xref: /openbmc/linux/net/ipv4/ipconfig.c (revision b78412b8)
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/dsa.h>
61 #include <net/ip.h>
62 #include <net/ipconfig.h>
63 #include <net/route.h>
64 
65 #include <linux/uaccess.h>
66 #include <net/checksum.h>
67 #include <asm/processor.h>
68 
69 #if defined(CONFIG_IP_PNP_DHCP)
70 #define IPCONFIG_DHCP
71 #endif
72 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
73 #define IPCONFIG_BOOTP
74 #endif
75 #if defined(CONFIG_IP_PNP_RARP)
76 #define IPCONFIG_RARP
77 #endif
78 #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
79 #define IPCONFIG_DYNAMIC
80 #endif
81 
82 /* Define the friendly delay before and after opening net devices */
83 #define CONF_POST_OPEN		10	/* After opening: 10 msecs */
84 #define CONF_CARRIER_TIMEOUT	120000	/* Wait for carrier timeout */
85 
86 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
87 #define CONF_OPEN_RETRIES 	2	/* (Re)open devices twice */
88 #define CONF_SEND_RETRIES 	6	/* Send six requests per open */
89 #define CONF_BASE_TIMEOUT	(HZ*2)	/* Initial timeout: 2 seconds */
90 #define CONF_TIMEOUT_RANDOM	(HZ)	/* Maximum amount of randomization */
91 #define CONF_TIMEOUT_MULT	*7/4	/* Rate of timeout growth */
92 #define CONF_TIMEOUT_MAX	(HZ*30)	/* Maximum allowed timeout */
93 #define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
94 					   - '3' from resolv.h */
95 
96 #define NONE cpu_to_be32(INADDR_NONE)
97 #define ANY cpu_to_be32(INADDR_ANY)
98 
99 /*
100  * Public IP configuration
101  */
102 
103 /* This is used by platforms which might be able to set the ipconfig
104  * variables using firmware environment vars.  If this is set, it will
105  * ignore such firmware variables.
106  */
107 int ic_set_manually __initdata = 0;		/* IPconfig parameters set manually */
108 
109 static int ic_enable __initdata;		/* IP config enabled? */
110 
111 /* Protocol choice */
112 int ic_proto_enabled __initdata = 0
113 #ifdef IPCONFIG_BOOTP
114 			| IC_BOOTP
115 #endif
116 #ifdef CONFIG_IP_PNP_DHCP
117 			| IC_USE_DHCP
118 #endif
119 #ifdef IPCONFIG_RARP
120 			| IC_RARP
121 #endif
122 			;
123 
124 static int ic_host_name_set __initdata;	/* Host name set by us? */
125 
126 __be32 ic_myaddr = NONE;		/* My IP address */
127 static __be32 ic_netmask = NONE;	/* Netmask for local subnet */
128 __be32 ic_gateway = NONE;	/* Gateway IP address */
129 
130 #ifdef IPCONFIG_DYNAMIC
131 static __be32 ic_addrservaddr = NONE;	/* IP Address of the IP addresses'server */
132 #endif
133 
134 __be32 ic_servaddr = NONE;	/* Boot server IP address */
135 
136 __be32 root_server_addr = NONE;	/* Address of NFS server */
137 u8 root_server_path[256] = { 0, };	/* Path to mount as root */
138 
139 /* vendor class identifier */
140 static char vendor_class_identifier[253] __initdata;
141 
142 #if defined(CONFIG_IP_PNP_DHCP)
143 static char dhcp_client_identifier[253] __initdata;
144 #endif
145 
146 /* Persistent data: */
147 
148 #ifdef IPCONFIG_DYNAMIC
149 static int ic_proto_used;			/* Protocol used, if any */
150 #else
151 #define ic_proto_used 0
152 #endif
153 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
154 static u8 ic_domain[64];		/* DNS (not NIS) domain name */
155 
156 /*
157  * Private state.
158  */
159 
160 /* Name of user-selected boot device */
161 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
162 
163 /* Protocols supported by available interfaces */
164 static int ic_proto_have_if __initdata;
165 
166 /* MTU for boot device */
167 static int ic_dev_mtu __initdata;
168 
169 #ifdef IPCONFIG_DYNAMIC
170 static DEFINE_SPINLOCK(ic_recv_lock);
171 static volatile int ic_got_reply __initdata;    /* Proto(s) that replied */
172 #endif
173 #ifdef IPCONFIG_DHCP
174 static int ic_dhcp_msgtype __initdata;	/* DHCP msg type received */
175 #endif
176 
177 
178 /*
179  *	Network devices
180  */
181 
182 struct ic_device {
183 	struct ic_device *next;
184 	struct net_device *dev;
185 	unsigned short flags;
186 	short able;
187 	__be32 xid;
188 };
189 
190 static struct ic_device *ic_first_dev __initdata;	/* List of open device */
191 static struct ic_device *ic_dev __initdata;		/* Selected device */
192 
193 static bool __init ic_is_init_dev(struct net_device *dev)
194 {
195 	if (dev->flags & IFF_LOOPBACK)
196 		return false;
197 	return user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
198 	    (!(dev->flags & IFF_LOOPBACK) &&
199 	     (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
200 	     strncmp(dev->name, "dummy", 5));
201 }
202 
203 static int __init ic_open_devs(void)
204 {
205 	struct ic_device *d, **last;
206 	struct net_device *dev;
207 	unsigned short oflags;
208 	unsigned long start, next_msg;
209 
210 	last = &ic_first_dev;
211 	rtnl_lock();
212 
213 	/* bring loopback and DSA master network devices up first */
214 	for_each_netdev(&init_net, dev) {
215 		if (!(dev->flags & IFF_LOOPBACK) && !netdev_uses_dsa(dev))
216 			continue;
217 		if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
218 			pr_err("IP-Config: Failed to open %s\n", dev->name);
219 	}
220 
221 	for_each_netdev(&init_net, dev) {
222 		if (ic_is_init_dev(dev)) {
223 			int able = 0;
224 			if (dev->mtu >= 364)
225 				able |= IC_BOOTP;
226 			else
227 				pr_warn("DHCP/BOOTP: Ignoring device %s, MTU %d too small\n",
228 					dev->name, dev->mtu);
229 			if (!(dev->flags & IFF_NOARP))
230 				able |= IC_RARP;
231 			able &= ic_proto_enabled;
232 			if (ic_proto_enabled && !able)
233 				continue;
234 			oflags = dev->flags;
235 			if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
236 				pr_err("IP-Config: Failed to open %s\n",
237 				       dev->name);
238 				continue;
239 			}
240 			if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
241 				rtnl_unlock();
242 				return -ENOMEM;
243 			}
244 			d->dev = dev;
245 			*last = d;
246 			last = &d->next;
247 			d->flags = oflags;
248 			d->able = able;
249 			if (able & IC_BOOTP)
250 				get_random_bytes(&d->xid, sizeof(__be32));
251 			else
252 				d->xid = 0;
253 			ic_proto_have_if |= able;
254 			pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n",
