xref: /openbmc/linux/net/ipv4/ipconfig.c (revision c819e2cf)
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 <linux/export.h>
58 #include <net/net_namespace.h>
59 #include <net/arp.h>
60 #include <net/ip.h>
61 #include <net/ipconfig.h>
62 #include <net/route.h>
63 
64 #include <asm/uaccess.h>
65 #include <net/checksum.h>
66 #include <asm/processor.h>
67 
68 /* Define this to allow debugging output */
69 #undef IPCONFIG_DEBUG
70 
71 #ifdef IPCONFIG_DEBUG
72 #define DBG(x) printk x
73 #else
74 #define DBG(x) do { } while(0)
75 #endif
76 
77 #if defined(CONFIG_IP_PNP_DHCP)
78 #define IPCONFIG_DHCP
79 #endif
80 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
81 #define IPCONFIG_BOOTP
82 #endif
83 #if defined(CONFIG_IP_PNP_RARP)
84 #define IPCONFIG_RARP
85 #endif
86 #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
87 #define IPCONFIG_DYNAMIC
88 #endif
89 
90 /* Define the friendly delay before and after opening net devices */
91 #define CONF_POST_OPEN		10	/* After opening: 10 msecs */
92 #define CONF_CARRIER_TIMEOUT	120000	/* Wait for carrier timeout */
93 
94 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
95 #define CONF_OPEN_RETRIES 	2	/* (Re)open devices twice */
96 #define CONF_SEND_RETRIES 	6	/* Send six requests per open */
97 #define CONF_INTER_TIMEOUT	(HZ/2)	/* Inter-device timeout: 1/2 second */
98 #define CONF_BASE_TIMEOUT	(HZ*2)	/* Initial timeout: 2 seconds */
99 #define CONF_TIMEOUT_RANDOM	(HZ)	/* Maximum amount of randomization */
100 #define CONF_TIMEOUT_MULT	*7/4	/* Rate of timeout growth */
101 #define CONF_TIMEOUT_MAX	(HZ*30)	/* Maximum allowed timeout */
102 #define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
103 					   - '3' from resolv.h */
104 
105 #define NONE cpu_to_be32(INADDR_NONE)
106 #define ANY cpu_to_be32(INADDR_ANY)
107 
108 /*
109  * Public IP configuration
110  */
111 
112 /* This is used by platforms which might be able to set the ipconfig
113  * variables using firmware environment vars.  If this is set, it will
114  * ignore such firmware variables.
115  */
116 int ic_set_manually __initdata = 0;		/* IPconfig parameters set manually */
117 
118 static int ic_enable __initdata;		/* IP config enabled? */
119 
120 /* Protocol choice */
121 int ic_proto_enabled __initdata = 0
122 #ifdef IPCONFIG_BOOTP
123 			| IC_BOOTP
124 #endif
125 #ifdef CONFIG_IP_PNP_DHCP
126 			| IC_USE_DHCP
127 #endif
128 #ifdef IPCONFIG_RARP
129 			| IC_RARP
130 #endif
131 			;
132 
133 static int ic_host_name_set __initdata;	/* Host name set by us? */
134 
135 __be32 ic_myaddr = NONE;		/* My IP address */
136 static __be32 ic_netmask = NONE;	/* Netmask for local subnet */
137 __be32 ic_gateway = NONE;	/* Gateway IP address */
138 
139 __be32 ic_addrservaddr = NONE;	/* IP Address of the IP addresses'server */
140 
141 __be32 ic_servaddr = NONE;	/* Boot server IP address */
142 
143 __be32 root_server_addr = NONE;	/* Address of NFS server */
144 u8 root_server_path[256] = { 0, };	/* Path to mount as root */
145 
146 /* vendor class identifier */
147 static char vendor_class_identifier[253] __initdata;
148 
149 /* Persistent data: */
150 
151 static int ic_proto_used;			/* Protocol used, if any */
152 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
153 static u8 ic_domain[64];		/* DNS (not NIS) domain name */
154 
155 /*
156  * Private state.
157  */
158 
159 /* Name of user-selected boot device */
160 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
161 
162 /* Protocols supported by available interfaces */
163 static int ic_proto_have_if __initdata;
164 
165 /* MTU for boot device */
166 static int ic_dev_mtu __initdata;
167 
168 #ifdef IPCONFIG_DYNAMIC
169 static DEFINE_SPINLOCK(ic_recv_lock);
170 static volatile int ic_got_reply __initdata;    /* Proto(s) that replied */
171 #endif
172 #ifdef IPCONFIG_DHCP
173 static int ic_dhcp_msgtype __initdata;	/* DHCP msg type received */
174 #endif
175 
176 
177 /*
178  *	Network devices
179  */
180 
181 struct ic_device {
182 	struct ic_device *next;
183 	struct net_device *dev;
184 	unsigned short flags;
185 	short able;
186 	__be32 xid;
187 };
188 
189 static struct ic_device *ic_first_dev __initdata;	/* List of open device */
190 static struct net_device *ic_dev __initdata;		/* Selected device */
191 
192 static bool __init ic_is_init_dev(struct net_device *dev)
193 {
194 	if (dev->flags & IFF_LOOPBACK)
195 		return false;
196 	return user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
197 	    (!(dev->flags & IFF_LOOPBACK) &&
198 	     (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
199 	     strncmp(dev->name, "dummy", 5));
200 }
201 
202 static int __init ic_open_devs(void)
203 {
204 	struct ic_device *d, **last;
205 	struct net_device *dev;
206 	unsigned short oflags;
207 	unsigned long start, next_msg;
208 
209 	last = &ic_first_dev;
210 	rtnl_lock();
211 
212 	/* bring loopback device up first */
213 	for_each_netdev(&init_net, dev) {
214 		if (!(dev->flags & IFF_LOOPBACK))
215 			continue;
216 		if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
217 			pr_err("IP-Config: Failed to open %s\n", dev->name);
218 	}
219 
220 	for_each_netdev(&init_net, dev) {
221 		if (ic_is_init_dev(dev)) {
222 			int able = 0;
223 			if (dev->mtu >= 364)
224 				able |= IC_BOOTP;
225 			else
226 				pr_warn("DHCP/BOOTP: Ignoring device %s, MTU %d too small",
227 					dev->name, dev->mtu);
228 			if (!(dev->flags & IFF_NOARP))
229 				able |= IC_RARP;
230 			able &= ic_proto_enabled;
231 			if (ic_proto_enabled && !able)
232 				continue;
233 			oflags = dev->flags;
234 			if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
235 				pr_err("IP-Config: Failed to open %s\n",
236 				       dev->name);
237 				continue;
238 			}
239 			if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
240 				rtnl_unlock();
241 				return -ENOMEM;
242 			}
243 			d->dev = dev;
244 			*last = d;
245 			last = &d->next;
246 			d->flags = oflags;
247 			d->able = able;
248 			if (able & IC_BOOTP)
249 				get_random_bytes(&d->xid, sizeof(__be32));
250 			else
251 				d->xid = 0;
252 			ic_proto_have_if |= able;
