xref: /linux/net/ipv4/ipconfig.c (revision f412eed9dfdeeb6becd7de2ffe8b5d0a8b3f81ca)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or
4  *  user-supplied information to configure own IP address and routes.
5  *
6  *  Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
7  *
8  *  Derived from network configuration code in fs/nfs/nfsroot.c,
9  *  originally Copyright (C) 1995, 1996 Gero Kuhlmann and me.
10  *
11  *  BOOTP rewritten to construct and analyse packets itself instead
12  *  of misusing the IP layer. num_bugs_causing_wrong_arp_replies--;
13  *					     -- MJ, December 1998
14  *
15  *  Fixed ip_auto_config_setup calling at startup in the new "Linker Magic"
16  *  initialization scheme.
17  *	- Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999
18  *
19  *  DHCP support added.  To users this looks like a whole separate
20  *  protocol, but we know it's just a bag on the side of BOOTP.
21  *		-- Chip Salzenberg <chip@valinux.com>, May 2000
22  *
23  *  Ported DHCP support from 2.2.16 to 2.4.0-test4
24  *              -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000
25  *
26  *  Merged changes from 2.2.19 into 2.4.3
27  *              -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001
28  *
29  *  Multiple Nameservers in /proc/net/pnp
30  *              --  Josef Siemes <jsiemes@web.de>, Aug 2002
31  *
32  *  NTP servers in /proc/net/ipconfig/ntp_servers
33  *              --  Chris Novakovic <chris@chrisn.me.uk>, April 2018
34  */
35 
36 #include <linux/types.h>
37 #include <linux/string.h>
38 #include <linux/kernel.h>
39 #include <linux/jiffies.h>
40 #include <linux/random.h>
41 #include <linux/init.h>
42 #include <linux/utsname.h>
43 #include <linux/in.h>
44 #include <linux/if.h>
45 #include <linux/inet.h>
46 #include <linux/inetdevice.h>
47 #include <linux/netdevice.h>
48 #include <linux/if_arp.h>
49 #include <linux/skbuff.h>
50 #include <linux/ip.h>
51 #include <linux/socket.h>
52 #include <linux/route.h>
53 #include <linux/udp.h>
54 #include <linux/proc_fs.h>
55 #include <linux/seq_file.h>
56 #include <linux/major.h>
57 #include <linux/root_dev.h>
58 #include <linux/delay.h>
59 #include <linux/nfs_fs.h>
60 #include <linux/slab.h>
61 #include <linux/export.h>
62 #include <net/net_namespace.h>
63 #include <net/arp.h>
64 #include <net/dsa.h>
65 #include <net/ip.h>
66 #include <net/ipconfig.h>
67 #include <net/route.h>
68 
69 #include <linux/uaccess.h>
70 #include <net/checksum.h>
71 #include <asm/processor.h>
72 
73 #if defined(CONFIG_IP_PNP_DHCP)
74 #define IPCONFIG_DHCP
75 #endif
76 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
77 #define IPCONFIG_BOOTP
78 #endif
79 #if defined(CONFIG_IP_PNP_RARP)
80 #define IPCONFIG_RARP
81 #endif
82 #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
83 #define IPCONFIG_DYNAMIC
84 #endif
85 
86 /* Define the friendly delay before and after opening net devices */
87 #define CONF_POST_OPEN		10	/* After opening: 10 msecs */
88 #define CONF_CARRIER_TIMEOUT	120000	/* Wait for carrier timeout */
89 
90 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
91 #define CONF_OPEN_RETRIES 	2	/* (Re)open devices twice */
92 #define CONF_SEND_RETRIES 	6	/* Send six requests per open */
93 #define CONF_BASE_TIMEOUT	(HZ*2)	/* Initial timeout: 2 seconds */
94 #define CONF_TIMEOUT_RANDOM	(HZ)	/* Maximum amount of randomization */
95 #define CONF_TIMEOUT_MULT	*7/4	/* Rate of timeout growth */
96 #define CONF_TIMEOUT_MAX	(HZ*30)	/* Maximum allowed timeout */
97 #define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
98 					   - '3' from resolv.h */
99 #define CONF_NTP_SERVERS_MAX   3	/* Maximum number of NTP servers */
100 
101 #define NONE cpu_to_be32(INADDR_NONE)
102 #define ANY cpu_to_be32(INADDR_ANY)
103 
104 /*
105  * Public IP configuration
106  */
107 
108 /* This is used by platforms which might be able to set the ipconfig
109  * variables using firmware environment vars.  If this is set, it will
110  * ignore such firmware variables.
111  */
112 int ic_set_manually __initdata = 0;		/* IPconfig parameters set manually */
113 
114 static int ic_enable __initdata;		/* IP config enabled? */
115 
116 /* Protocol choice */
117 int ic_proto_enabled __initdata = 0
118 #ifdef IPCONFIG_BOOTP
119 			| IC_BOOTP
120 #endif
121 #ifdef CONFIG_IP_PNP_DHCP
122 			| IC_USE_DHCP
123 #endif
124 #ifdef IPCONFIG_RARP
125 			| IC_RARP
126 #endif
127 			;
128 
129 static int ic_host_name_set __initdata;	/* Host name set by us? */
130 
131 __be32 ic_myaddr = NONE;		/* My IP address */
132 static __be32 ic_netmask = NONE;	/* Netmask for local subnet */
133 __be32 ic_gateway = NONE;	/* Gateway IP address */
134 
135 #ifdef IPCONFIG_DYNAMIC
136 static __be32 ic_addrservaddr = NONE;	/* IP Address of the IP addresses'server */
137 #endif
138 
139 __be32 ic_servaddr = NONE;	/* Boot server IP address */
140 
141 __be32 root_server_addr = NONE;	/* Address of NFS server */
142 u8 root_server_path[256] = { 0, };	/* Path to mount as root */
143 
144 /* vendor class identifier */
145 static char vendor_class_identifier[253] __initdata;
146 
147 #if defined(CONFIG_IP_PNP_DHCP)
148 static char dhcp_client_identifier[253] __initdata;
149 #endif
150 
151 /* Persistent data: */
152 
153 #ifdef IPCONFIG_DYNAMIC
154 static int ic_proto_used;			/* Protocol used, if any */
155 #else
156 #define ic_proto_used 0
157 #endif
158 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
159 static __be32 ic_ntp_servers[CONF_NTP_SERVERS_MAX]; /* NTP server IP addresses */
160 static u8 ic_domain[64];		/* DNS (not NIS) domain name */
161 
162 /*
163  * Private state.