255 				 dev->name, able, d->xid);
256 		}
257 	}
258 
259 	/* no point in waiting if we could not bring up at least one device */
260 	if (!ic_first_dev)
261 		goto have_carrier;
262 
263 	/* wait for a carrier on at least one device */
264 	start = jiffies;
265 	next_msg = start + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
266 	while (time_before(jiffies, start +
267 			   msecs_to_jiffies(CONF_CARRIER_TIMEOUT))) {
268 		int wait, elapsed;
269 
270 		for_each_netdev(&init_net, dev)
271 			if (ic_is_init_dev(dev) && netif_carrier_ok(dev))
272 				goto have_carrier;
273 
274 		msleep(1);
275 
276 		if (time_before(jiffies, next_msg))
277 			continue;
278 
279 		elapsed = jiffies_to_msecs(jiffies - start);
280 		wait = (CONF_CARRIER_TIMEOUT - elapsed + 500)/1000;
281 		pr_info("Waiting up to %d more seconds for network.\n", wait);
282 		next_msg = jiffies + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
283 	}
284 have_carrier:
285 	rtnl_unlock();
286 
287 	*last = NULL;
288 
289 	if (!ic_first_dev) {
290 		if (user_dev_name[0])
291 			pr_err("IP-Config: Device `%s' not found\n",
292 			       user_dev_name);
293 		else
294 			pr_err("IP-Config: No network devices available\n");
295 		return -ENODEV;
296 	}
297 	return 0;
298 }
299 
300 static void __init ic_close_devs(void)
301 {
302 	struct ic_device *d, *next;
303 	struct net_device *dev;
304 
305 	rtnl_lock();
306 	next = ic_first_dev;
307 	while ((d = next)) {
308 		next = d->next;
309 		dev = d->dev;
310 		if (d != ic_dev && !netdev_uses_dsa(dev)) {
311 			pr_debug("IP-Config: Downing %s\n", dev->name);
312 			dev_change_flags(dev, d->flags);
313 		}
314 		kfree(d);
315 	}
316 	rtnl_unlock();
317 }
318 
319 /*
320  *	Interface to various network functions.
321  */
322 
323 static inline void
324 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
325 {
326 	sin->sin_family = AF_INET;
327 	sin->sin_addr.s_addr = addr;
328 	sin->sin_port = port;
329 }
330 
331 static int __init ic_devinet_ioctl(unsigned int cmd, struct ifreq *arg)
332 {
333 	int res;
334 
335 	mm_segment_t oldfs = get_fs();
336 	set_fs(get_ds());
337 	res = devinet_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
338 	set_fs(oldfs);
339 	return res;
340 }
341 
342 static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
343 {
344 	int res;
345 
346 	mm_segment_t oldfs = get_fs();
347 	set_fs(get_ds());
348 	res = dev_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
349 	set_fs(oldfs);
350 	return res;
351 }
352 
353 static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg)
354 {
355 	int res;
356 
357 	mm_segment_t oldfs = get_fs();
358 	set_fs(get_ds());
359 	res = ip_rt_ioctl(&init_net, cmd, (void __user *) arg);
360 	set_fs(oldfs);
361 	return res;
362 }
363 
364 /*
365  *	Set up interface addresses and routes.
366  */
367 
368 static int __init ic_setup_if(void)
369 {
370 	struct ifreq ir;
371 	struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
372 	int err;
373 
374 	memset(&ir, 0, sizeof(ir));
375 	strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name);
376 	set_sockaddr(sin, ic_myaddr, 0);
377 	if ((err = ic_devinet_ioctl(SIOCSIFADDR, &ir)) < 0) {
378 		pr_err("IP-Config: Unable to set interface address (%d)\n",
379 		       err);
380 		return -1;
381 	}
382 	set_sockaddr(sin, ic_netmask, 0);
383 	if ((err = ic_devinet_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
384 		pr_err("IP-Config: Unable to set interface netmask (%d)\n",
385 		       err);
386 		return -1;
387 	}
388 	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
389 	if ((err = ic_devinet_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
390 		pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
391 		       err);
392 		return -1;
393 	}
394 	/* Handle the case where we need non-standard MTU on the boot link (a network
395 	 * using jumbo frames, for instance).  If we can't set the mtu, don't error
396 	 * out, we'll try to muddle along.
397 	 */
398 	if (ic_dev_mtu != 0) {
399 		strcpy(ir.ifr_name, ic_dev->dev->name);
400 		ir.ifr_mtu = ic_dev_mtu;
401 		if ((err = ic_dev_ioctl(SIOCSIFMTU, &ir)) < 0)
402 			pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
403 			       ic_dev_mtu, err);
404 	}
405 	return 0;
406 }
407 
408 static int __init ic_setup_routes(void)
409 {
410 	/* No need to setup device routes, only the default route... */
411 
412 	if (ic_gateway != NONE) {
413 		struct rtentry rm;
414 		int err;
415 
416 		memset(&rm, 0, sizeof(rm));
417 		if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
418 			pr_err("IP-Config: Gateway not on directly connected network\n");
419 			return -1;
420 		}
421 		set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
422 		set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
423 		set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
424 		rm.rt_flags = RTF_UP | RTF_GATEWAY;
425 		if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) {
426 			pr_err("IP-Config: Cannot add default route (%d)\n",
427 			       err);
428 			return -1;
429 		}
430 	}
431 
432 	return 0;
433 }
434 
435 /*
436  *	Fill in default values for all missing parameters.
437  */
438 
439 static int __init ic_defaults(void)
440 {
441 	/*
442 	 *	At this point we have no userspace running so need not
443 	 *	claim locks on system_utsname
444 	 */
445 
446 	if (!ic_host_name_set)
447 		sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
448 
449 	if (root_server_addr == NONE)
450 		root_server_addr = ic_servaddr;
451 
452 	if (ic_netmask == NONE) {
453 		if (IN_CLASSA(ntohl(ic_myaddr)))
454 			ic_netmask = htonl(IN_CLASSA_NET);
455 		else if (IN_CLASSB(ntohl(ic_myaddr)))
456 			ic_netmask = htonl(IN_CLASSB_NET);
457 		else if (IN_CLASSC(ntohl(ic_myaddr)))
458 			ic_netmask = htonl(IN_CLASSC_NET);
459 		else {
460 			pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
461 			       &ic_myaddr);
462 			return -1;
463 		}
464 		pr_notice("IP-Config: Guessing netmask %pI4\n",
465 			  &ic_netmask);
466 	}
467 
468 	return 0;
469 }
470 
471 /*
472  *	RARP support.