253 			DBG(("IP-Config: %s UP (able=%d, xid=%08x)\n",
254 				dev->name, able, d->xid));
255 		}
256 	}
257 
258 	/* no point in waiting if we could not bring up at least one device */
259 	if (!ic_first_dev)
260 		goto have_carrier;
261 
262 	/* wait for a carrier on at least one device */
263 	start = jiffies;
264 	next_msg = start + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
265 	while (time_before(jiffies, start +
266 			   msecs_to_jiffies(CONF_CARRIER_TIMEOUT))) {
267 		int wait, elapsed;
268 
269 		for_each_netdev(&init_net, dev)
270 			if (ic_is_init_dev(dev) && netif_carrier_ok(dev))
271 				goto have_carrier;
272 
273 		msleep(1);
274 
275 		if (time_before(jiffies, next_msg))
276 			continue;
277 
278 		elapsed = jiffies_to_msecs(jiffies - start);
279 		wait = (CONF_CARRIER_TIMEOUT - elapsed + 500)/1000;
280 		pr_info("Waiting up to %d more seconds for network.\n", wait);
281 		next_msg = jiffies + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
282 	}
283 have_carrier:
284 	rtnl_unlock();
285 
286 	*last = NULL;
287 
288 	if (!ic_first_dev) {
289 		if (user_dev_name[0])
290 			pr_err("IP-Config: Device `%s' not found\n",
291 			       user_dev_name);
292 		else
293 			pr_err("IP-Config: No network devices available\n");
294 		return -ENODEV;
295 	}
296 	return 0;
297 }
298 
299 static void __init ic_close_devs(void)
300 {
301 	struct ic_device *d, *next;
302 	struct net_device *dev;
303 
304 	rtnl_lock();
305 	next = ic_first_dev;
306 	while ((d = next)) {
307 		next = d->next;
308 		dev = d->dev;
309 		if (dev != ic_dev) {
310 			DBG(("IP-Config: Downing %s\n", dev->name));
311 			dev_change_flags(dev, d->flags);
312 		}
313 		kfree(d);
314 	}
315 	rtnl_unlock();
316 }
317 
318 /*
319  *	Interface to various network functions.
320  */
321 
322 static inline void
323 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
324 {
325 	sin->sin_family = AF_INET;
326 	sin->sin_addr.s_addr = addr;
327 	sin->sin_port = port;
328 }
329 
330 static int __init ic_devinet_ioctl(unsigned int cmd, struct ifreq *arg)
331 {
332 	int res;
333 
334 	mm_segment_t oldfs = get_fs();
335 	set_fs(get_ds());
336 	res = devinet_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
337 	set_fs(oldfs);
338 	return res;
339 }
340 
341 static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
342 {
343 	int res;
344 
345 	mm_segment_t oldfs = get_fs();
346 	set_fs(get_ds());
347 	res = dev_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
348 	set_fs(oldfs);
349 	return res;
350 }
351 
352 static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg)
353 {
354 	int res;
355 
356 	mm_segment_t oldfs = get_fs();
357 	set_fs(get_ds());
358 	res = ip_rt_ioctl(&init_net, cmd, (void __user *) arg);
359 	set_fs(oldfs);
360 	return res;
361 }
362 
363 /*
364  *	Set up interface addresses and routes.
365  */
366 
367 static int __init ic_setup_if(void)
368 {
369 	struct ifreq ir;
370 	struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
371 	int err;
372 
373 	memset(&ir, 0, sizeof(ir));
374 	strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->name);
375 	set_sockaddr(sin, ic_myaddr, 0);
376 	if ((err = ic_devinet_ioctl(SIOCSIFADDR, &ir)) < 0) {
377 		pr_err("IP-Config: Unable to set interface address (%d)\n",
378 		       err);
379 		return -1;
380 	}
381 	set_sockaddr(sin, ic_netmask, 0);
382 	if ((err = ic_devinet_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
383 		pr_err("IP-Config: Unable to set interface netmask (%d)\n",
384 		       err);
385 		return -1;
386 	}
387 	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
388 	if ((err = ic_devinet_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
389 		pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
390 		       err);
391 		return -1;
392 	}
393 	/* Handle the case where we need non-standard MTU on the boot link (a network
394 	 * using jumbo frames, for instance).  If we can't set the mtu, don't error
395 	 * out, we'll try to muddle along.
396 	 */
397 	if (ic_dev_mtu != 0) {
398 		strcpy(ir.ifr_name, ic_dev->name);
399 		ir.ifr_mtu = ic_dev_mtu;
400 		if ((err = ic_dev_ioctl(SIOCSIFMTU, &ir)) < 0)
401 			pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
402 			       ic_dev_mtu, err);
403 	}
404 	return 0;
405 }
406 
407 static int __init ic_setup_routes(void)
408 {
409 	/* No need to setup device routes, only the default route... */
410 
411 	if (ic_gateway != NONE) {
412 		struct rtentry rm;
413 		int err;
414 
415 		memset(&rm, 0, sizeof(rm));
416 		if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
417 			pr_err("IP-Config: Gateway not on directly connected network\n");
418 			return -1;
419 		}
420 		set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
421 		set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
422 		set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
423 		rm.rt_flags = RTF_UP | RTF_GATEWAY;
424 		if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) {
425 			pr_err("IP-Config: Cannot add default route (%d)\n",
426 			       err);
427 			return -1;
428 		}
429 	}
430 
431 	return 0;
432 }
433 
434 /*
435  *	Fill in default values for all missing parameters.
436  */
437 
438 static int __init ic_defaults(void)
439 {
440 	/*
441 	 *	At this point we have no userspace running so need not
442 	 *	claim locks on system_utsname
443 	 */
444 
445 	if (!ic_host_name_set)
446 		sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
447 
448 	if (root_server_addr == NONE)
449 		root_server_addr = ic_servaddr;
450 
451 	if (ic_netmask == NONE) {
452 		if (IN_CLASSA(ntohl(ic_myaddr)))
453 			ic_netmask = htonl(IN_CLASSA_NET);
454 		else if (IN_CLASSB(ntohl(ic_myaddr)))
455 			ic_netmask = htonl(IN_CLASSB_NET);
456 		else if (IN_CLASSC(ntohl(ic_myaddr)))
457 			ic_netmask = htonl(IN_CLASSC_NET);
458 		else {
459 			pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
460 			       &ic_myaddr);
461 			return -1;
462 		}
463 		printk("IP-Config: Guessing netmask %pI4\n", &ic_netmask);
464 	}
465 
466 	return 0;
467 }
468 
469 /*
470  *	RARP support.
