988 
989 #ifdef IPCONFIG_DHCP
990 		if (ic_proto_enabled & IC_USE_DHCP) {
991 			__be32 server_id = NONE;
992 			int mt = 0;
993 
994 			ext = &b->exten[4];
995 			while (ext < end && *ext != 0xff) {
996 				u8 *opt = ext++;
997 				if (*opt == 0)	/* Padding */
998 					continue;
999 				ext += *ext + 1;
1000 				if (ext >= end)
1001 					break;
1002 				switch (*opt) {
1003 				case 53:	/* Message type */
1004 					if (opt[1])
1005 						mt = opt[2];
1006 					break;
1007 				case 54:	/* Server ID (IP address) */
1008 					if (opt[1] >= 4)
1009 						memcpy(&server_id, opt + 2, 4);
1010 					break;
1011 				}
1012 			}
1013 
1014 #ifdef IPCONFIG_DEBUG
1015 			printk("DHCP: Got message type %d\n", mt);
1016 #endif
1017 
1018 			switch (mt) {
1019 			case DHCPOFFER:
1020 				/* While in the process of accepting one offer,
1021 				 * ignore all others.
1022 				 */
1023 				if (ic_myaddr != NONE)
1024 					goto drop_unlock;
1025 
1026 				/* Let's accept that offer. */
1027 				ic_myaddr = b->your_ip;
1028 				ic_servaddr = server_id;
1029 #ifdef IPCONFIG_DEBUG
1030 				printk("DHCP: Offered address %pI4 by server %pI4\n",
1031 				       &ic_myaddr, &ic_servaddr);
1032 #endif
1033 				/* The DHCP indicated server address takes
1034 				 * precedence over the bootp header one if
1035 				 * they are different.
1036 				 */
1037 				if ((server_id != NONE) &&
1038 				    (b->server_ip != server_id))
1039 					b->server_ip = ic_servaddr;
1040 				break;
1041 
1042 			case DHCPACK:
1043 				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1044 					goto drop_unlock;
1045 
1046 				/* Yeah! */
1047 				break;
1048 
1049 			default:
1050 				/* Urque.  Forget it*/
1051 				ic_myaddr = NONE;
1052 				ic_servaddr = NONE;
1053 				goto drop_unlock;
1054 			}
1055 
1056 			ic_dhcp_msgtype = mt;
1057 
1058 		}
1059 #endif /* IPCONFIG_DHCP */
1060 
1061 		ext = &b->exten[4];
1062 		while (ext < end && *ext != 0xff) {
1063 			u8 *opt = ext++;
1064 			if (*opt == 0)	/* Padding */
1065 				continue;
1066 			ext += *ext + 1;
1067 			if (ext < end)
1068 				ic_do_bootp_ext(opt);
1069 		}
1070 	}
1071 
1072 	/* We have a winner! */
1073 	ic_dev = dev;
1074 	ic_myaddr = b->your_ip;
1075 	ic_servaddr = b->server_ip;
1076 	if (ic_gateway == NONE && b->relay_ip)
1077 		ic_gateway = b->relay_ip;
1078 	if (ic_nameservers[0] == NONE)
1079 		ic_nameservers[0] = ic_servaddr;
1080 	ic_got_reply = IC_BOOTP;
1081 
1082 drop_unlock:
1083 	/* Show's over.  Nothing to see here.  */
1084 	spin_unlock(&ic_recv_lock);
1085 
1086 drop:
1087 	/* Throw the packet out. */
1088 	kfree_skb(skb);
1089 
1090 	return 0;
1091 }
1092 
1093 
1094 #endif
1095 
1096 
1097 /*
1098  *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
1099  */
1100 
1101 #ifdef IPCONFIG_DYNAMIC
1102 
1103 static int __init ic_dynamic(void)
1104 {
1105 	int retries;
1106 	struct ic_device *d;
1107 	unsigned long start_jiffies, timeout, jiff;
1108 	int do_bootp = ic_proto_have_if & IC_BOOTP;
1109 	int do_rarp = ic_proto_have_if & IC_RARP;
1110 
1111 	/*
1112 	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1113 	 * This routine gets only called when some pieces of information
1114 	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1115 	 */
1116 	if (!ic_proto_enabled) {
1117 		printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
1118 		return -1;
1119 	}
1120 
1121 #ifdef IPCONFIG_BOOTP
1122 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1123 		printk(KERN_ERR "DHCP/BOOTP: No suitable device found.\n");
1124 #endif
1125 #ifdef IPCONFIG_RARP
1126 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1127 		printk(KERN_ERR "RARP: No suitable device found.\n");
1128 #endif
1129 
1130 	if (!ic_proto_have_if)
1131 		/* Error message already printed */
1132 		return -1;
1133 
1134 	/*
1135 	 * Setup protocols
1136 	 */
1137 #ifdef IPCONFIG_BOOTP
1138 	if (do_bootp)
1139 		ic_bootp_init();
1140 #endif
1141 #ifdef IPCONFIG_RARP
1142 	if (do_rarp)
1143 		ic_rarp_init();
1144 #endif
1145 
1146 	/*
1147 	 * Send requests and wait, until we get an answer. This loop
1148 	 * seems to be a terrible waste of CPU time, but actually there is
1149 	 * only one process running at all, so we don't need to use any
1150 	 * scheduler functions.