473  */
474 
475 #ifdef IPCONFIG_RARP
476 
477 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
478 
479 static struct packet_type rarp_packet_type __initdata = {
480 	.type =	cpu_to_be16(ETH_P_RARP),
481 	.func =	ic_rarp_recv,
482 };
483 
484 static inline void __init ic_rarp_init(void)
485 {
486 	dev_add_pack(&rarp_packet_type);
487 }
488 
489 static inline void __init ic_rarp_cleanup(void)
490 {
491 	dev_remove_pack(&rarp_packet_type);
492 }
493 
494 /*
495  *  Process received RARP packet.
496  */
497 static int __init
498 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
499 {
500 	struct arphdr *rarp;
501 	unsigned char *rarp_ptr;
502 	__be32 sip, tip;
503 	unsigned char *tha;		/* t for "target" */
504 	struct ic_device *d;
505 
506 	if (!net_eq(dev_net(dev), &init_net))
507 		goto drop;
508 
509 	skb = skb_share_check(skb, GFP_ATOMIC);
510 	if (!skb)
511 		return NET_RX_DROP;
512 
513 	if (!pskb_may_pull(skb, sizeof(struct arphdr)))
514 		goto drop;
515 
516 	/* Basic sanity checks can be done without the lock.  */
517 	rarp = (struct arphdr *)skb_transport_header(skb);
518 
519 	/* If this test doesn't pass, it's not IP, or we should
520 	 * ignore it anyway.
521 	 */
522 	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
523 		goto drop;
524 
525 	/* If it's not a RARP reply, delete it. */
526 	if (rarp->ar_op != htons(ARPOP_RREPLY))
527 		goto drop;
528 
529 	/* If it's not Ethernet, delete it. */
530 	if (rarp->ar_pro != htons(ETH_P_IP))
531 		goto drop;
532 
533 	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
534 		goto drop;
535 
536 	/* OK, it is all there and looks valid, process... */
537 	rarp = (struct arphdr *)skb_transport_header(skb);
538 	rarp_ptr = (unsigned char *) (rarp + 1);
539 
540 	/* One reply at a time, please. */
541 	spin_lock(&ic_recv_lock);
542 
543 	/* If we already have a reply, just drop the packet */
544 	if (ic_got_reply)
545 		goto drop_unlock;
546 
547 	/* Find the ic_device that the packet arrived on */
548 	d = ic_first_dev;
549 	while (d && d->dev != dev)
550 		d = d->next;
551 	if (!d)
552 		goto drop_unlock;	/* should never happen */
553 
554 	/* Extract variable-width fields */
555 	rarp_ptr += dev->addr_len;
556 	memcpy(&sip, rarp_ptr, 4);
557 	rarp_ptr += 4;
558 	tha = rarp_ptr;
559 	rarp_ptr += dev->addr_len;
560 	memcpy(&tip, rarp_ptr, 4);
561 
562 	/* Discard packets which are not meant for us. */
563 	if (memcmp(tha, dev->dev_addr, dev->addr_len))
564 		goto drop_unlock;
565 
566 	/* Discard packets which are not from specified server. */
567 	if (ic_servaddr != NONE && ic_servaddr != sip)
568 		goto drop_unlock;
569 
570 	/* We have a winner! */
571 	ic_dev = d;
572 	if (ic_myaddr == NONE)
573 		ic_myaddr = tip;
574 	ic_servaddr = sip;
575 	ic_addrservaddr = sip;
576 	ic_got_reply = IC_RARP;
577 
578 drop_unlock:
579 	/* Show's over.  Nothing to see here.  */
580 	spin_unlock(&ic_recv_lock);
581 
582 drop:
583 	/* Throw the packet out. */
584 	kfree_skb(skb);
585 	return 0;
586 }
587 
588 
589 /*
590  *  Send RARP request packet over a single interface.
591  */
592 static void __init ic_rarp_send_if(struct ic_device *d)
593 {
594 	struct net_device *dev = d->dev;
595 	arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
596 		 dev->dev_addr, dev->dev_addr);
597 }
598 #endif
599 
600 /*
601  *  Predefine Nameservers
602  */
603 static inline void __init ic_nameservers_predef(void)
604 {
605 	int i;
606 
607 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
608 		ic_nameservers[i] = NONE;
609 }
610 
611 /*
612  *	DHCP/BOOTP support.
613  */
614 
615 #ifdef IPCONFIG_BOOTP
616 
617 struct bootp_pkt {		/* BOOTP packet format */
618 	struct iphdr iph;	/* IP header */
619 	struct udphdr udph;	/* UDP header */
620 	u8 op;			/* 1=request, 2=reply */
621 	u8 htype;		/* HW address type */
622 	u8 hlen;		/* HW address length */
623 	u8 hops;		/* Used only by gateways */
624 	__be32 xid;		/* Transaction ID */
625 	__be16 secs;		/* Seconds since we started */
626 	__be16 flags;		/* Just what it says */
627 	__be32 client_ip;		/* Client's IP address if known */
628 	__be32 your_ip;		/* Assigned IP address */
629 	__be32 server_ip;		/* (Next, e.g. NFS) Server's IP address */
630 	__be32 relay_ip;		/* IP address of BOOTP relay */
631 	u8 hw_addr[16];		/* Client's HW address */
632 	u8 serv_name[64];	/* Server host name */
633 	u8 boot_file[128];	/* Name of boot file */
634 	u8 exten[312];		/* DHCP options / BOOTP vendor extensions */
635 };
636 
637 /* packet ops */
638 #define BOOTP_REQUEST	1
639 #define BOOTP_REPLY	2
640 
641 /* DHCP message types */
642 #define DHCPDISCOVER	1
643 #define DHCPOFFER	2
644 #define DHCPREQUEST	3
645 #define DHCPDECLINE	4
646 #define DHCPACK		5
647 #define DHCPNAK		6
648 #define DHCPRELEASE	7
649 #define DHCPINFORM	8
650 
651 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
652 
653 static struct packet_type bootp_packet_type __initdata = {
654 	.type =	cpu_to_be16(ETH_P_IP),
655 	.func =	ic_bootp_recv,
656 };
657 
658 /*
659  *  Initialize DHCP/BOOTP extension fields in the request.