471  */
472 
473 #ifdef IPCONFIG_RARP
474 
475 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
476 
477 static struct packet_type rarp_packet_type __initdata = {
478 	.type =	cpu_to_be16(ETH_P_RARP),
479 	.func =	ic_rarp_recv,
480 };
481 
482 static inline void __init ic_rarp_init(void)
483 {
484 	dev_add_pack(&rarp_packet_type);
485 }
486 
487 static inline void __init ic_rarp_cleanup(void)
488 {
489 	dev_remove_pack(&rarp_packet_type);
490 }
491 
492 /*
493  *  Process received RARP packet.
494  */
495 static int __init
496 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
497 {
498 	struct arphdr *rarp;
499 	unsigned char *rarp_ptr;
500 	__be32 sip, tip;
501 	unsigned char *tha;		/* t for "target" */
502 	struct ic_device *d;
503 
504 	if (!net_eq(dev_net(dev), &init_net))
505 		goto drop;
506 
507 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
508 		return NET_RX_DROP;
509 
510 	if (!pskb_may_pull(skb, sizeof(struct arphdr)))
511 		goto drop;
512 
513 	/* Basic sanity checks can be done without the lock.  */
514 	rarp = (struct arphdr *)skb_transport_header(skb);
515 
516 	/* If this test doesn't pass, it's not IP, or we should
517 	 * ignore it anyway.
518 	 */
519 	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
520 		goto drop;
521 
522 	/* If it's not a RARP reply, delete it. */
523 	if (rarp->ar_op != htons(ARPOP_RREPLY))
524 		goto drop;
525 
526 	/* If it's not Ethernet, delete it. */
527 	if (rarp->ar_pro != htons(ETH_P_IP))
528 		goto drop;
529 
530 	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
531 		goto drop;
532 
533 	/* OK, it is all there and looks valid, process... */
534 	rarp = (struct arphdr *)skb_transport_header(skb);
535 	rarp_ptr = (unsigned char *) (rarp + 1);
536 
537 	/* One reply at a time, please. */
538 	spin_lock(&ic_recv_lock);
539 
540 	/* If we already have a reply, just drop the packet */
541 	if (ic_got_reply)
542 		goto drop_unlock;
543 
544 	/* Find the ic_device that the packet arrived on */
545 	d = ic_first_dev;
546 	while (d && d->dev != dev)
547 		d = d->next;
548 	if (!d)
549 		goto drop_unlock;	/* should never happen */
550 
551 	/* Extract variable-width fields */
552 	rarp_ptr += dev->addr_len;
553 	memcpy(&sip, rarp_ptr, 4);
554 	rarp_ptr += 4;
555 	tha = rarp_ptr;
556 	rarp_ptr += dev->addr_len;
557 	memcpy(&tip, rarp_ptr, 4);
558 
559 	/* Discard packets which are not meant for us. */
560 	if (memcmp(tha, dev->dev_addr, dev->addr_len))
561 		goto drop_unlock;
562 
563 	/* Discard packets which are not from specified server. */
564 	if (ic_servaddr != NONE && ic_servaddr != sip)
565 		goto drop_unlock;
566 
567 	/* We have a winner! */
568 	ic_dev = dev;
569 	if (ic_myaddr == NONE)
570 		ic_myaddr = tip;
571 	ic_servaddr = sip;
572 	ic_addrservaddr = sip;
573 	ic_got_reply = IC_RARP;
574 
575 drop_unlock:
576 	/* Show's over.  Nothing to see here.  */
577 	spin_unlock(&ic_recv_lock);
578 
579 drop:
580 	/* Throw the packet out. */
581 	kfree_skb(skb);
582 	return 0;
583 }
584 
585 
586 /*
587  *  Send RARP request packet over a single interface.
588  */
589 static void __init ic_rarp_send_if(struct ic_device *d)
590 {
591 	struct net_device *dev = d->dev;
592 	arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
593 		 dev->dev_addr, dev->dev_addr);
594 }
595 #endif
596 
597 /*
598  *  Predefine Nameservers
599  */
600 static inline void __init ic_nameservers_predef(void)
601 {
602 	int i;
603 
604 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
605 		ic_nameservers[i] = NONE;
606 }
607 
608 /*
609  *	DHCP/BOOTP support.
610  */
611 
612 #ifdef IPCONFIG_BOOTP
613 
614 struct bootp_pkt {		/* BOOTP packet format */
615 	struct iphdr iph;	/* IP header */
616 	struct udphdr udph;	/* UDP header */
617 	u8 op;			/* 1=request, 2=reply */
618 	u8 htype;		/* HW address type */
619 	u8 hlen;		/* HW address length */
620 	u8 hops;		/* Used only by gateways */
621 	__be32 xid;		/* Transaction ID */
622 	__be16 secs;		/* Seconds since we started */
623 	__be16 flags;		/* Just what it says */
624 	__be32 client_ip;		/* Client's IP address if known */
625 	__be32 your_ip;		/* Assigned IP address */
626 	__be32 server_ip;		/* (Next, e.g. NFS) Server's IP address */
627 	__be32 relay_ip;		/* IP address of BOOTP relay */
628 	u8 hw_addr[16];		/* Client's HW address */
629 	u8 serv_name[64];	/* Server host name */
630 	u8 boot_file[128];	/* Name of boot file */
631 	u8 exten[312];		/* DHCP options / BOOTP vendor extensions */
632 };
633 
634 /* packet ops */
635 #define BOOTP_REQUEST	1
636 #define BOOTP_REPLY	2
637 
638 /* DHCP message types */
639 #define DHCPDISCOVER	1
640 #define DHCPOFFER	2
641 #define DHCPREQUEST	3
642 #define DHCPDECLINE	4
643 #define DHCPACK		5
644 #define DHCPNAK		6
645 #define DHCPRELEASE	7
646 #define DHCPINFORM	8
647 
648 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
649 
650 static struct packet_type bootp_packet_type __initdata = {
651 	.type =	cpu_to_be16(ETH_P_IP),
652 	.func =	ic_bootp_recv,
653 };
654 
655 static __be32 ic_dev_xid;		/* Device under configuration */
656 
657 /*
658  *  Initialize DHCP/BOOTP extension fields in the request.