1151 	 * [Actually we could now, but the nothing else running note still
1152 	 *  applies.. - AC]
1153 	 */
1154 	printk(KERN_NOTICE "Sending %s%s%s requests .",
1155 	       do_bootp
1156 		? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1157 	       (do_bootp && do_rarp) ? " and " : "",
1158 	       do_rarp ? "RARP" : "");
1159 
1160 	start_jiffies = jiffies;
1161 	d = ic_first_dev;
1162 	retries = CONF_SEND_RETRIES;
1163 	get_random_bytes(&timeout, sizeof(timeout));
1164 	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned) CONF_TIMEOUT_RANDOM);
1165 	for (;;) {
1166 		/* Track the device we are configuring */
1167 		ic_dev_xid = d->xid;
1168 
1169 #ifdef IPCONFIG_BOOTP
1170 		if (do_bootp && (d->able & IC_BOOTP))
1171 			ic_bootp_send_if(d, jiffies - start_jiffies);
1172 #endif
1173 #ifdef IPCONFIG_RARP
1174 		if (do_rarp && (d->able & IC_RARP))
1175 			ic_rarp_send_if(d);
1176 #endif
1177 
1178 		jiff = jiffies + (d->next ? CONF_INTER_TIMEOUT : timeout);
1179 		while (time_before(jiffies, jiff) && !ic_got_reply)
1180 			schedule_timeout_uninterruptible(1);
1181 #ifdef IPCONFIG_DHCP
1182 		/* DHCP isn't done until we get a DHCPACK. */
1183 		if ((ic_got_reply & IC_BOOTP) &&
1184 		    (ic_proto_enabled & IC_USE_DHCP) &&
1185 		    ic_dhcp_msgtype != DHCPACK) {
1186 			ic_got_reply = 0;
1187 			printk(",");
1188 			continue;
1189 		}
1190 #endif /* IPCONFIG_DHCP */
1191 
1192 		if (ic_got_reply) {
1193 			printk(" OK\n");
1194 			break;
1195 		}
1196 
1197 		if ((d = d->next))
1198 			continue;
1199 
1200 		if (! --retries) {
1201 			printk(" timed out!\n");
1202 			break;
1203 		}
1204 
1205 		d = ic_first_dev;
1206 
1207 		timeout = timeout CONF_TIMEOUT_MULT;
1208 		if (timeout > CONF_TIMEOUT_MAX)
1209 			timeout = CONF_TIMEOUT_MAX;
1210 
1211 		printk(".");
1212 	}
1213 
1214 #ifdef IPCONFIG_BOOTP
1215 	if (do_bootp)
1216 		ic_bootp_cleanup();
1217 #endif
1218 #ifdef IPCONFIG_RARP
1219 	if (do_rarp)
1220 		ic_rarp_cleanup();
1221 #endif
1222 
1223 	if (!ic_got_reply) {
1224 		ic_myaddr = NONE;
1225 		return -1;
1226 	}
1227 
1228 	printk("IP-Config: Got %s answer from %pI4, ",
1229 		((ic_got_reply & IC_RARP) ? "RARP"
1230 		 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1231 		&ic_servaddr);
1232 	printk("my address is %pI4\n", &ic_myaddr);
1233 
1234 	return 0;
1235 }
1236 
1237 #endif /* IPCONFIG_DYNAMIC */
1238 
1239 #ifdef CONFIG_PROC_FS
1240 
1241 static int pnp_seq_show(struct seq_file *seq, void *v)
1242 {
1243 	int i;
1244 
1245 	if (ic_proto_used & IC_PROTO)
1246 		seq_printf(seq, "#PROTO: %s\n",
1247 			   (ic_proto_used & IC_RARP) ? "RARP"
1248 			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1249 	else
1250 		seq_puts(seq, "#MANUAL\n");
1251 
1252 	if (ic_domain[0])
1253 		seq_printf(seq,
1254 			   "domain %s\n", ic_domain);
1255 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1256 		if (ic_nameservers[i] != NONE)
1257 			seq_printf(seq, "nameserver %pI4\n",
1258 				   &ic_nameservers[i]);
