1 /*
2  *  Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or
3  *  user-supplied information to configure own IP address and routes.
4  *
5  *  Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
6  *
7  *  Derived from network configuration code in fs/nfs/nfsroot.c,
8  *  originally Copyright (C) 1995, 1996 Gero Kuhlmann and me.
9  *
10  *  BOOTP rewritten to construct and analyse packets itself instead
11  *  of misusing the IP layer. num_bugs_causing_wrong_arp_replies--;
12  *					     -- MJ, December 1998
13  *
14  *  Fixed ip_auto_config_setup calling at startup in the new "Linker Magic"
15  *  initialization scheme.
16  *	- Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999
17  *
18  *  DHCP support added.  To users this looks like a whole separate
19  *  protocol, but we know it's just a bag on the side of BOOTP.
20  *		-- Chip Salzenberg <chip@valinux.com>, May 2000
21  *
22  *  Ported DHCP support from 2.2.16 to 2.4.0-test4
23  *              -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000
24  *
25  *  Merged changes from 2.2.19 into 2.4.3
26  *              -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001
27  *
28  *  Multiple Nameservers in /proc/net/pnp
29  *              --  Josef Siemes <jsiemes@web.de>, Aug 2002
30  */
31 
32 #include <linux/types.h>
33 #include <linux/string.h>
34 #include <linux/kernel.h>
35 #include <linux/jiffies.h>
36 #include <linux/random.h>
37 #include <linux/init.h>
38 #include <linux/utsname.h>
39 #include <linux/in.h>
40 #include <linux/if.h>
41 #include <linux/inet.h>
42 #include <linux/inetdevice.h>
43 #include <linux/netdevice.h>
44 #include <linux/if_arp.h>
45 #include <linux/skbuff.h>
46 #include <linux/ip.h>
47 #include <linux/socket.h>
48 #include <linux/route.h>
49 #include <linux/udp.h>
50 #include <linux/proc_fs.h>
51 #include <linux/seq_file.h>
52 #include <linux/major.h>
53 #include <linux/root_dev.h>
54 #include <linux/delay.h>
55 #include <linux/nfs_fs.h>
56 #include <linux/slab.h>
57 #include <net/net_namespace.h>
58 #include <net/arp.h>
59 #include <net/ip.h>
60 #include <net/ipconfig.h>
61 #include <net/route.h>
62 
63 #include <asm/uaccess.h>
64 #include <net/checksum.h>
65 #include <asm/processor.h>
66 
67 /* Define this to allow debugging output */
68 #undef IPCONFIG_DEBUG
69 
70 #ifdef IPCONFIG_DEBUG
71 #define DBG(x) printk x
72 #else
73 #define DBG(x) do { } while(0)
74 #endif
75 
76 #if defined(CONFIG_IP_PNP_DHCP)
77 #define IPCONFIG_DHCP
78 #endif
79 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
80 #define IPCONFIG_BOOTP
81 #endif
82 #if defined(CONFIG_IP_PNP_RARP)
83 #define IPCONFIG_RARP
84 #endif
85 #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
86 #define IPCONFIG_DYNAMIC
87 #endif
88 
89 /* Define the friendly delay before and after opening net devices */
90 #define CONF_PRE_OPEN		500	/* Before opening: 1/2 second */
91 #define CONF_POST_OPEN		1	/* After opening: 1 second */
92 
93 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
94 #define CONF_OPEN_RETRIES 	2	/* (Re)open devices twice */
95 #define CONF_SEND_RETRIES 	6	/* Send six requests per open */
96 #define CONF_INTER_TIMEOUT	(HZ/2)	/* Inter-device timeout: 1/2 second */
97 #define CONF_BASE_TIMEOUT	(HZ*2)	/* Initial timeout: 2 seconds */
98 #define CONF_TIMEOUT_RANDOM	(HZ)	/* Maximum amount of randomization */
99 #define CONF_TIMEOUT_MULT	*7/4	/* Rate of timeout growth */
100 #define CONF_TIMEOUT_MAX	(HZ*30)	/* Maximum allowed timeout */
101 #define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
102 					   - '3' from resolv.h */
103 
104 #define NONE cpu_to_be32(INADDR_NONE)
105 #define ANY cpu_to_be32(INADDR_ANY)
106 
107 /*
108  * Public IP configuration
109  */
110 
111 /* This is used by platforms which might be able to set the ipconfig
112  * variables using firmware environment vars.  If this is set, it will
113  * ignore such firmware variables.