659  */
660 
661 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
662 
663 #ifdef IPCONFIG_DHCP
664 
665 static void __init
666 ic_dhcp_init_options(u8 *options)
667 {
668 	u8 mt = ((ic_servaddr == NONE)
669 		 ? DHCPDISCOVER : DHCPREQUEST);
670 	u8 *e = options;
671 	int len;
672 
673 #ifdef IPCONFIG_DEBUG
674 	printk("DHCP: Sending message type %d\n", mt);
675 #endif
676 
677 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
678 	e += 4;
679 
680 	*e++ = 53;		/* DHCP message type */
681 	*e++ = 1;
682 	*e++ = mt;
683 
684 	if (mt == DHCPREQUEST) {
685 		*e++ = 54;	/* Server ID (IP address) */
686 		*e++ = 4;
687 		memcpy(e, &ic_servaddr, 4);
688 		e += 4;
689 
690 		*e++ = 50;	/* Requested IP address */
691 		*e++ = 4;
692 		memcpy(e, &ic_myaddr, 4);
693 		e += 4;
694 	}
695 
696 	/* always? */
697 	{
698 		static const u8 ic_req_params[] = {
699 			1,	/* Subnet mask */
700 			3,	/* Default gateway */
701 			6,	/* DNS server */
702 			12,	/* Host name */
703 			15,	/* Domain name */
704 			17,	/* Boot path */
705 			26,	/* MTU */
706 			40,	/* NIS domain name */
707 		};
708 
709 		*e++ = 55;	/* Parameter request list */
710 		*e++ = sizeof(ic_req_params);
711 		memcpy(e, ic_req_params, sizeof(ic_req_params));
712 		e += sizeof(ic_req_params);
713 
714 		if (ic_host_name_set) {
715 			*e++ = 12;	/* host-name */
716 			len = strlen(utsname()->nodename);
717 			*e++ = len;
718 			memcpy(e, utsname()->nodename, len);
719 			e += len;
720 		}
721 		if (*vendor_class_identifier) {
722 			pr_info("DHCP: sending class identifier \"%s\"\n",
723 				vendor_class_identifier);
724 			*e++ = 60;	/* Class-identifier */
725 			len = strlen(vendor_class_identifier);
726 			*e++ = len;
727 			memcpy(e, vendor_class_identifier, len);
728 			e += len;
729 		}
730 	}
731 
732 	*e++ = 255;	/* End of the list */
733 }
734 
735 #endif /* IPCONFIG_DHCP */
736 
737 static void __init ic_bootp_init_ext(u8 *e)
738 {
739 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
740 	e += 4;
741 	*e++ = 1;		/* Subnet mask request */
742 	*e++ = 4;
743 	e += 4;
744 	*e++ = 3;		/* Default gateway request */
745 	*e++ = 4;
746 	e += 4;
747 	*e++ = 5;		/* Name server request */
748 	*e++ = 8;
749 	e += 8;
750 	*e++ = 12;		/* Host name request */
751 	*e++ = 32;
752 	e += 32;
753 	*e++ = 40;		/* NIS Domain name request */
754 	*e++ = 32;
755 	e += 32;
756 	*e++ = 17;		/* Boot path */
757 	*e++ = 40;
758 	e += 40;
759 
760 	*e++ = 57;		/* set extension buffer size for reply */
761 	*e++ = 2;
762 	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
763 	*e++ = 150;
764 
765 	*e++ = 255;		/* End of the list */
766 }
767 
768 
769 /*
770  *  Initialize the DHCP/BOOTP mechanism.
771  */
772 static inline void __init ic_bootp_init(void)
773 {
774 	ic_nameservers_predef();
775 
776 	dev_add_pack(&bootp_packet_type);
777 }
778 
779 
780 /*
781  *  DHCP/BOOTP cleanup.
782  */
783 static inline void __init ic_bootp_cleanup(void)
784 {
785 	dev_remove_pack(&bootp_packet_type);
786 }
787 
788 
789 /*
790  *  Send DHCP/BOOTP request to single interface.
791  */
792 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
793 {
794 	struct net_device *dev = d->dev;
795 	struct sk_buff *skb;
796 	struct bootp_pkt *b;
797 	struct iphdr *h;
798 	int hlen = LL_RESERVED_SPACE(dev);
799 	int tlen = dev->needed_tailroom;
800 
801 	/* Allocate packet */
802 	skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
803 			GFP_KERNEL);
804 	if (!skb)
805 		return;
806 	skb_reserve(skb, hlen);
807 	b = (struct bootp_pkt *) skb_put(skb, sizeof(struct bootp_pkt));
808 	memset(b, 0, sizeof(struct bootp_pkt));
809 
810 	/* Construct IP header */
811 	skb_reset_network_header(skb);
812 	h = ip_hdr(skb);
813 	h->version = 4;
814 	h->ihl = 5;
815 	h->tot_len = htons(sizeof(struct bootp_pkt));
816 	h->frag_off = htons(IP_DF);
817 	h->ttl = 64;
818 	h->protocol = IPPROTO_UDP;
819 	h->daddr = htonl(INADDR_BROADCAST);
820 	h->check = ip_fast_csum((unsigned char *) h, h->ihl);
821 
822 	/* Construct UDP header */
823 	b->udph.source = htons(68);
824 	b->udph.dest = htons(67);
825 	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
826 	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
827 
828 	/* Construct DHCP/BOOTP header */
829 	b->op = BOOTP_REQUEST;
830 	if (dev->type < 256) /* check for false types */
831 		b->htype = dev->type;
832 	else if (dev->type == ARPHRD_FDDI)
833 		b->htype = ARPHRD_ETHER;
834 	else {
835 		printk("Unknown ARP type 0x%04x for device %s\n", dev->type, dev->name);
836 		b->htype = dev->type; /* can cause undefined behavior */
837 	}
838 
839 	/* server_ip and your_ip address are both already zero per RFC2131 */
840 	b->hlen = dev->addr_len;
841 	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
842 	b->secs = htons(jiffies_diff / HZ);
843 	b->xid = d->xid;
844 
845 	/* add DHCP options or BOOTP extensions */
846 #ifdef IPCONFIG_DHCP
847 	if (ic_proto_enabled & IC_USE_DHCP)
848 		ic_dhcp_init_options(b->exten);
849 	else
850 #endif
851 		ic_bootp_init_ext(b->exten);
852 
853 	/* Chain packet down the line... */
854 	skb->dev = dev;
855 	skb->protocol = htons(ETH_P_IP);
856 	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
857 			    dev->broadcast, dev->dev_addr, skb->len) < 0) {
858 		kfree_skb(skb);
859 		printk("E");
860 		return;
861 	}
862 
863 	if (dev_queue_xmit(skb) < 0)
864 		printk("E");
865 }
866 
867 
868 /*
869  *  Copy BOOTP-supplied string if not already set.
870  */
871 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
872 {
873 	if (!len)
874 		return 0;
875 	if (len > max-1)
876 		len = max-1;
877 	memcpy(dest, src, len);
878 	dest[len] = '\0';
879 	return 1;
880 }
881 
882 
883 /*
884  *  Process BOOTP extensions.