1259 	}
1260 	if (ic_servaddr != NONE)
1261 		seq_printf(seq, "bootserver %pI4\n",
1262 			   &ic_servaddr);
1263 	return 0;
1264 }
1265 
1266 static int pnp_seq_open(struct inode *indoe, struct file *file)
1267 {
1268 	return single_open(file, pnp_seq_show, NULL);
1269 }
1270 
1271 static const struct file_operations pnp_seq_fops = {
1272 	.owner		= THIS_MODULE,
1273 	.open		= pnp_seq_open,
1274 	.read		= seq_read,
1275 	.llseek		= seq_lseek,
1276 	.release	= single_release,
1277 };
1278 #endif /* CONFIG_PROC_FS */
1279 
1280 /*
1281  *  Extract IP address from the parameter string if needed. Note that we
1282  *  need to have root_server_addr set _before_ IPConfig gets called as it
1283  *  can override it.
1284  */
1285 __be32 __init root_nfs_parse_addr(char *name)
1286 {
1287 	__be32 addr;
1288 	int octets = 0;
1289 	char *cp, *cq;
1290 
1291 	cp = cq = name;
1292 	while (octets < 4) {
1293 		while (*cp >= '0' && *cp <= '9')
1294 			cp++;
1295 		if (cp == cq || cp - cq > 3)
1296 			break;
1297 		if (*cp == '.' || octets == 3)
1298 			octets++;
1299 		if (octets < 4)
1300 			cp++;
1301 		cq = cp;
1302 	}
1303 	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1304 		if (*cp == ':')
1305 			*cp++ = '\0';
1306 		addr = in_aton(name);
1307 		memmove(name, cp, strlen(cp) + 1);
1308 	} else
1309 		addr = NONE;
1310 
1311 	return addr;
1312 }
1313 
1314 #define DEVICE_WAIT_MAX		12 /* 12 seconds */
1315 
1316 static int __init wait_for_devices(void)
1317 {
1318 	int i;
1319 
1320 	msleep(CONF_PRE_OPEN);
1321 	for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1322 		struct net_device *dev;
1323 		int found = 0;
1324 
1325 		rtnl_lock();
1326 		for_each_netdev(&init_net, dev) {
1327 			if (ic_device_match(dev)) {
1328 				found = 1;
1329 				break;
1330 			}
1331 		}
1332 		rtnl_unlock();
1333 		if (found)
1334 			return 0;
1335 		ssleep(1);
1336 	}
1337 	return -ENODEV;
1338 }
1339 
1340 /*
1341  *	IP Autoconfig dispatcher.
1342  */
1343 
1344 static int __init ip_auto_config(void)
1345 {
1346 	__be32 addr;
1347 #ifdef IPCONFIG_DYNAMIC
1348 	int retries = CONF_OPEN_RETRIES;
1349 #endif
1350 	int err;
1351 
1352 #ifdef CONFIG_PROC_FS
1353 	proc_net_fops_create(&init_net, "pnp", S_IRUGO, &pnp_seq_fops);
1354 #endif /* CONFIG_PROC_FS */
1355 
1356 	if (!ic_enable)
1357 		return 0;
1358 
1359 	DBG(("IP-Config: Entered.\n"));
1360 #ifdef IPCONFIG_DYNAMIC
1361  try_try_again:
1362 #endif
1363 	/* Wait for devices to appear */
1364 	err = wait_for_devices();
1365 	if (err)
1366 		return err;
1367 
1368 	/* Setup all network devices */
1369 	err = ic_open_devs();
1370 	if (err)
1371 		return err;
1372 
1373 	/* Give drivers a chance to settle */
1374 	ssleep(CONF_POST_OPEN);
1375 
1376 	/*
1377 	 * If the config information is insufficient (e.g., our IP address or
1378 	 * IP address of the boot server is missing or we have multiple network
1379 	 * interfaces and no default was set), use BOOTP or RARP to get the
1380 	 * missing values.