164  */
165 
166 /* proc_dir_entry for /proc/net/ipconfig */
167 static struct proc_dir_entry *ipconfig_dir;
168 
169 /* Name of user-selected boot device */
170 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
171 
172 /* Protocols supported by available interfaces */
173 static int ic_proto_have_if __initdata;
174 
175 /* MTU for boot device */
176 static int ic_dev_mtu __initdata;
177 
178 #ifdef IPCONFIG_DYNAMIC
179 static DEFINE_SPINLOCK(ic_recv_lock);
180 static volatile int ic_got_reply __initdata;    /* Proto(s) that replied */
181 #endif
182 #ifdef IPCONFIG_DHCP
183 static int ic_dhcp_msgtype __initdata;	/* DHCP msg type received */
184 #endif
185 
186 
187 /*
188  *	Network devices
189  */
190 
191 struct ic_device {
192 	struct ic_device *next;
193 	struct net_device *dev;
194 	unsigned short flags;
195 	short able;
196 	__be32 xid;
197 };
198 
199 static struct ic_device *ic_first_dev __initdata;	/* List of open device */
200 static struct ic_device *ic_dev __initdata;		/* Selected device */
201 
202 static bool __init ic_is_init_dev(struct net_device *dev)
203 {
204 	if (dev->flags & IFF_LOOPBACK)
205 		return false;
206 	return user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
207 	    (!(dev->flags & IFF_LOOPBACK) &&
208 	     (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
209 	     strncmp(dev->name, "dummy", 5));
210 }
211 
212 static int __init ic_open_devs(void)
213 {
214 	struct ic_device *d, **last;
215 	struct net_device *dev;
216 	unsigned short oflags;
217 	unsigned long start, next_msg;
218 
219 	last = &ic_first_dev;
220 	rtnl_lock();
221 
222 	/* bring loopback and DSA master network devices up first */
223 	for_each_netdev(&init_net, dev) {
224 		if (!(dev->flags & IFF_LOOPBACK) && !netdev_uses_dsa(dev))
225 			continue;
226 		if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
227 			pr_err("IP-Config: Failed to open %s\n", dev->name);
228 	}
229 
230 	for_each_netdev(&init_net, dev) {
231 		if (ic_is_init_dev(dev)) {
232 			int able = 0;
233 			if (dev->mtu >= 364)
234 				able |= IC_BOOTP;
235 			else
236 				pr_warn("DHCP/BOOTP: Ignoring device %s, MTU %d too small\n",
237 					dev->name, dev->mtu);
238 			if (!(dev->flags & IFF_NOARP))
239 				able |= IC_RARP;
240 			able &= ic_proto_enabled;
241 			if (ic_proto_enabled && !able)
242 				continue;
243 			oflags = dev->flags;
244 			if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
245 				pr_err("IP-Config: Failed to open %s\n",
246 				       dev->name);
247 				continue;
248 			}
249 			if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
250 				rtnl_unlock();
251 				return -ENOMEM;
252 			}
253 			d->dev = dev;
254 			*last = d;
255 			last = &d->next;
256 			d->flags = oflags;
257 			d->able = able;
258 			if (able & IC_BOOTP)
259 				get_random_bytes(&d->xid, sizeof(__be32));
260 			else
261 				d->xid = 0;
262 			ic_proto_have_if |= able;
263 			pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n",
264 				 dev->name, able, d->xid);
265 		}
266 	}
267 
268 	/* no point in waiting if we could not bring up at least one device */
269 	if (!ic_first_dev)
270 		goto have_carrier;
271 
272 	/* wait for a carrier on at least one device */
273 	start = jiffies;
274 	next_msg = start + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
275 	while (time_before(jiffies, start +
276 			   msecs_to_jiffies(CONF_CARRIER_TIMEOUT))) {
277 		int wait, elapsed;
278 
279 		for_each_netdev(&init_net, dev)
280 			if (ic_is_init_dev(dev) && netif_carrier_ok(dev))
281 				goto have_carrier;
282 
283 		msleep(1);
284 
285 		if (time_before(jiffies, next_msg))
286 			continue;
287 
288 		elapsed = jiffies_to_msecs(jiffies - start);
289 		wait = (CONF_CARRIER_TIMEOUT - elapsed + 500)/1000;
290 		pr_info("Waiting up to %d more seconds for network.\n", wait);
291 		next_msg = jiffies + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
292 	}
293 have_carrier:
294 	rtnl_unlock();
295 
296 	*last = NULL;
297 
298 	if (!ic_first_dev) {
299 		if (user_dev_name[0])
300 			pr_err("IP-Config: Device `%s' not found\n",
301 			       user_dev_name);
302 		else
303 			pr_err("IP-Config: No network devices available\n");
304 		return -ENODEV;
305 	}
306 	return 0;
307 }
308 
309 static void __init ic_close_devs(void)
310 {
311 	struct ic_device *d, *next;
312 	struct net_device *dev;
313 
314 	rtnl_lock();
315 	next = ic_first_dev;
316 	while ((d = next)) {
317 		next = d->next;
318 		dev = d->dev;
319 		if (d != ic_dev && !netdev_uses_dsa(dev)) {
320 			pr_debug("IP-Config: Downing %s\n", dev->name);
321 			dev_change_flags(dev, d->flags);
322 		}
323 		kfree(d);
324 	}
325 	rtnl_unlock();
326 }
327 
328 /*
329  *	Interface to various network functions.
330  */
331 
332 static inline void
333 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
334 {
335 	sin->sin_family = AF_INET;
336 	sin->sin_addr.s_addr = addr;
337 	sin->sin_port = port;
338 }
339 
340 /*
341  *	Set up interface addresses and routes.
342  */
343 
344 static int __init ic_setup_if(void)
345 {
346 	struct ifreq ir;
347 	struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
348 	int err;
349 
350 	memset(&ir, 0, sizeof(ir));
351 	strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name);
352 	set_sockaddr(sin, ic_myaddr, 0);
353 	if ((err = devinet_ioctl(&init_net, SIOCSIFADDR, &ir)) < 0) {
354 		pr_err("IP-Config: Unable to set interface address (%d)\n",
355 		       err);
356 		return -1;
357 	}
358 	set_sockaddr(sin, ic_netmask, 0);
359 	if ((err = devinet_ioctl(&init_net, SIOCSIFNETMASK, &ir)) < 0) {
360 		pr_err("IP-Config: Unable to set interface netmask (%d)\n",
361 		       err);
362 		return -1;
363 	}
364 	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
365 	if ((err = devinet_ioctl(&init_net, SIOCSIFBRDADDR, &ir)) < 0) {
366 		pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
367 		       err);
368 		return -1;
369 	}
370 	/* Handle the case where we need non-standard MTU on the boot link (a network
371 	 * using jumbo frames, for instance).  If we can't set the mtu, don't error
372 	 * out, we'll try to muddle along.
373 	 */
374 	if (ic_dev_mtu != 0) {
375 		rtnl_lock();
376 		if ((err = dev_set_mtu(ic_dev->dev, ic_dev_mtu)) < 0)
377 			pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
378 			       ic_dev_mtu, err);
379 		rtnl_unlock();
380 	}
381 	return 0;
382 }
383 
384 static int __init ic_setup_routes(void)
385 {
386 	/* No need to setup device routes, only the default route... */
387 
388 	if (ic_gateway != NONE) {
389 		struct rtentry rm;
390 		int err;
391 
392 		memset(&rm, 0, sizeof(rm));
393 		if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
394 			pr_err("IP-Config: Gateway not on directly connected network\n");
395 			return -1;
396 		}
397 		set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
398 		set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
399 		set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
400 		rm.rt_flags = RTF_UP | RTF_GATEWAY;
401 		if ((err = ip_rt_ioctl(&init_net, SIOCADDRT, &rm)) < 0) {
402 			pr_err("IP-Config: Cannot add default route (%d)\n",
403 			       err);
404 			return -1;
405 		}
406 	}
407 
408 	return 0;
409 }
410 
411 /*
412  *	Fill in default values for all missing parameters.
413  */
414 
415 static int __init ic_defaults(void)
416 {
417 	/*
418 	 *	At this point we have no userspace running so need not
419 	 *	claim locks on system_utsname
420 	 */
421 
422 	if (!ic_host_name_set)
423 		sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
424 
425 	if (root_server_addr == NONE)
426 		root_server_addr = ic_servaddr;
427 
428 	if (ic_netmask == NONE) {
429 		if (IN_CLASSA(ntohl(ic_myaddr)))
430 			ic_netmask = htonl(IN_CLASSA_NET);
431 		else if (IN_CLASSB(ntohl(ic_myaddr)))
432 			ic_netmask = htonl(IN_CLASSB_NET);
433 		else if (IN_CLASSC(ntohl(ic_myaddr)))
434 			ic_netmask = htonl(IN_CLASSC_NET);
435 		else {
436 			pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
437 			       &ic_myaddr);
438 			return -1;
439 		}
440 		pr_notice("IP-Config: Guessing netmask %pI4\n",
441 			  &ic_netmask);
442 	}
443 
444 	return 0;
445 }
446 
447 /*
448  *	RARP support.