885  */
886 static void __init ic_do_bootp_ext(u8 *ext)
887 {
888 	u8 servers;
889 	int i;
890 	__be16 mtu;
891 
892 #ifdef IPCONFIG_DEBUG
893 	u8 *c;
894 
895 	printk("DHCP/BOOTP: Got extension %d:",*ext);
896 	for (c=ext+2; c<ext+2+ext[1]; c++)
897 		printk(" %02x", *c);
898 	printk("\n");
899 #endif
900 
901 	switch (*ext++) {
902 	case 1:		/* Subnet mask */
903 		if (ic_netmask == NONE)
904 			memcpy(&ic_netmask, ext+1, 4);
905 		break;
906 	case 3:		/* Default gateway */
907 		if (ic_gateway == NONE)
908 			memcpy(&ic_gateway, ext+1, 4);
909 		break;
910 	case 6:		/* DNS server */
911 		servers= *ext/4;
912 		if (servers > CONF_NAMESERVERS_MAX)
913 			servers = CONF_NAMESERVERS_MAX;
914 		for (i = 0; i < servers; i++) {
915 			if (ic_nameservers[i] == NONE)
916 				memcpy(&ic_nameservers[i], ext+1+4*i, 4);
917 		}
918 		break;
919 	case 12:	/* Host name */
920 		ic_bootp_string(utsname()->nodename, ext+1, *ext,
921 				__NEW_UTS_LEN);
922 		ic_host_name_set = 1;
923 		break;
924 	case 15:	/* Domain name (DNS) */
925 		ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
926 		break;
927 	case 17:	/* Root path */
928 		if (!root_server_path[0])
929 			ic_bootp_string(root_server_path, ext+1, *ext,
930 					sizeof(root_server_path));
931 		break;
932 	case 26:	/* Interface MTU */
933 		memcpy(&mtu, ext+1, sizeof(mtu));
934 		ic_dev_mtu = ntohs(mtu);
935 		break;
936 	case 40:	/* NIS Domain name (_not_ DNS) */
937 		ic_bootp_string(utsname()->domainname, ext+1, *ext,
938 				__NEW_UTS_LEN);
939 		break;
940 	}
941 }
942 
943 
944 /*
945  *  Receive BOOTP reply.
946  */
947 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
948 {
949 	struct bootp_pkt *b;
950 	struct iphdr *h;
951 	struct ic_device *d;
952 	int len, ext_len;
953 
954 	if (!net_eq(dev_net(dev), &init_net))
955 		goto drop;
956 
957 	/* Perform verifications before taking the lock.  */
958 	if (skb->pkt_type == PACKET_OTHERHOST)
959 		goto drop;
960 
961 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
962 		return NET_RX_DROP;
963 
964 	if (!pskb_may_pull(skb,
965 			   sizeof(struct iphdr) +
966 			   sizeof(struct udphdr)))
967 		goto drop;
968 
969 	b = (struct bootp_pkt *)skb_network_header(skb);
970 	h = &b->iph;
971 
972 	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
973 		goto drop;
974 
975 	/* Fragments are not supported */
976 	if (ip_is_fragment(h)) {
977 		net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
978 		goto drop;
979 	}
980 
981 	if (skb->len < ntohs(h->tot_len))
982 		goto drop;
983 
984 	if (ip_fast_csum((char *) h, h->ihl))
985 		goto drop;
986 
987 	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
988 		goto drop;
989 
990 	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
991 		goto drop;
992 
993 	len = ntohs(b->udph.len) - sizeof(struct udphdr);
994 	ext_len = len - (sizeof(*b) -
995 			 sizeof(struct iphdr) -
996 			 sizeof(struct udphdr) -
997 			 sizeof(b->exten));
998 	if (ext_len < 0)
999 		goto drop;
1000 
1001 	/* Ok the front looks good, make sure we can get at the rest.  */
1002 	if (!pskb_may_pull(skb, skb->len))
1003 		goto drop;
1004 
1005 	b = (struct bootp_pkt *)skb_network_header(skb);
1006 	h = &b->iph;
1007 
1008 	/* One reply at a time, please. */
1009 	spin_lock(&ic_recv_lock);
1010 
1011 	/* If we already have a reply, just drop the packet */
1012 	if (ic_got_reply)
1013 		goto drop_unlock;
1014 
1015 	/* Find the ic_device that the packet arrived on */
1016 	d = ic_first_dev;
1017 	while (d && d->dev != dev)
1018 		d = d->next;
1019 	if (!d)
1020 		goto drop_unlock;  /* should never happen */
1021 
1022 	/* Is it a reply to our BOOTP request? */
1023 	if (b->op != BOOTP_REPLY ||
1024 	    b->xid != d->xid) {
1025 		net_err_ratelimited("DHCP/BOOTP: Reply not for us, op[%x] xid[%x]\n",
1026 				    b->op, b->xid);
1027 		goto drop_unlock;
1028 	}
1029 
1030 	/* Is it a reply for the device we are configuring? */
1031 	if (b->xid != ic_dev_xid) {
1032 		net_err_ratelimited("DHCP/BOOTP: Ignoring delayed packet\n");
1033 		goto drop_unlock;
1034 	}
1035 
1036 	/* Parse extensions */
1037 	if (ext_len >= 4 &&
1038 	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1039 		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1040 		u8 *ext;
1041 
1042 #ifdef IPCONFIG_DHCP
1043 		if (ic_proto_enabled & IC_USE_DHCP) {
1044 			__be32 server_id = NONE;
1045 			int mt = 0;
1046 
1047 			ext = &b->exten[4];
1048 			while (ext < end && *ext != 0xff) {
1049 				u8 *opt = ext++;
1050 				if (*opt == 0)	/* Padding */
1051 					continue;
1052 				ext += *ext + 1;
1053 				if (ext >= end)
1054 					break;
1055 				switch (*opt) {
1056 				case 53:	/* Message type */
1057 					if (opt[1])
1058 						mt = opt[2];
1059 					break;
1060 				case 54:	/* Server ID (IP address) */
1061 					if (opt[1] >= 4)
1062 						memcpy(&server_id, opt + 2, 4);
1063 					break;
1064 				}
1065 			}
1066 
1067 #ifdef IPCONFIG_DEBUG
1068 			printk("DHCP: Got message type %d\n", mt);
1069 #endif
1070 
1071 			switch (mt) {
1072 			case DHCPOFFER:
1073 				/* While in the process of accepting one offer,
1074 				 * ignore all others.
1075 				 */
1076 				if (ic_myaddr != NONE)
1077 					goto drop_unlock;
1078 
1079 				/* Let's accept that offer. */
1080 				ic_myaddr = b->your_ip;
1081 				ic_servaddr = server_id;
1082 #ifdef IPCONFIG_DEBUG
1083 				printk("DHCP: Offered address %pI4 by server %pI4\n",
1084 				       &ic_myaddr, &b->iph.saddr);
1085 #endif
1086 				/* The DHCP indicated server address takes
1087 				 * precedence over the bootp header one if
1088 				 * they are different.