660  */
661 
662 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
663 
664 #ifdef IPCONFIG_DHCP
665 
666 static void __init
667 ic_dhcp_init_options(u8 *options, struct ic_device *d)
668 {
669 	u8 mt = ((ic_servaddr == NONE)
670 		 ? DHCPDISCOVER : DHCPREQUEST);
671 	u8 *e = options;
672 	int len;
673 
674 	pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
675 
676 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
677 	e += 4;
678 
679 	*e++ = 53;		/* DHCP message type */
680 	*e++ = 1;
681 	*e++ = mt;
682 
683 	if (mt == DHCPREQUEST) {
684 		*e++ = 54;	/* Server ID (IP address) */
685 		*e++ = 4;
686 		memcpy(e, &ic_servaddr, 4);
687 		e += 4;
688 
689 		*e++ = 50;	/* Requested IP address */
690 		*e++ = 4;
691 		memcpy(e, &ic_myaddr, 4);
692 		e += 4;
693 	}
694 
695 	/* always? */
696 	{
697 		static const u8 ic_req_params[] = {
698 			1,	/* Subnet mask */
699 			3,	/* Default gateway */
700 			6,	/* DNS server */
701 			12,	/* Host name */
702 			15,	/* Domain name */
703 			17,	/* Boot path */
704 			26,	/* MTU */
705 			40,	/* NIS domain name */
706 		};
707 
708 		*e++ = 55;	/* Parameter request list */
709 		*e++ = sizeof(ic_req_params);
710 		memcpy(e, ic_req_params, sizeof(ic_req_params));
711 		e += sizeof(ic_req_params);
712 
713 		if (ic_host_name_set) {
714 			*e++ = 12;	/* host-name */
715 			len = strlen(utsname()->nodename);
716 			*e++ = len;
717 			memcpy(e, utsname()->nodename, len);
718 			e += len;
719 		}
720 		if (*vendor_class_identifier) {
721 			pr_info("DHCP: sending class identifier \"%s\"\n",
722 				vendor_class_identifier);
723 			*e++ = 60;	/* Class-identifier */
724 			len = strlen(vendor_class_identifier);
725 			*e++ = len;
726 			memcpy(e, vendor_class_identifier, len);
727 			e += len;
728 		}
729 		len = strlen(dhcp_client_identifier + 1);
730 		/* the minimum length of identifier is 2, include 1 byte type,
731 		 * and can not be larger than the length of options
732 		 */
733 		if (len >= 1 && len < 312 - (e - options) - 1) {
734 			*e++ = 61;
735 			*e++ = len + 1;
736 			memcpy(e, dhcp_client_identifier, len + 1);
737 			e += len + 1;
738 		}
739 	}
740 
741 	*e++ = 255;	/* End of the list */
742 }
743 
744 #endif /* IPCONFIG_DHCP */
745 
746 static void __init ic_bootp_init_ext(u8 *e)
747 {
748 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
749 	e += 4;
750 	*e++ = 1;		/* Subnet mask request */
751 	*e++ = 4;
752 	e += 4;
753 	*e++ = 3;		/* Default gateway request */
754 	*e++ = 4;
755 	e += 4;
756 	*e++ = 5;		/* Name server request */
757 	*e++ = 8;
758 	e += 8;
759 	*e++ = 12;		/* Host name request */
760 	*e++ = 32;
761 	e += 32;
762 	*e++ = 40;		/* NIS Domain name request */
763 	*e++ = 32;
764 	e += 32;
765 	*e++ = 17;		/* Boot path */
766 	*e++ = 40;
767 	e += 40;
768 
769 	*e++ = 57;		/* set extension buffer size for reply */
770 	*e++ = 2;
771 	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
772 	*e++ = 150;
773 
774 	*e++ = 255;		/* End of the list */
775 }
776 
777 
778 /*
779  *  Initialize the DHCP/BOOTP mechanism.
780  */
781 static inline void __init ic_bootp_init(void)
782 {
783 	ic_nameservers_predef();
784 
785 	dev_add_pack(&bootp_packet_type);
786 }
787 
788 
789 /*
790  *  DHCP/BOOTP cleanup.
791  */
792 static inline void __init ic_bootp_cleanup(void)
793 {
794 	dev_remove_pack(&bootp_packet_type);
795 }
796 
797 
798 /*
799  *  Send DHCP/BOOTP request to single interface.
800  */
801 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
802 {
803 	struct net_device *dev = d->dev;
804 	struct sk_buff *skb;
805 	struct bootp_pkt *b;
806 	struct iphdr *h;
807 	int hlen = LL_RESERVED_SPACE(dev);
808 	int tlen = dev->needed_tailroom;
809 
810 	/* Allocate packet */
811 	skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
812 			GFP_KERNEL);
813 	if (!skb)
814 		return;
815 	skb_reserve(skb, hlen);
816 	b = skb_put_zero(skb, sizeof(struct bootp_pkt));
817 
818 	/* Construct IP header */
819 	skb_reset_network_header(skb);
820 	h = ip_hdr(skb);
821 	h->version = 4;
822 	h->ihl = 5;
823 	h->tot_len = htons(sizeof(struct bootp_pkt));
824 	h->frag_off = htons(IP_DF);
825 	h->ttl = 64;
826 	h->protocol = IPPROTO_UDP;
827 	h->daddr = htonl(INADDR_BROADCAST);
828 	h->check = ip_fast_csum((unsigned char *) h, h->ihl);
829 
830 	/* Construct UDP header */
831 	b->udph.source = htons(68);
832 	b->udph.dest = htons(67);
833 	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
834 	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
835 
836 	/* Construct DHCP/BOOTP header */
837 	b->op = BOOTP_REQUEST;
838 	if (dev->type < 256) /* check for false types */
839 		b->htype = dev->type;
840 	else if (dev->type == ARPHRD_FDDI)
841 		b->htype = ARPHRD_ETHER;
842 	else {
843 		pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
844 			dev->name);
845 		b->htype = dev->type; /* can cause undefined behavior */
846 	}
847 
848 	/* server_ip and your_ip address are both already zero per RFC2131 */
849 	b->hlen = dev->addr_len;
850 	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
851 	b->secs = htons(jiffies_diff / HZ);
852 	b->xid = d->xid;
853 
854 	/* add DHCP options or BOOTP extensions */
855 #ifdef IPCONFIG_DHCP
856 	if (ic_proto_enabled & IC_USE_DHCP)
857 		ic_dhcp_init_options(b->exten, d);
858 	else
859 #endif
860 		ic_bootp_init_ext(b->exten);
861 
862 	/* Chain packet down the line... */
863 	skb->dev = dev;
864 	skb->protocol = htons(ETH_P_IP);
865 	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
866 			    dev->broadcast, dev->dev_addr, skb->len) < 0) {
867 		kfree_skb(skb);
868 		printk("E");
869 		return;
870 	}
871 
872 	if (dev_queue_xmit(skb) < 0)
873 		printk("E");
874 }
875 
876 
877 /*
878  *  Copy BOOTP-supplied string if not already set.
879  */
880 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
881 {
882 	if (!len)
883 		return 0;
884 	if (len > max-1)
885 		len = max-1;
886 	memcpy(dest, src, len);
887 	dest[len] = '\0';
888 	return 1;
889 }
890 
891 
892 /*
893  *  Process BOOTP extensions.