449  */
450 
451 #ifdef IPCONFIG_RARP
452 
453 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
454 
455 static struct packet_type rarp_packet_type __initdata = {
456 	.type =	cpu_to_be16(ETH_P_RARP),
457 	.func =	ic_rarp_recv,
458 };
459 
460 static inline void __init ic_rarp_init(void)
461 {
462 	dev_add_pack(&rarp_packet_type);
463 }
464 
465 static inline void __init ic_rarp_cleanup(void)
466 {
467 	dev_remove_pack(&rarp_packet_type);
468 }
469 
470 /*
471  *  Process received RARP packet.
472  */
473 static int __init
474 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
475 {
476 	struct arphdr *rarp;
477 	unsigned char *rarp_ptr;
478 	__be32 sip, tip;
479 	unsigned char *tha;		/* t for "target" */
480 	struct ic_device *d;
481 
482 	if (!net_eq(dev_net(dev), &init_net))
483 		goto drop;
484 
485 	skb = skb_share_check(skb, GFP_ATOMIC);
486 	if (!skb)
487 		return NET_RX_DROP;
488 
489 	if (!pskb_may_pull(skb, sizeof(struct arphdr)))
490 		goto drop;
491 
492 	/* Basic sanity checks can be done without the lock.  */
493 	rarp = (struct arphdr *)skb_transport_header(skb);
494 
495 	/* If this test doesn't pass, it's not IP, or we should
496 	 * ignore it anyway.
497 	 */
498 	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
499 		goto drop;
500 
501 	/* If it's not a RARP reply, delete it. */
502 	if (rarp->ar_op != htons(ARPOP_RREPLY))
503 		goto drop;
504 
505 	/* If it's not Ethernet, delete it. */
506 	if (rarp->ar_pro != htons(ETH_P_IP))
507 		goto drop;
508 
509 	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
510 		goto drop;
511 
512 	/* OK, it is all there and looks valid, process... */
513 	rarp = (struct arphdr *)skb_transport_header(skb);
514 	rarp_ptr = (unsigned char *) (rarp + 1);
515 
516 	/* One reply at a time, please. */
517 	spin_lock(&ic_recv_lock);
518 
519 	/* If we already have a reply, just drop the packet */
520 	if (ic_got_reply)
521 		goto drop_unlock;
522 
523 	/* Find the ic_device that the packet arrived on */
524 	d = ic_first_dev;
525 	while (d && d->dev != dev)
526 		d = d->next;
527 	if (!d)
528 		goto drop_unlock;	/* should never happen */
529 
530 	/* Extract variable-width fields */
531 	rarp_ptr += dev->addr_len;
532 	memcpy(&sip, rarp_ptr, 4);
533 	rarp_ptr += 4;
534 	tha = rarp_ptr;
535 	rarp_ptr += dev->addr_len;
536 	memcpy(&tip, rarp_ptr, 4);
537 
538 	/* Discard packets which are not meant for us. */
539 	if (memcmp(tha, dev->dev_addr, dev->addr_len))
540 		goto drop_unlock;
541 
542 	/* Discard packets which are not from specified server. */
543 	if (ic_servaddr != NONE && ic_servaddr != sip)
544 		goto drop_unlock;
545 
546 	/* We have a winner! */
547 	ic_dev = d;
548 	if (ic_myaddr == NONE)
549 		ic_myaddr = tip;
550 	ic_servaddr = sip;
551 	ic_addrservaddr = sip;
552 	ic_got_reply = IC_RARP;
553 
554 drop_unlock:
555 	/* Show's over.  Nothing to see here.  */
556 	spin_unlock(&ic_recv_lock);
557 
558 drop:
559 	/* Throw the packet out. */
560 	kfree_skb(skb);
561 	return 0;
562 }
563 
564 
565 /*
566  *  Send RARP request packet over a single interface.
567  */
568 static void __init ic_rarp_send_if(struct ic_device *d)
569 {
570 	struct net_device *dev = d->dev;
571 	arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
572 		 dev->dev_addr, dev->dev_addr);
573 }
574 #endif
575 
576 /*
577  *  Predefine Nameservers
578  */
579 static inline void __init ic_nameservers_predef(void)
580 {
581 	int i;
582 
583 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
584 		ic_nameservers[i] = NONE;
585 }
586 
587 /* Predefine NTP servers */
588 static inline void __init ic_ntp_servers_predef(void)
589 {
590 	int i;
591 
592 	for (i = 0; i < CONF_NTP_SERVERS_MAX; i++)
593 		ic_ntp_servers[i] = NONE;
594 }
595 
596 /*
597  *	DHCP/BOOTP support.
598  */
599 
600 #ifdef IPCONFIG_BOOTP
601 
602 struct bootp_pkt {		/* BOOTP packet format */
603 	struct iphdr iph;	/* IP header */
604 	struct udphdr udph;	/* UDP header */
605 	u8 op;			/* 1=request, 2=reply */
606 	u8 htype;		/* HW address type */
607 	u8 hlen;		/* HW address length */
608 	u8 hops;		/* Used only by gateways */
609 	__be32 xid;		/* Transaction ID */
610 	__be16 secs;		/* Seconds since we started */
611 	__be16 flags;		/* Just what it says */
612 	__be32 client_ip;		/* Client's IP address if known */
613 	__be32 your_ip;		/* Assigned IP address */
614 	__be32 server_ip;		/* (Next, e.g. NFS) Server's IP address */
615 	__be32 relay_ip;		/* IP address of BOOTP relay */
616 	u8 hw_addr[16];		/* Client's HW address */
617 	u8 serv_name[64];	/* Server host name */
618 	u8 boot_file[128];	/* Name of boot file */
619 	u8 exten[312];		/* DHCP options / BOOTP vendor extensions */
620 };
621 
622 /* packet ops */
623 #define BOOTP_REQUEST	1
624 #define BOOTP_REPLY	2
625 
626 /* DHCP message types */
627 #define DHCPDISCOVER	1
628 #define DHCPOFFER	2
629 #define DHCPREQUEST	3
630 #define DHCPDECLINE	4
631 #define DHCPACK		5
632 #define DHCPNAK		6
633 #define DHCPRELEASE	7
634 #define DHCPINFORM	8
635 
636 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
637 
638 static struct packet_type bootp_packet_type __initdata = {
639 	.type =	cpu_to_be16(ETH_P_IP),
640 	.func =	ic_bootp_recv,
641 };
642 
643 /*
644  *  Initialize DHCP/BOOTP extension fields in the request.