1089 				 */
1090 				if ((server_id != NONE) &&
1091 				    (b->server_ip != server_id))
1092 					b->server_ip = ic_servaddr;
1093 				break;
1094 
1095 			case DHCPACK:
1096 				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1097 					goto drop_unlock;
1098 
1099 				/* Yeah! */
1100 				break;
1101 
1102 			default:
1103 				/* Urque.  Forget it*/
1104 				ic_myaddr = NONE;
1105 				ic_servaddr = NONE;
1106 				goto drop_unlock;
1107 			}
1108 
1109 			ic_dhcp_msgtype = mt;
1110 
1111 		}
1112 #endif /* IPCONFIG_DHCP */
1113 
1114 		ext = &b->exten[4];
1115 		while (ext < end && *ext != 0xff) {
1116 			u8 *opt = ext++;
1117 			if (*opt == 0)	/* Padding */
1118 				continue;
1119 			ext += *ext + 1;
1120 			if (ext < end)
1121 				ic_do_bootp_ext(opt);
1122 		}
1123 	}
1124 
1125 	/* We have a winner! */
1126 	ic_dev = dev;
1127 	ic_myaddr = b->your_ip;
1128 	ic_servaddr = b->server_ip;
1129 	ic_addrservaddr = b->iph.saddr;
1130 	if (ic_gateway == NONE && b->relay_ip)
1131 		ic_gateway = b->relay_ip;
1132 	if (ic_nameservers[0] == NONE)
1133 		ic_nameservers[0] = ic_servaddr;
1134 	ic_got_reply = IC_BOOTP;
1135 
1136 drop_unlock:
1137 	/* Show's over.  Nothing to see here.  */
1138 	spin_unlock(&ic_recv_lock);
1139 
1140 drop:
1141 	/* Throw the packet out. */
1142 	kfree_skb(skb);
1143 
1144 	return 0;
1145 }
1146 
1147 
1148 #endif
1149 
1150 
1151 /*
1152  *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
1153  */
1154 
1155 #ifdef IPCONFIG_DYNAMIC
1156 
1157 static int __init ic_dynamic(void)
1158 {
1159 	int retries;
1160 	struct ic_device *d;
1161 	unsigned long start_jiffies, timeout, jiff;
1162 	int do_bootp = ic_proto_have_if & IC_BOOTP;
1163 	int do_rarp = ic_proto_have_if & IC_RARP;
1164 
1165 	/*
1166 	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1167 	 * This routine gets only called when some pieces of information
1168 	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1169 	 */
1170 	if (!ic_proto_enabled) {
1171 		pr_err("IP-Config: Incomplete network configuration information\n");
1172 		return -1;
1173 	}
1174 
1175 #ifdef IPCONFIG_BOOTP
1176 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1177 		pr_err("DHCP/BOOTP: No suitable device found\n");
1178 #endif
1179 #ifdef IPCONFIG_RARP
1180 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1181 		pr_err("RARP: No suitable device found\n");
1182 #endif
1183 
1184 	if (!ic_proto_have_if)
1185 		/* Error message already printed */
1186 		return -1;
1187 
1188 	/*
1189 	 * Setup protocols
1190 	 */
1191 #ifdef IPCONFIG_BOOTP
1192 	if (do_bootp)
1193 		ic_bootp_init();
1194 #endif
1195 #ifdef IPCONFIG_RARP
1196 	if (do_rarp)
1197 		ic_rarp_init();
1198 #endif
1199 
1200 	/*
1201 	 * Send requests and wait, until we get an answer. This loop
1202 	 * seems to be a terrible waste of CPU time, but actually there is
1203 	 * only one process running at all, so we don't need to use any
1204 	 * scheduler functions.
1205 	 * [Actually we could now, but the nothing else running note still
1206 	 *  applies.. - AC]
1207 	 */
1208 	pr_notice("Sending %s%s%s requests .",
1209 		  do_bootp
1210 		  ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1211 		  (do_bootp && do_rarp) ? " and " : "",
1212 		  do_rarp ? "RARP" : "");
1213 
1214 	start_jiffies = jiffies;
1215 	d = ic_first_dev;
1216 	retries = CONF_SEND_RETRIES;
1217 	get_random_bytes(&timeout, sizeof(timeout));
1218 	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1219 	for (;;) {
1220 #ifdef IPCONFIG_BOOTP
1221 		/* Track the device we are configuring */
1222 		ic_dev_xid = d->xid;
1223 
1224 		if (do_bootp && (d->able & IC_BOOTP))
1225 			ic_bootp_send_if(d, jiffies - start_jiffies);
1226 #endif
1227 #ifdef IPCONFIG_RARP
1228 		if (do_rarp && (d->able & IC_RARP))
1229 			ic_rarp_send_if(d);
1230 #endif
1231 
1232 		jiff = jiffies + (d->next ? CONF_INTER_TIMEOUT : timeout);
1233 		while (time_before(jiffies, jiff) && !ic_got_reply)
1234 			schedule_timeout_uninterruptible(1);
1235 #ifdef IPCONFIG_DHCP
1236 		/* DHCP isn't done until we get a DHCPACK. */
1237 		if ((ic_got_reply & IC_BOOTP) &&
1238 		    (ic_proto_enabled & IC_USE_DHCP) &&
1239 		    ic_dhcp_msgtype != DHCPACK) {
1240 			ic_got_reply = 0;
1241 			pr_cont(",");
1242 			continue;
1243 		}
1244 #endif /* IPCONFIG_DHCP */
1245 
1246 		if (ic_got_reply) {
1247 			pr_cont(" OK\n");
1248 			break;
1249 		}
1250 
1251 		if ((d = d->next))
1252 			continue;
1253 
1254 		if (! --retries) {
1255 			pr_cont(" timed out!\n");
1256 			break;
1257 		}
1258 
1259 		d = ic_first_dev;
1260 
1261 		timeout = timeout CONF_TIMEOUT_MULT;
1262 		if (timeout > CONF_TIMEOUT_MAX)
1263 			timeout = CONF_TIMEOUT_MAX;
1264 
1265 		pr_cont(".");
1266 	}
1267 
1268 #ifdef IPCONFIG_BOOTP
1269 	if (do_bootp)
1270 		ic_bootp_cleanup();
1271 #endif
1272 #ifdef IPCONFIG_RARP
1273 	if (do_rarp)
1274 		ic_rarp_cleanup();
1275 #endif
1276 
1277 	if (!ic_got_reply) {
1278 		ic_myaddr = NONE;
1279 		return -1;
1280 	}
1281 
1282 	printk("IP-Config: Got %s answer from %pI4, ",
1283 		((ic_got_reply & IC_RARP) ? "RARP"
1284 		 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1285 	       &ic_addrservaddr);
1286 	pr_cont("my address is %pI4\n", &ic_myaddr);
1287 
1288 	return 0;
1289 }
1290 
1291 #endif /* IPCONFIG_DYNAMIC */
1292 
1293 #ifdef CONFIG_PROC_FS
1294 
1295 static int pnp_seq_show(struct seq_file *seq, void *v)
1296 {
1297 	int i;
1298 
1299 	if (ic_proto_used & IC_PROTO)
1300 		seq_printf(seq, "#PROTO: %s\n",
1301 			   (ic_proto_used & IC_RARP) ? "RARP"
1302 			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1303 	else
1304 		seq_puts(seq, "#MANUAL\n");
1305 
1306 	if (ic_domain[0])
1307 		seq_printf(seq,
1308 			   "domain %s\n", ic_domain);
1309 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1310 		if (ic_nameservers[i] != NONE)
1311 			seq_printf(seq, "nameserver %pI4\n",
1312 				   &ic_nameservers[i]);
1313 	}
1314 	if (ic_servaddr != NONE)
1315 		seq_printf(seq, "bootserver %pI4\n",
1316 			   &ic_servaddr);
1317 	return 0;
1318 }
1319 
1320 static int pnp_seq_open(struct inode *indoe, struct file *file)
1321 {
1322 	return single_open(file, pnp_seq_show, NULL);
1323 }
1324 
1325 static const struct file_operations pnp_seq_fops = {
1326 	.owner		= THIS_MODULE,
1327 	.open		= pnp_seq_open,
1328 	.read		= seq_read,
1329 	.llseek		= seq_lseek,
1330 	.release	= single_release,
1331 };
1332 #endif /* CONFIG_PROC_FS */
1333 
1334 /*
1335  *  Extract IP address from the parameter string if needed. Note that we
1336  *  need to have root_server_addr set _before_ IPConfig gets called as it
1337  *  can override it.