1381 	 */
1382 	if (ic_myaddr == NONE ||
1383 #ifdef CONFIG_ROOT_NFS
1384 	    (root_server_addr == NONE &&
1385 	     ic_servaddr == NONE &&
1386 	     ROOT_DEV == Root_NFS) ||
1387 #endif
1388 	    ic_first_dev->next) {
1389 #ifdef IPCONFIG_DYNAMIC
1390 		if (ic_dynamic() < 0) {
1391 			ic_close_devs();
1392 
1393 			/*
1394 			 * I don't know why, but sometimes the
1395 			 * eepro100 driver (at least) gets upset and
1396 			 * doesn't work the first time it's opened.
1397 			 * But then if you close it and reopen it, it
1398 			 * works just fine.  So we need to try that at
1399 			 * least once before giving up.
1400 			 *
1401 			 * Also, if the root will be NFS-mounted, we
1402 			 * have nowhere to go if DHCP fails.  So we
1403 			 * just have to keep trying forever.
1404 			 *
1405 			 * 				-- Chip
1406 			 */
1407 #ifdef CONFIG_ROOT_NFS
1408 			if (ROOT_DEV ==  Root_NFS) {
1409 				printk(KERN_ERR
1410 					"IP-Config: Retrying forever (NFS root)...\n");
1411 				goto try_try_again;
1412 			}
1413 #endif
1414 
1415 			if (--retries) {
1416 				printk(KERN_ERR
1417 				       "IP-Config: Reopening network devices...\n");
1418 				goto try_try_again;
1419 			}
1420 
1421 			/* Oh, well.  At least we tried. */
1422 			printk(KERN_ERR "IP-Config: Auto-configuration of network failed.\n");
1423 			return -1;
1424 		}
1425 #else /* !DYNAMIC */
1426 		printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
1427 		ic_close_devs();
1428 		return -1;
1429 #endif /* IPCONFIG_DYNAMIC */
1430 	} else {
1431 		/* Device selected manually or only one device -> use it */
1432 		ic_dev = ic_first_dev->dev;
1433 	}
1434 
1435 	addr = root_nfs_parse_addr(root_server_path);
1436 	if (root_server_addr == NONE)
1437 		root_server_addr = addr;
1438 
1439 	/*
1440 	 * Use defaults whereever applicable.
1441 	 */
1442 	if (ic_defaults() < 0)
1443 		return -1;
1444 
1445 	/*
1446 	 * Close all network devices except the device we've
1447 	 * autoconfigured and set up routes.
1448 	 */
1449 	ic_close_devs();
1450 	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1451 		return -1;
1452 
1453 	/*
1454 	 * Record which protocol was actually used.
1455 	 */
1456 #ifdef IPCONFIG_DYNAMIC
1457 	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1458 #endif
1459 
1460 #ifndef IPCONFIG_SILENT
1461 	/*
1462 	 * Clue in the operator.
1463 	 */
1464 	printk("IP-Config: Complete:");
1465 	printk("\n     device=%s", ic_dev->name);
1466 	printk(", addr=%pI4", &ic_myaddr);
1467 	printk(", mask=%pI4", &ic_netmask);
1468 	printk(", gw=%pI4", &ic_gateway);
1469 	printk(",\n     host=%s, domain=%s, nis-domain=%s",
1470 	       utsname()->nodename, ic_domain, utsname()->domainname);
1471 	printk(",\n     bootserver=%pI4", &ic_servaddr);
1472 	printk(", rootserver=%pI4", &root_server_addr);
1473 	printk(", rootpath=%s", root_server_path);
1474 	if (ic_dev_mtu)
1475 		printk(", mtu=%d", ic_dev_mtu);
1476 	printk("\n");
1477 #endif /* !SILENT */
1478 
1479 	return 0;
1480 }
1481 
1482 late_initcall(ip_auto_config);
1483 
1484 
1485 /*
1486  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1487  *  command line parameter.  See Documentation/filesystems/nfs/nfsroot.txt.