645  */
646 
647 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
648 
649 #ifdef IPCONFIG_DHCP
650 
651 static void __init
652 ic_dhcp_init_options(u8 *options, struct ic_device *d)
653 {
654 	u8 mt = ((ic_servaddr == NONE)
655 		 ? DHCPDISCOVER : DHCPREQUEST);
656 	u8 *e = options;
657 	int len;
658 
659 	pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
660 
661 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
662 	e += 4;
663 
664 	*e++ = 53;		/* DHCP message type */
665 	*e++ = 1;
666 	*e++ = mt;
667 
668 	if (mt == DHCPREQUEST) {
669 		*e++ = 54;	/* Server ID (IP address) */
670 		*e++ = 4;
671 		memcpy(e, &ic_servaddr, 4);
672 		e += 4;
673 
674 		*e++ = 50;	/* Requested IP address */
675 		*e++ = 4;
676 		memcpy(e, &ic_myaddr, 4);
677 		e += 4;
678 	}
679 
680 	/* always? */
681 	{
682 		static const u8 ic_req_params[] = {
683 			1,	/* Subnet mask */
684 			3,	/* Default gateway */
685 			6,	/* DNS server */
686 			12,	/* Host name */
687 			15,	/* Domain name */
688 			17,	/* Boot path */
689 			26,	/* MTU */
690 			40,	/* NIS domain name */
691 			42,	/* NTP servers */
692 		};
693 
694 		*e++ = 55;	/* Parameter request list */
695 		*e++ = sizeof(ic_req_params);
696 		memcpy(e, ic_req_params, sizeof(ic_req_params));
697 		e += sizeof(ic_req_params);
698 
699 		if (ic_host_name_set) {
700 			*e++ = 12;	/* host-name */
701 			len = strlen(utsname()->nodename);
702 			*e++ = len;
703 			memcpy(e, utsname()->nodename, len);
704 			e += len;
705 		}
706 		if (*vendor_class_identifier) {
707 			pr_info("DHCP: sending class identifier \"%s\"\n",
708 				vendor_class_identifier);
709 			*e++ = 60;	/* Class-identifier */
710 			len = strlen(vendor_class_identifier);
711 			*e++ = len;
712 			memcpy(e, vendor_class_identifier, len);
713 			e += len;
714 		}
715 		len = strlen(dhcp_client_identifier + 1);
716 		/* the minimum length of identifier is 2, include 1 byte type,
717 		 * and can not be larger than the length of options
718 		 */
719 		if (len >= 1 && len < 312 - (e - options) - 1) {
720 			*e++ = 61;
721 			*e++ = len + 1;
722 			memcpy(e, dhcp_client_identifier, len + 1);
723 			e += len + 1;
724 		}
725 	}
726 
727 	*e++ = 255;	/* End of the list */
728 }
729 
730 #endif /* IPCONFIG_DHCP */
731 
732 static void __init ic_bootp_init_ext(u8 *e)
733 {
734 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
735 	e += 4;
736 	*e++ = 1;		/* Subnet mask request */
737 	*e++ = 4;
738 	e += 4;
739 	*e++ = 3;		/* Default gateway request */
740 	*e++ = 4;
741 	e += 4;
742 #if CONF_NAMESERVERS_MAX > 0
743 	*e++ = 6;		/* (DNS) name server request */
744 	*e++ = 4 * CONF_NAMESERVERS_MAX;
745 	e += 4 * CONF_NAMESERVERS_MAX;
746 #endif
747 	*e++ = 12;		/* Host name request */
748 	*e++ = 32;
749 	e += 32;
750 	*e++ = 40;		/* NIS Domain name request */
751 	*e++ = 32;
752 	e += 32;
753 	*e++ = 17;		/* Boot path */
754 	*e++ = 40;
755 	e += 40;
756 
757 	*e++ = 57;		/* set extension buffer size for reply */
758 	*e++ = 2;
759 	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
760 	*e++ = 150;
761 
762 	*e++ = 255;		/* End of the list */
763 }
764 
765 
766 /*
767  *  Initialize the DHCP/BOOTP mechanism.
768  */
769 static inline void __init ic_bootp_init(void)
770 {
771 	/* Re-initialise all name servers and NTP servers to NONE, in case any
772 	 * were set via the "ip=" or "nfsaddrs=" kernel command line parameters:
773 	 * any IP addresses specified there will already have been decoded but
774 	 * are no longer needed
775 	 */
776 	ic_nameservers_predef();
777 	ic_ntp_servers_predef();
778 
779 	dev_add_pack(&bootp_packet_type);
780 }
781 
782 
783 /*
784  *  DHCP/BOOTP cleanup.
785  */
786 static inline void __init ic_bootp_cleanup(void)
787 {
788 	dev_remove_pack(&bootp_packet_type);
789 }
790 
791 
792 /*
793  *  Send DHCP/BOOTP request to single interface.
794  */
795 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
796 {
797 	struct net_device *dev = d->dev;
798 	struct sk_buff *skb;
799 	struct bootp_pkt *b;
800 	struct iphdr *h;
801 	int hlen = LL_RESERVED_SPACE(dev);
802 	int tlen = dev->needed_tailroom;
803 
804 	/* Allocate packet */
805 	skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
806 			GFP_KERNEL);
807 	if (!skb)
808 		return;
809 	skb_reserve(skb, hlen);
810 	b = skb_put_zero(skb, sizeof(struct bootp_pkt));
811 
812 	/* Construct IP header */
813 	skb_reset_network_header(skb);
814 	h = ip_hdr(skb);
815 	h->version = 4;
816 	h->ihl = 5;
817 	h->tot_len = htons(sizeof(struct bootp_pkt));
818 	h->frag_off = htons(IP_DF);
819 	h->ttl = 64;
820 	h->protocol = IPPROTO_UDP;
821 	h->daddr = htonl(INADDR_BROADCAST);
822 	h->check = ip_fast_csum((unsigned char *) h, h->ihl);
823 
824 	/* Construct UDP header */
825 	b->udph.source = htons(68);
826 	b->udph.dest = htons(67);
827 	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
828 	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
829 
830 	/* Construct DHCP/BOOTP header */
831 	b->op = BOOTP_REQUEST;
832 	if (dev->type < 256) /* check for false types */
833 		b->htype = dev->type;
834 	else if (dev->type == ARPHRD_FDDI)
835 		b->htype = ARPHRD_ETHER;
836 	else {
837 		pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
838 			dev->name);
839 		b->htype = dev->type; /* can cause undefined behavior */
840 	}
841 
842 	/* server_ip and your_ip address are both already zero per RFC2131 */
843 	b->hlen = dev->addr_len;
844 	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
845 	b->secs = htons(jiffies_diff / HZ);
846 	b->xid = d->xid;
847 
848 	/* add DHCP options or BOOTP extensions */
849 #ifdef IPCONFIG_DHCP
850 	if (ic_proto_enabled & IC_USE_DHCP)
851 		ic_dhcp_init_options(b->exten, d);
852 	else
853 #endif
854 		ic_bootp_init_ext(b->exten);
855 
856 	/* Chain packet down the line... */
857 	skb->dev = dev;
858 	skb->protocol = htons(ETH_P_IP);
859 	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
860 			    dev->broadcast, dev->dev_addr, skb->len) < 0) {
861 		kfree_skb(skb);
862 		printk("E");
863 		return;
864 	}
865 
866 	if (dev_queue_xmit(skb) < 0)
867 		printk("E");
868 }
869 
870 
871 /*
872  *  Copy BOOTP-supplied string if not already set.
873  */
874 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
875 {
876 	if (!len)
877 		return 0;
878 	if (len > max-1)
879 		len = max-1;
880 	memcpy(dest, src, len);
881 	dest[len] = '\0';
882 	return 1;
883 }
884 
885 
886 /*
887  *  Process BOOTP extensions.