894  */
895 static void __init ic_do_bootp_ext(u8 *ext)
896 {
897 	u8 servers;
898 	int i;
899 	__be16 mtu;
900 
901 	u8 *c;
902 
903 	pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
904 	for (c=ext+2; c<ext+2+ext[1]; c++)
905 		pr_debug(" %02x", *c);
906 	pr_debug("\n");
907 
908 	switch (*ext++) {
909 	case 1:		/* Subnet mask */
910 		if (ic_netmask == NONE)
911 			memcpy(&ic_netmask, ext+1, 4);
912 		break;
913 	case 3:		/* Default gateway */
914 		if (ic_gateway == NONE)
915 			memcpy(&ic_gateway, ext+1, 4);
916 		break;
917 	case 6:		/* DNS server */
918 		servers= *ext/4;
919 		if (servers > CONF_NAMESERVERS_MAX)
920 			servers = CONF_NAMESERVERS_MAX;
921 		for (i = 0; i < servers; i++) {
922 			if (ic_nameservers[i] == NONE)
923 				memcpy(&ic_nameservers[i], ext+1+4*i, 4);
924 		}
925 		break;
926 	case 12:	/* Host name */
927 		ic_bootp_string(utsname()->nodename, ext+1, *ext,
928 				__NEW_UTS_LEN);
929 		ic_host_name_set = 1;
930 		break;
931 	case 15:	/* Domain name (DNS) */
932 		ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
933 		break;
934 	case 17:	/* Root path */
935 		if (!root_server_path[0])
936 			ic_bootp_string(root_server_path, ext+1, *ext,
937 					sizeof(root_server_path));
938 		break;
939 	case 26:	/* Interface MTU */
940 		memcpy(&mtu, ext+1, sizeof(mtu));
941 		ic_dev_mtu = ntohs(mtu);
942 		break;
943 	case 40:	/* NIS Domain name (_not_ DNS) */
944 		ic_bootp_string(utsname()->domainname, ext+1, *ext,
945 				__NEW_UTS_LEN);
946 		break;
947 	}
948 }
949 
950 
951 /*
952  *  Receive BOOTP reply.
953  */
954 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
955 {
956 	struct bootp_pkt *b;
957 	struct iphdr *h;
958 	struct ic_device *d;
959 	int len, ext_len;
960 
961 	if (!net_eq(dev_net(dev), &init_net))
962 		goto drop;
963 
964 	/* Perform verifications before taking the lock.  */
965 	if (skb->pkt_type == PACKET_OTHERHOST)
966 		goto drop;
967 
968 	skb = skb_share_check(skb, GFP_ATOMIC);
969 	if (!skb)
970 		return NET_RX_DROP;
971 
972 	if (!pskb_may_pull(skb,
973 			   sizeof(struct iphdr) +
974 			   sizeof(struct udphdr)))
975 		goto drop;
976 
977 	b = (struct bootp_pkt *)skb_network_header(skb);
978 	h = &b->iph;
979 
980 	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
981 		goto drop;
982 
983 	/* Fragments are not supported */
984 	if (ip_is_fragment(h)) {
985 		net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
986 		goto drop;
987 	}
988 
989 	if (skb->len < ntohs(h->tot_len))
990 		goto drop;
991 
992 	if (ip_fast_csum((char *) h, h->ihl))
993 		goto drop;
994 
995 	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
996 		goto drop;
997 
998 	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
999 		goto drop;
1000 
1001 	len = ntohs(b->udph.len) - sizeof(struct udphdr);
1002 	ext_len = len - (sizeof(*b) -
1003 			 sizeof(struct iphdr) -
1004 			 sizeof(struct udphdr) -
1005 			 sizeof(b->exten));
1006 	if (ext_len < 0)
1007 		goto drop;
1008 
1009 	/* Ok the front looks good, make sure we can get at the rest.  */
1010 	if (!pskb_may_pull(skb, skb->len))
1011 		goto drop;
1012 
1013 	b = (struct bootp_pkt *)skb_network_header(skb);
1014 	h = &b->iph;
1015 
1016 	/* One reply at a time, please. */
1017 	spin_lock(&ic_recv_lock);
1018 
1019 	/* If we already have a reply, just drop the packet */
1020 	if (ic_got_reply)
1021 		goto drop_unlock;
1022 
1023 	/* Find the ic_device that the packet arrived on */
1024 	d = ic_first_dev;
1025 	while (d && d->dev != dev)
1026 		d = d->next;
1027 	if (!d)
1028 		goto drop_unlock;  /* should never happen */
1029 
1030 	/* Is it a reply to our BOOTP request? */
1031 	if (b->op != BOOTP_REPLY ||
1032 	    b->xid != d->xid) {
1033 		net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1034 				    d->dev->name, b->op, b->xid);
1035 		goto drop_unlock;
1036 	}
1037 
1038 	/* Parse extensions */
1039 	if (ext_len >= 4 &&
1040 	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1041 		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1042 		u8 *ext;
1043 
1044 #ifdef IPCONFIG_DHCP
1045 		if (ic_proto_enabled & IC_USE_DHCP) {
1046 			__be32 server_id = NONE;
1047 			int mt = 0;
1048 
1049 			ext = &b->exten[4];
1050 			while (ext < end && *ext != 0xff) {
1051 				u8 *opt = ext++;
1052 				if (*opt == 0)	/* Padding */
1053 					continue;
1054 				ext += *ext + 1;
1055 				if (ext >= end)
1056 					break;
1057 				switch (*opt) {
1058 				case 53:	/* Message type */
1059 					if (opt[1])
1060 						mt = opt[2];
1061 					break;
1062 				case 54:	/* Server ID (IP address) */
1063 					if (opt[1] >= 4)
1064 						memcpy(&server_id, opt + 2, 4);
1065 					break;
1066 				}
1067 			}
1068 
1069 			pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
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 				pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1083 					 &ic_myaddr, &b->iph.saddr);
1084 				/* The DHCP indicated server address takes
1085 				 * precedence over the bootp header one if
1086 				 * they are different.