1488  */
1489 static int __init ic_proto_name(char *name)
1490 {
1491 	if (!strcmp(name, "on") || !strcmp(name, "any")) {
1492 		return 1;
1493 	}
1494 	if (!strcmp(name, "off") || !strcmp(name, "none")) {
1495 		return 0;
1496 	}
1497 #ifdef CONFIG_IP_PNP_DHCP
1498 	else if (!strcmp(name, "dhcp")) {
1499 		ic_proto_enabled &= ~IC_RARP;
1500 		return 1;
1501 	}
1502 #endif
1503 #ifdef CONFIG_IP_PNP_BOOTP
1504 	else if (!strcmp(name, "bootp")) {
1505 		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1506 		return 1;
1507 	}
1508 #endif
1509 #ifdef CONFIG_IP_PNP_RARP
1510 	else if (!strcmp(name, "rarp")) {
1511 		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1512 		return 1;
1513 	}
1514 #endif
1515 #ifdef IPCONFIG_DYNAMIC
1516 	else if (!strcmp(name, "both")) {
1517 		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1518 		return 1;
1519 	}
1520 #endif
1521 	return 0;
1522 }
1523 
1524 static int __init ip_auto_config_setup(char *addrs)
1525 {
1526 	char *cp, *ip, *dp;
1527 	int num = 0;
1528 
1529 	ic_set_manually = 1;
1530 	ic_enable = 1;
1531 
1532 	/*
1533 	 * If any dhcp, bootp etc options are set, leave autoconfig on
1534 	 * and skip the below static IP processing.
1535 	 */
1536 	if (ic_proto_name(addrs))
1537 		return 1;
1538 
1539 	/* If no static IP is given, turn off autoconfig and bail.  */
1540 	if (*addrs == 0 ||
1541 	    strcmp(addrs, "off") == 0 ||
1542 	    strcmp(addrs, "none") == 0) {
1543 		ic_enable = 0;
1544 		return 1;
1545 	}
1546 
1547 	/* Parse string for static IP assignment.  */
1548 	ip = addrs;
1549 	while (ip && *ip) {
1550 		if ((cp = strchr(ip, ':')))
1551 			*cp++ = '\0';
1552 		if (strlen(ip) > 0) {
1553 			DBG(("IP-Config: Parameter #%d: `%s'\n", num, ip));
1554 			switch (num) {
1555 			case 0:
1556 				if ((ic_myaddr = in_aton(ip)) == ANY)
1557 					ic_myaddr = NONE;
1558 				break;
1559 			case 1:
1560 				if ((ic_servaddr = in_aton(ip)) == ANY)
1561 					ic_servaddr = NONE;
1562 				break;
1563 			case 2:
1564 				if ((ic_gateway = in_aton(ip)) == ANY)
1565 					ic_gateway = NONE;
1566 				break;
1567 			case 3:
1568 				if ((ic_netmask = in_aton(ip)) == ANY)
1569 					ic_netmask = NONE;
1570 				break;
1571 			case 4:
1572 				if ((dp = strchr(ip, '.'))) {
1573 					*dp++ = '\0';
1574 					strlcpy(utsname()->domainname, dp,
1575 						sizeof(utsname()->domainname));
1576 				}
1577 				strlcpy(utsname()->nodename, ip,
1578 					sizeof(utsname()->nodename));
1579 				ic_host_name_set = 1;
1580 				break;
1581 			case 5:
1582 				strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1583 				break;
1584 			case 6:
1585 				if (ic_proto_name(ip) == 0 &&
1586 				    ic_myaddr == NONE) {
1587 					ic_enable = 0;
1588 				}
1589 				break;
1590 			}
1591 		}
1592 		ip = cp;
1593 		num++;
1594 	}
1595 
1596 	return 1;
1597 }
1598 
1599 static int __init nfsaddrs_config_setup(char *addrs)
1600 {
1601 	return ip_auto_config_setup(addrs);
1602 }
1603 
1604 static int __init vendor_class_identifier_setup(char *addrs)
1605 {
1606 	if (strlcpy(vendor_class_identifier, addrs,
1607 		    sizeof(vendor_class_identifier))
1608 	    >= sizeof(vendor_class_identifier))
1609 		printk(KERN_WARNING "DHCP: vendorclass too long, truncated to \"%s\"",
1610 		       vendor_class_identifier);
1611 	return 1;
1612 }
1613 
1614 __setup("ip=", ip_auto_config_setup);
1615 __setup("nfsaddrs=", nfsaddrs_config_setup);
1616 __setup("dhcpclass=", vendor_class_identifier_setup);
1617