888  */
889 static void __init ic_do_bootp_ext(u8 *ext)
890 {
891 	u8 servers;
892 	int i;
893 	__be16 mtu;
894 
895 	u8 *c;
896 
897 	pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
898 	for (c=ext+2; c<ext+2+ext[1]; c++)
899 		pr_debug(" %02x", *c);
900 	pr_debug("\n");
901 
902 	switch (*ext++) {
903 	case 1:		/* Subnet mask */
904 		if (ic_netmask == NONE)
905 			memcpy(&ic_netmask, ext+1, 4);
906 		break;
907 	case 3:		/* Default gateway */
908 		if (ic_gateway == NONE)
909 			memcpy(&ic_gateway, ext+1, 4);
910 		break;
911 	case 6:		/* DNS server */
912 		servers= *ext/4;
913 		if (servers > CONF_NAMESERVERS_MAX)
914 			servers = CONF_NAMESERVERS_MAX;
915 		for (i = 0; i < servers; i++) {
916 			if (ic_nameservers[i] == NONE)
917 				memcpy(&ic_nameservers[i], ext+1+4*i, 4);
918 		}
919 		break;
920 	case 12:	/* Host name */
921 		ic_bootp_string(utsname()->nodename, ext+1, *ext,
922 				__NEW_UTS_LEN);
923 		ic_host_name_set = 1;
924 		break;
925 	case 15:	/* Domain name (DNS) */
926 		ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
927 		break;
928 	case 17:	/* Root path */
929 		if (!root_server_path[0])
930 			ic_bootp_string(root_server_path, ext+1, *ext,
931 					sizeof(root_server_path));
932 		break;
933 	case 26:	/* Interface MTU */
934 		memcpy(&mtu, ext+1, sizeof(mtu));
935 		ic_dev_mtu = ntohs(mtu);
936 		break;
937 	case 40:	/* NIS Domain name (_not_ DNS) */
938 		ic_bootp_string(utsname()->domainname, ext+1, *ext,
939 				__NEW_UTS_LEN);
940 		break;
941 	case 42:	/* NTP servers */
942 		servers = *ext / 4;
943 		if (servers > CONF_NTP_SERVERS_MAX)
944 			servers = CONF_NTP_SERVERS_MAX;
945 		for (i = 0; i < servers; i++) {
946 			if (ic_ntp_servers[i] == NONE)
947 				memcpy(&ic_ntp_servers[i], ext+1+4*i, 4);
948 		}
949 		break;
950 	}
951 }
952 
953 
954 /*
955  *  Receive BOOTP reply.
956  */
957 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
958 {
959 	struct bootp_pkt *b;
960 	struct iphdr *h;
961 	struct ic_device *d;
962 	int len, ext_len;
963 
964 	if (!net_eq(dev_net(dev), &init_net))
965 		goto drop;
966 
967 	/* Perform verifications before taking the lock.  */
968 	if (skb->pkt_type == PACKET_OTHERHOST)
969 		goto drop;
970 
971 	skb = skb_share_check(skb, GFP_ATOMIC);
972 	if (!skb)
973 		return NET_RX_DROP;
974 
975 	if (!pskb_may_pull(skb,
976 			   sizeof(struct iphdr) +
977 			   sizeof(struct udphdr)))
978 		goto drop;
979 
980 	b = (struct bootp_pkt *)skb_network_header(skb);
981 	h = &b->iph;
982 
983 	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
984 		goto drop;
985 
986 	/* Fragments are not supported */
987 	if (ip_is_fragment(h)) {
988 		net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
989 		goto drop;
990 	}
991 
992 	if (skb->len < ntohs(h->tot_len))
993 		goto drop;
994 
995 	if (ip_fast_csum((char *) h, h->ihl))
996 		goto drop;
997 
998 	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
999 		goto drop;
1000 
1001 	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
1002 		goto drop;
1003 
1004 	len = ntohs(b->udph.len) - sizeof(struct udphdr);
1005 	ext_len = len - (sizeof(*b) -
1006 			 sizeof(struct iphdr) -
1007 			 sizeof(struct udphdr) -
1008 			 sizeof(b->exten));
1009 	if (ext_len < 0)
1010 		goto drop;
1011 
1012 	/* Ok the front looks good, make sure we can get at the rest.  */
1013 	if (!pskb_may_pull(skb, skb->len))
1014 		goto drop;
1015 
1016 	b = (struct bootp_pkt *)skb_network_header(skb);
1017 	h = &b->iph;
1018 
1019 	/* One reply at a time, please. */
1020 	spin_lock(&ic_recv_lock);
1021 
1022 	/* If we already have a reply, just drop the packet */
1023 	if (ic_got_reply)
1024 		goto drop_unlock;
1025 
1026 	/* Find the ic_device that the packet arrived on */
1027 	d = ic_first_dev;
1028 	while (d && d->dev != dev)
1029 		d = d->next;
1030 	if (!d)
1031 		goto drop_unlock;  /* should never happen */
1032 
1033 	/* Is it a reply to our BOOTP request? */
1034 	if (b->op != BOOTP_REPLY ||
1035 	    b->xid != d->xid) {
1036 		net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1037 				    d->dev->name, b->op, b->xid);
1038 		goto drop_unlock;
1039 	}
1040 
1041 	/* Parse extensions */
1042 	if (ext_len >= 4 &&
1043 	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1044 		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1045 		u8 *ext;
1046 
1047 #ifdef IPCONFIG_DHCP
1048 		if (ic_proto_enabled & IC_USE_DHCP) {
1049 			__be32 server_id = NONE;
1050 			int mt = 0;
1051 
1052 			ext = &b->exten[4];
1053 			while (ext < end && *ext != 0xff) {
1054 				u8 *opt = ext++;
1055 				if (*opt == 0)	/* Padding */
1056 					continue;
1057 				ext += *ext + 1;
1058 				if (ext >= end)
1059 					break;
1060 				switch (*opt) {
1061 				case 53:	/* Message type */
1062 					if (opt[1])
1063 						mt = opt[2];
1064 					break;
1065 				case 54:	/* Server ID (IP address) */
1066 					if (opt[1] >= 4)
1067 						memcpy(&server_id, opt + 2, 4);
1068 					break;
1069 				}
1070 			}
1071 
1072 			pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1073 
1074 			switch (mt) {
1075 			case DHCPOFFER:
1076 				/* While in the process of accepting one offer,
1077 				 * ignore all others.
1078 				 */
1079 				if (ic_myaddr != NONE)
1080 					goto drop_unlock;
1081 
1082 				/* Let's accept that offer. */
1083 				ic_myaddr = b->your_ip;
1084 				ic_servaddr = server_id;
1085 				pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1086 					 &ic_myaddr, &b->iph.saddr);
1087 				/* The DHCP indicated server address takes
1088 				 * precedence over the bootp header one if
1089 				 * they are different.