1087 				 */
1088 				if ((server_id != NONE) &&
1089 				    (b->server_ip != server_id))
1090 					b->server_ip = ic_servaddr;
1091 				break;
1092 
1093 			case DHCPACK:
1094 				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1095 					goto drop_unlock;
1096 
1097 				/* Yeah! */
1098 				break;
1099 
1100 			default:
1101 				/* Urque.  Forget it*/
1102 				ic_myaddr = NONE;
1103 				ic_servaddr = NONE;
1104 				goto drop_unlock;
1105 			}
1106 
1107 			ic_dhcp_msgtype = mt;
1108 
1109 		}
1110 #endif /* IPCONFIG_DHCP */
1111 
1112 		ext = &b->exten[4];
1113 		while (ext < end && *ext != 0xff) {
1114 			u8 *opt = ext++;
1115 			if (*opt == 0)	/* Padding */
1116 				continue;
1117 			ext += *ext + 1;
1118 			if (ext < end)
1119 				ic_do_bootp_ext(opt);
1120 		}
1121 	}
1122 
1123 	/* We have a winner! */
1124 	ic_dev = d;
1125 	ic_myaddr = b->your_ip;
1126 	ic_servaddr = b->server_ip;
1127 	ic_addrservaddr = b->iph.saddr;
1128 	if (ic_gateway == NONE && b->relay_ip)
1129 		ic_gateway = b->relay_ip;
1130 	if (ic_nameservers[0] == NONE)
1131 		ic_nameservers[0] = ic_servaddr;
1132 	ic_got_reply = IC_BOOTP;
1133 
1134 drop_unlock:
1135 	/* Show's over.  Nothing to see here.  */
1136 	spin_unlock(&ic_recv_lock);
1137 
1138 drop:
1139 	/* Throw the packet out. */
1140 	kfree_skb(skb);
1141 
1142 	return 0;
1143 }
1144 
1145 
1146 #endif
1147 
1148 
1149 /*
1150  *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
1151  */
1152 
1153 #ifdef IPCONFIG_DYNAMIC
1154 
1155 static int __init ic_dynamic(void)
1156 {
1157 	int retries;
1158 	struct ic_device *d;
1159 	unsigned long start_jiffies, timeout, jiff;
1160 	int do_bootp = ic_proto_have_if & IC_BOOTP;
1161 	int do_rarp = ic_proto_have_if & IC_RARP;
1162 
1163 	/*
1164 	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1165 	 * This routine gets only called when some pieces of information
1166 	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1167 	 */
1168 	if (!ic_proto_enabled) {
1169 		pr_err("IP-Config: Incomplete network configuration information\n");
1170 		return -1;
1171 	}
1172 
1173 #ifdef IPCONFIG_BOOTP
1174 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1175 		pr_err("DHCP/BOOTP: No suitable device found\n");
1176 #endif
1177 #ifdef IPCONFIG_RARP
1178 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1179 		pr_err("RARP: No suitable device found\n");
1180 #endif
1181 
1182 	if (!ic_proto_have_if)
1183 		/* Error message already printed */
1184 		return -1;
1185 
1186 	/*
1187 	 * Setup protocols
1188 	 */
1189 #ifdef IPCONFIG_BOOTP
1190 	if (do_bootp)
1191 		ic_bootp_init();
1192 #endif
1193 #ifdef IPCONFIG_RARP
1194 	if (do_rarp)
1195 		ic_rarp_init();
1196 #endif
1197 
1198 	/*
1199 	 * Send requests and wait, until we get an answer. This loop
1200 	 * seems to be a terrible waste of CPU time, but actually there is
1201 	 * only one process running at all, so we don't need to use any
1202 	 * scheduler functions.
1203 	 * [Actually we could now, but the nothing else running note still
1204 	 *  applies.. - AC]
1205 	 */
1206 	pr_notice("Sending %s%s%s requests .",
1207 		  do_bootp
1208 		  ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1209 		  (do_bootp && do_rarp) ? " and " : "",
1210 		  do_rarp ? "RARP" : "");
1211 
1212 	start_jiffies = jiffies;
1213 	d = ic_first_dev;
1214 	retries = CONF_SEND_RETRIES;
1215 	get_random_bytes(&timeout, sizeof(timeout));
1216 	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1217 	for (;;) {
1218 #ifdef IPCONFIG_BOOTP
1219 		if (do_bootp && (d->able & IC_BOOTP))
1220 			ic_bootp_send_if(d, jiffies - start_jiffies);
1221 #endif
1222 #ifdef IPCONFIG_RARP
1223 		if (do_rarp && (d->able & IC_RARP))
1224 			ic_rarp_send_if(d);
1225 #endif
1226 
1227 		if (!d->next) {
1228 			jiff = jiffies + timeout;
1229 			while (time_before(jiffies, jiff) && !ic_got_reply)
1230 				schedule_timeout_uninterruptible(1);
1231 		}
1232 #ifdef IPCONFIG_DHCP
1233 		/* DHCP isn't done until we get a DHCPACK. */
1234 		if ((ic_got_reply & IC_BOOTP) &&
1235 		    (ic_proto_enabled & IC_USE_DHCP) &&
1236 		    ic_dhcp_msgtype != DHCPACK) {
1237 			ic_got_reply = 0;
1238 			/* continue on device that got the reply */
1239 			d = ic_dev;
1240 			pr_cont(",");
1241 			continue;
1242 		}
1243 #endif /* IPCONFIG_DHCP */
1244 
1245 		if (ic_got_reply) {
1246 			pr_cont(" OK\n");
1247 			break;
1248 		}
1249 
1250 		if ((d = d->next))
1251 			continue;
1252 
1253 		if (! --retries) {
1254 			pr_cont(" timed out!\n");
1255 			break;
1256 		}
1257 
1258 		d = ic_first_dev;
1259 
1260 		timeout = timeout CONF_TIMEOUT_MULT;
1261 		if (timeout > CONF_TIMEOUT_MAX)
1262 			timeout = CONF_TIMEOUT_MAX;
1263 
1264 		pr_cont(".");
1265 	}
1266 
1267 #ifdef IPCONFIG_BOOTP
1268 	if (do_bootp)
1269 		ic_bootp_cleanup();
1270 #endif
1271 #ifdef IPCONFIG_RARP
1272 	if (do_rarp)
1273 		ic_rarp_cleanup();
1274 #endif
1275 
1276 	if (!ic_got_reply) {
1277 		ic_myaddr = NONE;
1278 		return -1;
1279 	}
1280 
1281 	pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1282 		((ic_got_reply & IC_RARP) ? "RARP"
1283 		: (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1284 		&ic_addrservaddr, &ic_myaddr);
1285 
1286 	return 0;
1287 }
1288 
1289 #endif /* IPCONFIG_DYNAMIC */
1290 
1291 #ifdef CONFIG_PROC_FS
1292 
1293 static int pnp_seq_show(struct seq_file *seq, void *v)
1294 {
1295 	int i;
1296 
1297 	if (ic_proto_used & IC_PROTO)
1298 		seq_printf(seq, "#PROTO: %s\n",
1299 			   (ic_proto_used & IC_RARP) ? "RARP"
1300 			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1301 	else
1302 		seq_puts(seq, "#MANUAL\n");
1303 
1304 	if (ic_domain[0])
1305 		seq_printf(seq,
1306 			   "domain %s\n", ic_domain);
1307 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1308 		if (ic_nameservers[i] != NONE)
1309 			seq_printf(seq, "nameserver %pI4\n",
1310 				   &ic_nameservers[i]);
1311 	}
1312 	if (ic_servaddr != NONE)
1313 		seq_printf(seq, "bootserver %pI4\n",
1314 			   &ic_servaddr);
1315 	return 0;
1316 }
1317 
1318 static int pnp_seq_open(struct inode *indoe, struct file *file)
1319 {
1320 	return single_open(file, pnp_seq_show, NULL);
1321 }
1322 
1323 static const struct file_operations pnp_seq_fops = {
1324 	.owner		= THIS_MODULE,
1325 	.open		= pnp_seq_open,
1326 	.read		= seq_read,
1327 	.llseek		= seq_lseek,
1328 	.release	= single_release,
1329 };
1330 #endif /* CONFIG_PROC_FS */
1331 
1332 /*
1333  *  Extract IP address from the parameter string if needed. Note that we
1334  *  need to have root_server_addr set _before_ IPConfig gets called as it
1335  *  can override it.