1338  */
1339 __be32 __init root_nfs_parse_addr(char *name)
1340 {
1341 	__be32 addr;
1342 	int octets = 0;
1343 	char *cp, *cq;
1344 
1345 	cp = cq = name;
1346 	while (octets < 4) {
1347 		while (*cp >= '0' && *cp <= '9')
1348 			cp++;
1349 		if (cp == cq || cp - cq > 3)
1350 			break;
1351 		if (*cp == '.' || octets == 3)
1352 			octets++;
1353 		if (octets < 4)
1354 			cp++;
1355 		cq = cp;
1356 	}
1357 	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1358 		if (*cp == ':')
1359 			*cp++ = '\0';
1360 		addr = in_aton(name);
1361 		memmove(name, cp, strlen(cp) + 1);
1362 	} else
1363 		addr = NONE;
1364 
1365 	return addr;
1366 }
1367 
1368 #define DEVICE_WAIT_MAX		12 /* 12 seconds */
1369 
1370 static int __init wait_for_devices(void)
1371 {
1372 	int i;
1373 
1374 	for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1375 		struct net_device *dev;
1376 		int found = 0;
1377 
1378 		rtnl_lock();
1379 		for_each_netdev(&init_net, dev) {
1380 			if (ic_is_init_dev(dev)) {
1381 				found = 1;
1382 				break;
1383 			}
1384 		}
1385 		rtnl_unlock();
1386 		if (found)
1387 			return 0;
1388 		ssleep(1);
1389 	}
1390 	return -ENODEV;
1391 }
1392 
1393 /*
1394  *	IP Autoconfig dispatcher.
1395  */
1396 
1397 static int __init ip_auto_config(void)
1398 {
1399 	__be32 addr;
1400 #ifdef IPCONFIG_DYNAMIC
1401 	int retries = CONF_OPEN_RETRIES;
1402 #endif
1403 	int err;
1404 	unsigned int i;
1405 
1406 #ifdef CONFIG_PROC_FS
1407 	proc_create("pnp", S_IRUGO, init_net.proc_net, &pnp_seq_fops);
1408 #endif /* CONFIG_PROC_FS */
1409 
1410 	if (!ic_enable)
1411 		return 0;
1412 
1413 	DBG(("IP-Config: Entered.\n"));
1414 #ifdef IPCONFIG_DYNAMIC
1415  try_try_again:
1416 #endif
1417 	/* Wait for devices to appear */
1418 	err = wait_for_devices();
1419 	if (err)
1420 		return err;
1421 
1422 	/* Setup all network devices */
1423 	err = ic_open_devs();
1424 	if (err)
1425 		return err;
1426 
1427 	/* Give drivers a chance to settle */
1428 	msleep(CONF_POST_OPEN);
1429 
1430 	/*
1431 	 * If the config information is insufficient (e.g., our IP address or
1432 	 * IP address of the boot server is missing or we have multiple network
1433 	 * interfaces and no default was set), use BOOTP or RARP to get the
1434 	 * missing values.
1435 	 */
1436 	if (ic_myaddr == NONE ||
1437 #ifdef CONFIG_ROOT_NFS
1438 	    (root_server_addr == NONE &&
1439 	     ic_servaddr == NONE &&
1440 	     ROOT_DEV == Root_NFS) ||
1441 #endif
1442 	    ic_first_dev->next) {
1443 #ifdef IPCONFIG_DYNAMIC
1444 		if (ic_dynamic() < 0) {
1445 			ic_close_devs();
1446 
1447 			/*
1448 			 * I don't know why, but sometimes the
1449 			 * eepro100 driver (at least) gets upset and
1450 			 * doesn't work the first time it's opened.
1451 			 * But then if you close it and reopen it, it
1452 			 * works just fine.  So we need to try that at
1453 			 * least once before giving up.
1454 			 *
1455 			 * Also, if the root will be NFS-mounted, we
1456 			 * have nowhere to go if DHCP fails.  So we
1457 			 * just have to keep trying forever.
1458 			 *
1459 			 * 				-- Chip
1460 			 */
1461 #ifdef CONFIG_ROOT_NFS
1462 			if (ROOT_DEV ==  Root_NFS) {
1463 				pr_err("IP-Config: Retrying forever (NFS root)...\n");
1464 				goto try_try_again;
1465 			}
1466 #endif
1467 
1468 			if (--retries) {
1469 				pr_err("IP-Config: Reopening network devices...\n");
1470 				goto try_try_again;
1471 			}
1472 
1473 			/* Oh, well.  At least we tried. */
1474 			pr_err("IP-Config: Auto-configuration of network failed\n");
1475 			return -1;
1476 		}
1477 #else /* !DYNAMIC */
1478 		pr_err("IP-Config: Incomplete network configuration information\n");
1479 		ic_close_devs();
1480 		return -1;
1481 #endif /* IPCONFIG_DYNAMIC */
1482 	} else {
1483 		/* Device selected manually or only one device -> use it */
1484 		ic_dev = ic_first_dev->dev;
1485 	}
1486 
1487 	addr = root_nfs_parse_addr(root_server_path);
1488 	if (root_server_addr == NONE)
1489 		root_server_addr = addr;
1490 
1491 	/*
1492 	 * Use defaults wherever applicable.
1493 	 */
1494 	if (ic_defaults() < 0)
1495 		return -1;
1496 
1497 	/*
1498 	 * Close all network devices except the device we've
1499 	 * autoconfigured and set up routes.