1090 				 */
1091 				if ((server_id != NONE) &&
1092 				    (b->server_ip != server_id))
1093 					b->server_ip = ic_servaddr;
1094 				break;
1095 
1096 			case DHCPACK:
1097 				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1098 					goto drop_unlock;
1099 
1100 				/* Yeah! */
1101 				break;
1102 
1103 			default:
1104 				/* Urque.  Forget it*/
1105 				ic_myaddr = NONE;
1106 				ic_servaddr = NONE;
1107 				goto drop_unlock;
1108 			}
1109 
1110 			ic_dhcp_msgtype = mt;
1111 
1112 		}
1113 #endif /* IPCONFIG_DHCP */
1114 
1115 		ext = &b->exten[4];
1116 		while (ext < end && *ext != 0xff) {
1117 			u8 *opt = ext++;
1118 			if (*opt == 0)	/* Padding */
1119 				continue;
1120 			ext += *ext + 1;
1121 			if (ext < end)
1122 				ic_do_bootp_ext(opt);
1123 		}
1124 	}
1125 
1126 	/* We have a winner! */
1127 	ic_dev = d;
1128 	ic_myaddr = b->your_ip;
1129 	ic_servaddr = b->server_ip;
1130 	ic_addrservaddr = b->iph.saddr;
1131 	if (ic_gateway == NONE && b->relay_ip)
1132 		ic_gateway = b->relay_ip;
1133 	if (ic_nameservers[0] == NONE)
1134 		ic_nameservers[0] = ic_servaddr;
1135 	ic_got_reply = IC_BOOTP;
1136 
1137 drop_unlock:
1138 	/* Show's over.  Nothing to see here.  */
1139 	spin_unlock(&ic_recv_lock);
1140 
1141 drop:
1142 	/* Throw the packet out. */
1143 	kfree_skb(skb);
1144 
1145 	return 0;
1146 }
1147 
1148 
1149 #endif
1150 
1151 
1152 /*
1153  *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
1154  */
1155 
1156 #ifdef IPCONFIG_DYNAMIC
1157 
1158 static int __init ic_dynamic(void)
1159 {
1160 	int retries;
1161 	struct ic_device *d;
1162 	unsigned long start_jiffies, timeout, jiff;
1163 	int do_bootp = ic_proto_have_if & IC_BOOTP;
1164 	int do_rarp = ic_proto_have_if & IC_RARP;
1165 
1166 	/*
1167 	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1168 	 * This routine gets only called when some pieces of information
1169 	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1170 	 */
1171 	if (!ic_proto_enabled) {
1172 		pr_err("IP-Config: Incomplete network configuration information\n");
1173 		return -1;
1174 	}
1175 
1176 #ifdef IPCONFIG_BOOTP
1177 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1178 		pr_err("DHCP/BOOTP: No suitable device found\n");
1179 #endif
1180 #ifdef IPCONFIG_RARP
1181 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1182 		pr_err("RARP: No suitable device found\n");
1183 #endif
1184 
1185 	if (!ic_proto_have_if)
1186 		/* Error message already printed */
1187 		return -1;
1188 
1189 	/*
1190 	 * Setup protocols
1191 	 */
1192 #ifdef IPCONFIG_BOOTP
1193 	if (do_bootp)
1194 		ic_bootp_init();
1195 #endif
1196 #ifdef IPCONFIG_RARP
1197 	if (do_rarp)
1198 		ic_rarp_init();
1199 #endif
1200 
1201 	/*
1202 	 * Send requests and wait, until we get an answer. This loop
1203 	 * seems to be a terrible waste of CPU time, but actually there is
1204 	 * only one process running at all, so we don't need to use any
1205 	 * scheduler functions.
1206 	 * [Actually we could now, but the nothing else running note still
1207 	 *  applies.. - AC]
1208 	 */
1209 	pr_notice("Sending %s%s%s requests .",
1210 		  do_bootp
1211 		  ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1212 		  (do_bootp && do_rarp) ? " and " : "",
1213 		  do_rarp ? "RARP" : "");
1214 
1215 	start_jiffies = jiffies;
1216 	d = ic_first_dev;
1217 	retries = CONF_SEND_RETRIES;
1218 	get_random_bytes(&timeout, sizeof(timeout));
1219 	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1220 	for (;;) {
1221 #ifdef IPCONFIG_BOOTP
1222 		if (do_bootp && (d->able & IC_BOOTP))
1223 			ic_bootp_send_if(d, jiffies - start_jiffies);
1224 #endif
1225 #ifdef IPCONFIG_RARP
1226 		if (do_rarp && (d->able & IC_RARP))
1227 			ic_rarp_send_if(d);
1228 #endif
1229 
1230 		if (!d->next) {
1231 			jiff = jiffies + timeout;
1232 			while (time_before(jiffies, jiff) && !ic_got_reply)
1233 				schedule_timeout_uninterruptible(1);
1234 		}
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 			/* continue on device that got the reply */
1242 			d = ic_dev;
1243 			pr_cont(",");
1244 			continue;
1245 		}
1246 #endif /* IPCONFIG_DHCP */
1247 
1248 		if (ic_got_reply) {
1249 			pr_cont(" OK\n");
1250 			break;
1251 		}
1252 
1253 		if ((d = d->next))
1254 			continue;
1255 
1256 		if (! --retries) {
1257 			pr_cont(" timed out!\n");
1258 			break;
1259 		}
1260 
1261 		d = ic_first_dev;
1262 
1263 		timeout = timeout CONF_TIMEOUT_MULT;
1264 		if (timeout > CONF_TIMEOUT_MAX)
1265 			timeout = CONF_TIMEOUT_MAX;
1266 
1267 		pr_cont(".");
1268 	}
1269 
1270 #ifdef IPCONFIG_BOOTP
1271 	if (do_bootp)
1272 		ic_bootp_cleanup();
1273 #endif
1274 #ifdef IPCONFIG_RARP
1275 	if (do_rarp)
1276 		ic_rarp_cleanup();
1277 #endif
1278 
1279 	if (!ic_got_reply) {
1280 		ic_myaddr = NONE;
1281 		return -1;
1282 	}
1283 
1284 	pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1285 		((ic_got_reply & IC_RARP) ? "RARP"
1286 		: (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1287 		&ic_addrservaddr, &ic_myaddr);
1288 
1289 	return 0;
1290 }
1291 
1292 #endif /* IPCONFIG_DYNAMIC */
1293 
1294 #ifdef CONFIG_PROC_FS
1295 
1296 /* Name servers: */
1297 static int pnp_seq_show(struct seq_file *seq, void *v)
1298 {
1299 	int i;
1300 
1301 	if (ic_proto_used & IC_PROTO)
1302 		seq_printf(seq, "#PROTO: %s\n",
1303 			   (ic_proto_used & IC_RARP) ? "RARP"
1304 			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1305 	else
1306 		seq_puts(seq, "#MANUAL\n");
1307 
1308 	if (ic_domain[0])
1309 		seq_printf(seq,
1310 			   "domain %s\n", ic_domain);
1311 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1312 		if (ic_nameservers[i] != NONE)
1313 			seq_printf(seq, "nameserver %pI4\n",
1314 				   &ic_nameservers[i]);
1315 	}
1316 	if (ic_servaddr != NONE)
1317 		seq_printf(seq, "bootserver %pI4\n",
1318 			   &ic_servaddr);
1319 	return 0;
1320 }
1321 
1322 static int pnp_seq_open(struct inode *indoe, struct file *file)
1323 {
1324 	return single_open(file, pnp_seq_show, NULL);
1325 }
1326 
1327 static const struct file_operations pnp_seq_fops = {
1328 	.open		= pnp_seq_open,
1329 	.read		= seq_read,
1330 	.llseek		= seq_lseek,
1331 	.release	= single_release,
1332 };
1333 
1334 /* Create the /proc/net/ipconfig directory */
1335 static int __init ipconfig_proc_net_init(void)
1336 {
1337 	ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net);
1338 	if (!ipconfig_dir)
1339 		return -ENOMEM;
1340 
1341 	return 0;
1342 }
1343 
1344 /* Create a new file under /proc/net/ipconfig */
1345 static int ipconfig_proc_net_create(const char *name,
1346 				    const struct file_operations *fops)
1347 {
1348 	char *pname;
1349 	struct proc_dir_entry *p;
1350 
1351 	if (!ipconfig_dir)
1352 		return -ENOMEM;
1353 
1354 	pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name);
1355 	if (!pname)
1356 		return -ENOMEM;
1357 
1358 	p = proc_create(pname, 0444, init_net.proc_net, fops);
1359 	kfree(pname);
1360 	if (!p)
1361 		return -ENOMEM;
1362 
1363 	return 0;
1364 }
1365 
1366 /* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */
1367 static int ntp_servers_seq_show(struct seq_file *seq, void *v)
1368 {
1369 	int i;
1370 
1371 	for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1372 		if (ic_ntp_servers[i] != NONE)
1373 			seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]);
1374 	}
1375 	return 0;
1376 }
1377 
1378 static int ntp_servers_seq_open(struct inode *inode, struct file *file)
1379 {
1380 	return single_open(file, ntp_servers_seq_show, NULL);
1381 }
1382 
1383 static const struct file_operations ntp_servers_seq_fops = {
1384 	.open		= ntp_servers_seq_open,
1385 	.read		= seq_read,
1386 	.llseek		= seq_lseek,
1387 	.release	= single_release,
1388 };
1389 #endif /* CONFIG_PROC_FS */
1390 
1391 /*
1392  *  Extract IP address from the parameter string if needed. Note that we
1393  *  need to have root_server_addr set _before_ IPConfig gets called as it
1394  *  can override it.