1336  */
1337 __be32 __init root_nfs_parse_addr(char *name)
1338 {
1339 	__be32 addr;
1340 	int octets = 0;
1341 	char *cp, *cq;
1342 
1343 	cp = cq = name;
1344 	while (octets < 4) {
1345 		while (*cp >= '0' && *cp <= '9')
1346 			cp++;
1347 		if (cp == cq || cp - cq > 3)
1348 			break;
1349 		if (*cp == '.' || octets == 3)
1350 			octets++;
1351 		if (octets < 4)
1352 			cp++;
1353 		cq = cp;
1354 	}
1355 	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1356 		if (*cp == ':')
1357 			*cp++ = '\0';
1358 		addr = in_aton(name);
1359 		memmove(name, cp, strlen(cp) + 1);
1360 	} else
1361 		addr = NONE;
1362 
1363 	return addr;
1364 }
1365 
1366 #define DEVICE_WAIT_MAX		12 /* 12 seconds */
1367 
1368 static int __init wait_for_devices(void)
1369 {
1370 	int i;
1371 
1372 	for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1373 		struct net_device *dev;
1374 		int found = 0;
1375 
1376 		rtnl_lock();
1377 		for_each_netdev(&init_net, dev) {
1378 			if (ic_is_init_dev(dev)) {
1379 				found = 1;
1380 				break;
1381 			}
1382 		}
1383 		rtnl_unlock();
1384 		if (found)
1385 			return 0;
1386 		ssleep(1);
1387 	}
1388 	return -ENODEV;
1389 }
1390 
1391 /*
1392  *	IP Autoconfig dispatcher.
1393  */
1394 
1395 static int __init ip_auto_config(void)
1396 {
1397 	__be32 addr;
1398 #ifdef IPCONFIG_DYNAMIC
1399 	int retries = CONF_OPEN_RETRIES;
1400 #endif
1401 	int err;
1402 	unsigned int i;
1403 
1404 #ifdef CONFIG_PROC_FS
1405 	proc_create("pnp", S_IRUGO, init_net.proc_net, &pnp_seq_fops);
1406 #endif /* CONFIG_PROC_FS */
1407 
1408 	if (!ic_enable)
1409 		return 0;
1410 
1411 	pr_debug("IP-Config: Entered.\n");
1412 #ifdef IPCONFIG_DYNAMIC
1413  try_try_again:
1414 #endif
1415 	/* Wait for devices to appear */
1416 	err = wait_for_devices();
1417 	if (err)
1418 		return err;
1419 
1420 	/* Setup all network devices */
1421 	err = ic_open_devs();
1422 	if (err)
1423 		return err;
1424 
1425 	/* Give drivers a chance to settle */
1426 	msleep(CONF_POST_OPEN);
1427 
1428 	/*
1429 	 * If the config information is insufficient (e.g., our IP address or
1430 	 * IP address of the boot server is missing or we have multiple network
1431 	 * interfaces and no default was set), use BOOTP or RARP to get the
1432 	 * missing values.
1433 	 */
1434 	if (ic_myaddr == NONE ||
1435 #ifdef CONFIG_ROOT_NFS
1436 	    (root_server_addr == NONE &&
1437 	     ic_servaddr == NONE &&
1438 	     ROOT_DEV == Root_NFS) ||
1439 #endif
1440 	    ic_first_dev->next) {
1441 #ifdef IPCONFIG_DYNAMIC
1442 		if (ic_dynamic() < 0) {
1443 			ic_close_devs();
1444 
1445 			/*
1446 			 * I don't know why, but sometimes the
1447 			 * eepro100 driver (at least) gets upset and
1448 			 * doesn't work the first time it's opened.
1449 			 * But then if you close it and reopen it, it
1450 			 * works just fine.  So we need to try that at
1451 			 * least once before giving up.
1452 			 *
1453 			 * Also, if the root will be NFS-mounted, we
1454 			 * have nowhere to go if DHCP fails.  So we
1455 			 * just have to keep trying forever.
1456 			 *
1457 			 * 				-- Chip
1458 			 */
1459 #ifdef CONFIG_ROOT_NFS
1460 			if (ROOT_DEV ==  Root_NFS) {
1461 				pr_err("IP-Config: Retrying forever (NFS root)...\n");
1462 				goto try_try_again;
1463 			}
1464 #endif
1465 
1466 			if (--retries) {
1467 				pr_err("IP-Config: Reopening network devices...\n");
1468 				goto try_try_again;
1469 			}
1470 
1471 			/* Oh, well.  At least we tried. */
1472 			pr_err("IP-Config: Auto-configuration of network failed\n");
1473 			return -1;
1474 		}
1475 #else /* !DYNAMIC */
1476 		pr_err("IP-Config: Incomplete network configuration information\n");
1477 		ic_close_devs();
1478 		return -1;
1479 #endif /* IPCONFIG_DYNAMIC */
1480 	} else {
1481 		/* Device selected manually or only one device -> use it */
1482 		ic_dev = ic_first_dev;
1483 	}
1484 
1485 	addr = root_nfs_parse_addr(root_server_path);
1486 	if (root_server_addr == NONE)
1487 		root_server_addr = addr;
1488 
1489 	/*
1490 	 * Use defaults wherever applicable.
1491 	 */
1492 	if (ic_defaults() < 0)
1493 		return -1;
1494 
1495 	/*
1496 	 * Record which protocol was actually used.
1497 	 */
1498 #ifdef IPCONFIG_DYNAMIC
1499 	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1500 #endif
1501 
1502 #ifndef IPCONFIG_SILENT
1503 	/*
1504 	 * Clue in the operator.