1500 	 */
1501 	ic_close_devs();
1502 	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1503 		return -1;
1504 
1505 	/*
1506 	 * Record which protocol was actually used.
1507 	 */
1508 #ifdef IPCONFIG_DYNAMIC
1509 	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1510 #endif
1511 
1512 #ifndef IPCONFIG_SILENT
1513 	/*
1514 	 * Clue in the operator.
1515 	 */
1516 	pr_info("IP-Config: Complete:\n");
1517 
1518 	pr_info("     device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1519 		ic_dev->name, ic_dev->addr_len, ic_dev->dev_addr,
1520 		&ic_myaddr, &ic_netmask, &ic_gateway);
1521 	pr_info("     host=%s, domain=%s, nis-domain=%s\n",
1522 		utsname()->nodename, ic_domain, utsname()->domainname);
1523 	pr_info("     bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1524 		&ic_servaddr, &root_server_addr, root_server_path);
1525 	if (ic_dev_mtu)
1526 		pr_cont(", mtu=%d", ic_dev_mtu);
1527 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
1528 		if (ic_nameservers[i] != NONE) {
1529 			pr_info("     nameserver%u=%pI4",
1530 				i, &ic_nameservers[i]);
1531 			break;
1532 		}
1533 	for (i++; i < CONF_NAMESERVERS_MAX; i++)
1534 		if (ic_nameservers[i] != NONE)
1535 			pr_cont(", nameserver%u=%pI4", i, &ic_nameservers[i]);
1536 	pr_cont("\n");
1537 #endif /* !SILENT */
1538 
1539 	return 0;
1540 }
1541 
1542 late_initcall(ip_auto_config);
1543 
1544 
1545 /*
1546  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1547  *  command line parameter.  See Documentation/filesystems/nfs/nfsroot.txt.
1548  */
1549 static int __init ic_proto_name(char *name)
1550 {
1551 	if (!strcmp(name, "on") || !strcmp(name, "any")) {
1552 		return 1;
1553 	}
1554 	if (!strcmp(name, "off") || !strcmp(name, "none")) {
1555 		return 0;
1556 	}
1557 #ifdef CONFIG_IP_PNP_DHCP
1558 	else if (!strcmp(name, "dhcp")) {
1559 		ic_proto_enabled &= ~IC_RARP;
1560 		return 1;
1561 	}
1562 #endif
1563 #ifdef CONFIG_IP_PNP_BOOTP
1564 	else if (!strcmp(name, "bootp")) {
1565 		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1566 		return 1;
1567 	}
1568 #endif
1569 #ifdef CONFIG_IP_PNP_RARP
1570 	else if (!strcmp(name, "rarp")) {
1571 		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1572 		return 1;
1573 	}
1574 #endif
1575 #ifdef IPCONFIG_DYNAMIC
1576 	else if (!strcmp(name, "both")) {
1577 		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1578 		return 1;
1579 	}
1580 #endif
1581 	return 0;
1582 }
1583 
1584 static int __init ip_auto_config_setup(char *addrs)
1585 {
1586 	char *cp, *ip, *dp;
1587 	int num = 0;
1588 
1589 	ic_set_manually = 1;
1590 	ic_enable = 1;
1591 
1592 	/*
1593 	 * If any dhcp, bootp etc options are set, leave autoconfig on
1594 	 * and skip the below static IP processing.
1595 	 */
1596 	if (ic_proto_name(addrs))
1597 		return 1;
1598 
1599 	/* If no static IP is given, turn off autoconfig and bail.  */
1600 	if (*addrs == 0 ||
1601 	    strcmp(addrs, "off") == 0 ||
1602 	    strcmp(addrs, "none") == 0) {
1603 		ic_enable = 0;
1604 		return 1;
1605 	}
1606 
1607 	ic_nameservers_predef();
1608 
1609 	/* Parse string for static IP assignment.  */
1610 	ip = addrs;
1611 	while (ip && *ip) {
1612 		if ((cp = strchr(ip, ':')))
1613 			*cp++ = '\0';
1614 		if (strlen(ip) > 0) {
1615 			DBG(("IP-Config: Parameter #%d: `%s'\n", num, ip));
1616 			switch (num) {
1617 			case 0:
1618 				if ((ic_myaddr = in_aton(ip)) == ANY)
1619 					ic_myaddr = NONE;
1620 				break;
1621 			case 1:
1622 				if ((ic_servaddr = in_aton(ip)) == ANY)
1623 					ic_servaddr = NONE;
1624 				break;
1625 			case 2:
1626 				if ((ic_gateway = in_aton(ip)) == ANY)
1627 					ic_gateway = NONE;
1628 				break;
1629 			case 3:
1630 				if ((ic_netmask = in_aton(ip)) == ANY)
1631 					ic_netmask = NONE;
1632 				break;
1633 			case 4:
1634 				if ((dp = strchr(ip, '.'))) {
1635 					*dp++ = '\0';
1636 					strlcpy(utsname()->domainname, dp,
1637 						sizeof(utsname()->domainname));
1638 				}
1639 				strlcpy(utsname()->nodename, ip,
1640 					sizeof(utsname()->nodename));
1641 				ic_host_name_set = 1;
1642 				break;
1643 			case 5:
1644 				strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1645 				break;
1646 			case 6:
1647 				if (ic_proto_name(ip) == 0 &&
1648 				    ic_myaddr == NONE) {
1649 					ic_enable = 0;
1650 				}
1651 				break;
1652 			case 7:
1653 				if (CONF_NAMESERVERS_MAX >= 1) {
1654 					ic_nameservers[0] = in_aton(ip);
1655 					if (ic_nameservers[0] == ANY)
1656 						ic_nameservers[0] = NONE;
1657 				}
1658 				break;
1659 			case 8:
1660 				if (CONF_NAMESERVERS_MAX >= 2) {
1661 					ic_nameservers[1] = in_aton(ip);
1662 					if (ic_nameservers[1] == ANY)
1663 						ic_nameservers[1] = NONE;
1664 				}
1665 				break;
1666 			}
1667 		}
1668 		ip = cp;
1669 		num++;
1670 	}
1671 
1672 	return 1;
1673 }
1674 __setup("ip=", ip_auto_config_setup);
1675 
1676 static int __init nfsaddrs_config_setup(char *addrs)
1677 {
1678 	return ip_auto_config_setup(addrs);
1679 }
1680 __setup("nfsaddrs=", nfsaddrs_config_setup);
1681 
1682 static int __init vendor_class_identifier_setup(char *addrs)
1683 {
1684 	if (strlcpy(vendor_class_identifier, addrs,
1685 		    sizeof(vendor_class_identifier))
1686 	    >= sizeof(vendor_class_identifier))
1687 		pr_warn("DHCP: vendorclass too long, truncated to \"%s\"",
1688 			vendor_class_identifier);
1689 	return 1;
1690 }
1691 __setup("dhcpclass=", vendor_class_identifier_setup);
1692