1395  */
1396 __be32 __init root_nfs_parse_addr(char *name)
1397 {
1398 	__be32 addr;
1399 	int octets = 0;
1400 	char *cp, *cq;
1401 
1402 	cp = cq = name;
1403 	while (octets < 4) {
1404 		while (*cp >= '0' && *cp <= '9')
1405 			cp++;
1406 		if (cp == cq || cp - cq > 3)
1407 			break;
1408 		if (*cp == '.' || octets == 3)
1409 			octets++;
1410 		if (octets < 4)
1411 			cp++;
1412 		cq = cp;
1413 	}
1414 	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1415 		if (*cp == ':')
1416 			*cp++ = '\0';
1417 		addr = in_aton(name);
1418 		memmove(name, cp, strlen(cp) + 1);
1419 	} else
1420 		addr = NONE;
1421 
1422 	return addr;
1423 }
1424 
1425 #define DEVICE_WAIT_MAX		12 /* 12 seconds */
1426 
1427 static int __init wait_for_devices(void)
1428 {
1429 	int i;
1430 
1431 	for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1432 		struct net_device *dev;
1433 		int found = 0;
1434 
1435 		rtnl_lock();
1436 		for_each_netdev(&init_net, dev) {
1437 			if (ic_is_init_dev(dev)) {
1438 				found = 1;
1439 				break;
1440 			}
1441 		}
1442 		rtnl_unlock();
1443 		if (found)
1444 			return 0;
1445 		ssleep(1);
1446 	}
1447 	return -ENODEV;
1448 }
1449 
1450 /*
1451  *	IP Autoconfig dispatcher.
1452  */
1453 
1454 static int __init ip_auto_config(void)
1455 {
1456 	__be32 addr;
1457 #ifdef IPCONFIG_DYNAMIC
1458 	int retries = CONF_OPEN_RETRIES;
1459 #endif
1460 	int err;
1461 	unsigned int i;
1462 
1463 	/* Initialise all name servers and NTP servers to NONE (but only if the
1464 	 * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded,
1465 	 * otherwise we'll overwrite the IP addresses specified there)
1466 	 */
1467 	if (ic_set_manually == 0) {
1468 		ic_nameservers_predef();
1469 		ic_ntp_servers_predef();
1470 	}
1471 
1472 #ifdef CONFIG_PROC_FS
1473 	proc_create("pnp", 0444, init_net.proc_net, &pnp_seq_fops);
1474 
1475 	if (ipconfig_proc_net_init() == 0)
1476 		ipconfig_proc_net_create("ntp_servers", &ntp_servers_seq_fops);
1477 #endif /* CONFIG_PROC_FS */
1478 
1479 	if (!ic_enable)
1480 		return 0;
1481 
1482 	pr_debug("IP-Config: Entered.\n");
1483 #ifdef IPCONFIG_DYNAMIC
1484  try_try_again:
1485 #endif
1486 	/* Wait for devices to appear */
1487 	err = wait_for_devices();
1488 	if (err)
1489 		return err;
1490 
1491 	/* Setup all network devices */
1492 	err = ic_open_devs();
1493 	if (err)
1494 		return err;
1495 
1496 	/* Give drivers a chance to settle */
1497 	msleep(CONF_POST_OPEN);
1498 
1499 	/*
1500 	 * If the config information is insufficient (e.g., our IP address or
1501 	 * IP address of the boot server is missing or we have multiple network
1502 	 * interfaces and no default was set), use BOOTP or RARP to get the
1503 	 * missing values.
1504 	 */
1505 	if (ic_myaddr == NONE ||
1506 #ifdef CONFIG_ROOT_NFS
1507 	    (root_server_addr == NONE &&
1508 	     ic_servaddr == NONE &&
1509 	     ROOT_DEV == Root_NFS) ||
1510 #endif
1511 	    ic_first_dev->next) {
1512 #ifdef IPCONFIG_DYNAMIC
1513 		if (ic_dynamic() < 0) {
1514 			ic_close_devs();
1515 
1516 			/*
1517 			 * I don't know why, but sometimes the
1518 			 * eepro100 driver (at least) gets upset and
1519 			 * doesn't work the first time it's opened.
1520 			 * But then if you close it and reopen it, it
1521 			 * works just fine.  So we need to try that at
1522 			 * least once before giving up.
1523 			 *
1524 			 * Also, if the root will be NFS-mounted, we
1525 			 * have nowhere to go if DHCP fails.  So we
1526 			 * just have to keep trying forever.
1527 			 *
1528 			 * 				-- Chip
1529 			 */
1530 #ifdef CONFIG_ROOT_NFS
1531 			if (ROOT_DEV ==  Root_NFS) {
1532 				pr_err("IP-Config: Retrying forever (NFS root)...\n");
1533 				goto try_try_again;
1534 			}
1535 #endif
1536 
1537 			if (--retries) {
1538 				pr_err("IP-Config: Reopening network devices...\n");
1539 				goto try_try_again;
1540 			}
1541 
1542 			/* Oh, well.  At least we tried. */
1543 			pr_err("IP-Config: Auto-configuration of network failed\n");
1544 			return -1;
1545 		}
1546 #else /* !DYNAMIC */
1547 		pr_err("IP-Config: Incomplete network configuration information\n");
1548 		ic_close_devs();
1549 		return -1;
1550 #endif /* IPCONFIG_DYNAMIC */
1551 	} else {
1552 		/* Device selected manually or only one device -> use it */
1553 		ic_dev = ic_first_dev;
1554 	}
1555 
1556 	addr = root_nfs_parse_addr(root_server_path);
1557 	if (root_server_addr == NONE)
1558 		root_server_addr = addr;
1559 
1560 	/*
1561 	 * Use defaults wherever applicable.
1562 	 */
1563 	if (ic_defaults() < 0)
1564 		return -1;
1565 
1566 	/*
1567 	 * Record which protocol was actually used.
1568 	 */
1569 #ifdef IPCONFIG_DYNAMIC
1570 	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1571 #endif
1572 
1573 #ifndef IPCONFIG_SILENT
1574 	/*
1575 	 * Clue in the operator.