1505 	 */
1506 	pr_info("IP-Config: Complete:\n");
1507 
1508 	pr_info("     device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1509 		ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1510 		&ic_myaddr, &ic_netmask, &ic_gateway);
1511 	pr_info("     host=%s, domain=%s, nis-domain=%s\n",
1512 		utsname()->nodename, ic_domain, utsname()->domainname);
1513 	pr_info("     bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1514 		&ic_servaddr, &root_server_addr, root_server_path);
1515 	if (ic_dev_mtu)
1516 		pr_cont(", mtu=%d", ic_dev_mtu);
1517 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
1518 		if (ic_nameservers[i] != NONE) {
1519 			pr_cont("     nameserver%u=%pI4",
1520 				i, &ic_nameservers[i]);
1521 			break;
1522 		}
1523 	for (i++; i < CONF_NAMESERVERS_MAX; i++)
1524 		if (ic_nameservers[i] != NONE)
1525 			pr_cont(", nameserver%u=%pI4", i, &ic_nameservers[i]);
1526 	pr_cont("\n");
1527 #endif /* !SILENT */
1528 
1529 	/*
1530 	 * Close all network devices except the device we've
1531 	 * autoconfigured and set up routes.
1532 	 */
1533 	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1534 		err = -1;
1535 	else
1536 		err = 0;
1537 
1538 	ic_close_devs();
1539 
1540 	return err;
1541 }
1542 
1543 late_initcall(ip_auto_config);
1544 
1545 
1546 /*
1547  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1548  *  command line parameter.  See Documentation/filesystems/nfs/nfsroot.txt.
1549  */
1550 static int __init ic_proto_name(char *name)
1551 {
1552 	if (!strcmp(name, "on") || !strcmp(name, "any")) {
1553 		return 1;
1554 	}
1555 	if (!strcmp(name, "off") || !strcmp(name, "none")) {
1556 		return 0;
1557 	}
1558 #ifdef CONFIG_IP_PNP_DHCP
1559 	else if (!strncmp(name, "dhcp", 4)) {
1560 		char *client_id;
1561 
1562 		ic_proto_enabled &= ~IC_RARP;
1563 		client_id = strstr(name, "dhcp,");
1564 		if (client_id) {
1565 			char *v;
1566 
1567 			client_id = client_id + 5;
1568 			v = strchr(client_id, ',');
1569 			if (!v)
1570 				return 1;
1571 			*v = 0;
1572 			if (kstrtou8(client_id, 0, dhcp_client_identifier))
1573 				pr_debug("DHCP: Invalid client identifier type\n");
1574 			strncpy(dhcp_client_identifier + 1, v + 1, 251);
1575 			*v = ',';
1576 		}
1577 		return 1;
1578 	}
1579 #endif
1580 #ifdef CONFIG_IP_PNP_BOOTP
1581 	else if (!strcmp(name, "bootp")) {
1582 		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1583 		return 1;
1584 	}
1585 #endif
1586 #ifdef CONFIG_IP_PNP_RARP
1587 	else if (!strcmp(name, "rarp")) {
1588 		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1589 		return 1;
1590 	}
1591 #endif
1592 #ifdef IPCONFIG_DYNAMIC
1593 	else if (!strcmp(name, "both")) {
1594 		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1595 		return 1;
1596 	}
1597 #endif
1598 	return 0;
1599 }
1600 
1601 static int __init ip_auto_config_setup(char *addrs)
1602 {
1603 	char *cp, *ip, *dp;
1604 	int num = 0;
1605 
1606 	ic_set_manually = 1;
1607 	ic_enable = 1;
1608 
1609 	/*
1610 	 * If any dhcp, bootp etc options are set, leave autoconfig on
1611 	 * and skip the below static IP processing.
1612 	 */
1613 	if (ic_proto_name(addrs))
1614 		return 1;
1615 
1616 	/* If no static IP is given, turn off autoconfig and bail.  */
1617 	if (*addrs == 0 ||
1618 	    strcmp(addrs, "off") == 0 ||
1619 	    strcmp(addrs, "none") == 0) {
1620 		ic_enable = 0;
1621 		return 1;
1622 	}
1623 
1624 	ic_nameservers_predef();
1625 
1626 	/* Parse string for static IP assignment.  */
1627 	ip = addrs;
1628 	while (ip && *ip) {
1629 		if ((cp = strchr(ip, ':')))
1630 			*cp++ = '\0';
1631 		if (strlen(ip) > 0) {
1632 			pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1633 			switch (num) {
1634 			case 0:
1635 				if ((ic_myaddr = in_aton(ip)) == ANY)
1636 					ic_myaddr = NONE;
1637 				break;
1638 			case 1:
1639 				if ((ic_servaddr = in_aton(ip)) == ANY)
1640 					ic_servaddr = NONE;
1641 				break;
1642 			case 2:
1643 				if ((ic_gateway = in_aton(ip)) == ANY)
1644 					ic_gateway = NONE;
1645 				break;
1646 			case 3:
1647 				if ((ic_netmask = in_aton(ip)) == ANY)
1648 					ic_netmask = NONE;
1649 				break;
1650 			case 4:
1651 				if ((dp = strchr(ip, '.'))) {
1652 					*dp++ = '\0';
1653 					strlcpy(utsname()->domainname, dp,
1654 						sizeof(utsname()->domainname));
1655 				}
1656 				strlcpy(utsname()->nodename, ip,
1657 					sizeof(utsname()->nodename));
1658 				ic_host_name_set = 1;
1659 				break;
1660 			case 5:
1661 				strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1662 				break;
1663 			case 6:
1664 				if (ic_proto_name(ip) == 0 &&
1665 				    ic_myaddr == NONE) {
1666 					ic_enable = 0;
1667 				}
1668 				break;
1669 			case 7:
1670 				if (CONF_NAMESERVERS_MAX >= 1) {
1671 					ic_nameservers[0] = in_aton(ip);
1672 					if (ic_nameservers[0] == ANY)
1673 						ic_nameservers[0] = NONE;
1674 				}
1675 				break;
1676 			case 8:
1677 				if (CONF_NAMESERVERS_MAX >= 2) {
1678 					ic_nameservers[1] = in_aton(ip);
1679 					if (ic_nameservers[1] == ANY)
1680 						ic_nameservers[1] = NONE;
1681 				}
1682 				break;
1683 			}
1684 		}
1685 		ip = cp;
1686 		num++;
1687 	}
1688 
1689 	return 1;
1690 }
1691 __setup("ip=", ip_auto_config_setup);
1692 
1693 static int __init nfsaddrs_config_setup(char *addrs)
1694 {
1695 	return ip_auto_config_setup(addrs);
1696 }
1697 __setup("nfsaddrs=", nfsaddrs_config_setup);
1698 
1699 static int __init vendor_class_identifier_setup(char *addrs)
1700 {
1701 	if (strlcpy(vendor_class_identifier, addrs,
1702 		    sizeof(vendor_class_identifier))
1703 	    >= sizeof(vendor_class_identifier))
1704 		pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1705 			vendor_class_identifier);
1706 	return 1;
1707 }
1708 __setup("dhcpclass=", vendor_class_identifier_setup);
1709