1576 	 */
1577 	pr_info("IP-Config: Complete:\n");
1578 
1579 	pr_info("     device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1580 		ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1581 		&ic_myaddr, &ic_netmask, &ic_gateway);
1582 	pr_info("     host=%s, domain=%s, nis-domain=%s\n",
1583 		utsname()->nodename, ic_domain, utsname()->domainname);
1584 	pr_info("     bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1585 		&ic_servaddr, &root_server_addr, root_server_path);
1586 	if (ic_dev_mtu)
1587 		pr_cont(", mtu=%d", ic_dev_mtu);
1588 	/* Name servers (if any): */
1589 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1590 		if (ic_nameservers[i] != NONE) {
1591 			if (i == 0)
1592 				pr_info("     nameserver%u=%pI4",
1593 					i, &ic_nameservers[i]);
1594 			else
1595 				pr_cont(", nameserver%u=%pI4",
1596 					i, &ic_nameservers[i]);
1597 		}
1598 		if (i + 1 == CONF_NAMESERVERS_MAX)
1599 			pr_cont("\n");
1600 	}
1601 	/* NTP servers (if any): */
1602 	for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1603 		if (ic_ntp_servers[i] != NONE) {
1604 			if (i == 0)
1605 				pr_info("     ntpserver%u=%pI4",
1606 					i, &ic_ntp_servers[i]);
1607 			else
1608 				pr_cont(", ntpserver%u=%pI4",
1609 					i, &ic_ntp_servers[i]);
1610 		}
1611 		if (i + 1 == CONF_NTP_SERVERS_MAX)
1612 			pr_cont("\n");
1613 	}
1614 #endif /* !SILENT */
1615 
1616 	/*
1617 	 * Close all network devices except the device we've
1618 	 * autoconfigured and set up routes.
1619 	 */
1620 	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1621 		err = -1;
1622 	else
1623 		err = 0;
1624 
1625 	ic_close_devs();
1626 
1627 	return err;
1628 }
1629 
1630 late_initcall(ip_auto_config);
1631 
1632 
1633 /*
1634  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1635  *  command line parameter.  See Documentation/filesystems/nfs/nfsroot.txt.
1636  */
1637 static int __init ic_proto_name(char *name)
1638 {
1639 	if (!strcmp(name, "on") || !strcmp(name, "any")) {
1640 		return 1;
1641 	}
1642 	if (!strcmp(name, "off") || !strcmp(name, "none")) {
1643 		return 0;
1644 	}
1645 #ifdef CONFIG_IP_PNP_DHCP
1646 	else if (!strncmp(name, "dhcp", 4)) {
1647 		char *client_id;
1648 
1649 		ic_proto_enabled &= ~IC_RARP;
1650 		client_id = strstr(name, "dhcp,");
1651 		if (client_id) {
1652 			char *v;
1653 
1654 			client_id = client_id + 5;
1655 			v = strchr(client_id, ',');
1656 			if (!v)
1657 				return 1;
1658 			*v = 0;
1659 			if (kstrtou8(client_id, 0, dhcp_client_identifier))
1660 				pr_debug("DHCP: Invalid client identifier type\n");
1661 			strncpy(dhcp_client_identifier + 1, v + 1, 251);
1662 			*v = ',';
1663 		}
1664 		return 1;
1665 	}
1666 #endif
1667 #ifdef CONFIG_IP_PNP_BOOTP
1668 	else if (!strcmp(name, "bootp")) {
1669 		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1670 		return 1;
1671 	}
1672 #endif
1673 #ifdef CONFIG_IP_PNP_RARP
1674 	else if (!strcmp(name, "rarp")) {
1675 		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1676 		return 1;
1677 	}
1678 #endif
1679 #ifdef IPCONFIG_DYNAMIC
1680 	else if (!strcmp(name, "both")) {
1681 		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1682 		return 1;
1683 	}
1684 #endif
1685 	return 0;
1686 }
1687 
1688 static int __init ip_auto_config_setup(char *addrs)
1689 {
1690 	char *cp, *ip, *dp;
1691 	int num = 0;
1692 
1693 	ic_set_manually = 1;
1694 	ic_enable = 1;
1695 
1696 	/*
1697 	 * If any dhcp, bootp etc options are set, leave autoconfig on
1698 	 * and skip the below static IP processing.
1699 	 */
1700 	if (ic_proto_name(addrs))
1701 		return 1;
1702 
1703 	/* If no static IP is given, turn off autoconfig and bail.  */
1704 	if (*addrs == 0 ||
1705 	    strcmp(addrs, "off") == 0 ||
1706 	    strcmp(addrs, "none") == 0) {
1707 		ic_enable = 0;
1708 		return 1;
1709 	}
1710 
1711 	/* Initialise all name servers and NTP servers to NONE */
1712 	ic_nameservers_predef();
1713 	ic_ntp_servers_predef();
1714 
1715 	/* Parse string for static IP assignment.  */
1716 	ip = addrs;
1717 	while (ip && *ip) {
1718 		if ((cp = strchr(ip, ':')))
1719 			*cp++ = '\0';
1720 		if (strlen(ip) > 0) {
1721 			pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1722 			switch (num) {
1723 			case 0:
1724 				if ((ic_myaddr = in_aton(ip)) == ANY)
1725 					ic_myaddr = NONE;
1726 				break;
1727 			case 1:
1728 				if ((ic_servaddr = in_aton(ip)) == ANY)
1729 					ic_servaddr = NONE;
1730 				break;
1731 			case 2:
1732 				if ((ic_gateway = in_aton(ip)) == ANY)
1733 					ic_gateway = NONE;
1734 				break;
1735 			case 3:
1736 				if ((ic_netmask = in_aton(ip)) == ANY)
1737 					ic_netmask = NONE;
1738 				break;
1739 			case 4:
1740 				if ((dp = strchr(ip, '.'))) {
1741 					*dp++ = '\0';
1742 					strlcpy(utsname()->domainname, dp,
1743 						sizeof(utsname()->domainname));
1744 				}
1745 				strlcpy(utsname()->nodename, ip,
1746 					sizeof(utsname()->nodename));
1747 				ic_host_name_set = 1;
1748 				break;
1749 			case 5:
1750 				strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1751 				break;
1752 			case 6:
1753 				if (ic_proto_name(ip) == 0 &&
1754 				    ic_myaddr == NONE) {
1755 					ic_enable = 0;
1756 				}
1757 				break;
1758 			case 7:
1759 				if (CONF_NAMESERVERS_MAX >= 1) {
1760 					ic_nameservers[0] = in_aton(ip);
1761 					if (ic_nameservers[0] == ANY)
1762 						ic_nameservers[0] = NONE;
1763 				}
1764 				break;
1765 			case 8:
1766 				if (CONF_NAMESERVERS_MAX >= 2) {
1767 					ic_nameservers[1] = in_aton(ip);
1768 					if (ic_nameservers[1] == ANY)
1769 						ic_nameservers[1] = NONE;
1770 				}
1771 				break;
1772 			case 9:
1773 				if (CONF_NTP_SERVERS_MAX >= 1) {
1774 					ic_ntp_servers[0] = in_aton(ip);
1775 					if (ic_ntp_servers[0] == ANY)
1776 						ic_ntp_servers[0] = NONE;
1777 				}
1778 				break;
1779 			}
1780 		}
1781 		ip = cp;
1782 		num++;
1783 	}
1784 
1785 	return 1;
1786 }
1787 __setup("ip=", ip_auto_config_setup);
1788 
1789 static int __init nfsaddrs_config_setup(char *addrs)
1790 {
1791 	return ip_auto_config_setup(addrs);
1792 }
1793 __setup("nfsaddrs=", nfsaddrs_config_setup);
1794 
1795 static int __init vendor_class_identifier_setup(char *addrs)
1796 {
1797 	if (strlcpy(vendor_class_identifier, addrs,
1798 		    sizeof(vendor_class_identifier))
1799 	    >= sizeof(vendor_class_identifier))
1800 		pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1801 			vendor_class_identifier);
1802 	return 1;
1803 }
1804 __setup("dhcpclass=", vendor_class_identifier_setup);
1805