114  */
115 int ic_set_manually __initdata = 0;		/* IPconfig parameters set manually */
116 
117 static int ic_enable __initdata = 0;		/* IP config enabled? */
118 
119 /* Protocol choice */
120 int ic_proto_enabled __initdata = 0
121 #ifdef IPCONFIG_BOOTP
122 			| IC_BOOTP
123 #endif
124 #ifdef CONFIG_IP_PNP_DHCP
125 			| IC_USE_DHCP
126 #endif
127 #ifdef IPCONFIG_RARP
128 			| IC_RARP
129 #endif
130 			;
131 
132 static int ic_host_name_set __initdata = 0;	/* Host name set by us? */
133 
134 __be32 ic_myaddr = NONE;		/* My IP address */
135 static __be32 ic_netmask = NONE;	/* Netmask for local subnet */
136 __be32 ic_gateway = NONE;	/* Gateway IP address */
137 
138 __be32 ic_servaddr = NONE;	/* Boot server IP address */
139 
140 __be32 root_server_addr = NONE;	/* Address of NFS server */
141 u8 root_server_path[256] = { 0, };	/* Path to mount as root */
142 
143 u32 ic_dev_xid;		/* Device under configuration */
144 
145 /* vendor class identifier */
146 static char vendor_class_identifier[253] __initdata;
147 
148 /* Persistent data: */
149 
150 static int ic_proto_used;			/* Protocol used, if any */
151 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
152 static u8 ic_domain[64];		/* DNS (not NIS) domain name */
153 
154 /*
155  * Private state.
156  */
157 
158 /* Name of user-selected boot device */
159 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
160 
161 /* Protocols supported by available interfaces */
162 static int ic_proto_have_if __initdata = 0;
163 
164 /* MTU for boot device */
165 static int ic_dev_mtu __initdata = 0;
166 
167 #ifdef IPCONFIG_DYNAMIC
168 static DEFINE_SPINLOCK(ic_recv_lock);
169 static volatile int ic_got_reply __initdata = 0;    /* Proto(s) that replied */
170 #endif
171 #ifdef IPCONFIG_DHCP
172 static int ic_dhcp_msgtype __initdata = 0;	/* DHCP msg type received */
173 #endif
174 
175 
176 /*
177  *	Network devices
178  */
179 
180 struct ic_device {
181 	struct ic_device *next;
182 	struct net_device *dev;
183 	unsigned short flags;
184 	short able;
185 	__be32 xid;
186 };
187 
188 static struct ic_device *ic_first_dev __initdata = NULL;/* List of open device */
189 static struct net_device *ic_dev __initdata = NULL;	/* Selected device */
190 
ic_device_match(struct net_device * dev)191 static bool __init ic_device_match(struct net_device *dev)
192 {
193 	if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
194 	    (!(dev->flags & IFF_LOOPBACK) &&
195 	     (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
196 	     strncmp(dev->name, "dummy", 5)))
197 		return true;
198 	return false;
199 }
200 
ic_open_devs(void)201 static int __init ic_open_devs(void)
202 {
203 	struct ic_device *d, **last;
204 	struct net_device *dev;
205 	unsigned short oflags;
206 
207 	last = &ic_first_dev;
208 	rtnl_lock();
209 
210 	/* bring loopback device up first */
211 	for_each_netdev(&init_net, dev) {
212 		if (!(dev->flags & IFF_LOOPBACK))
213 			continue;
214 		if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
215 			printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
216 	}
217 
218 	for_each_netdev(&init_net, dev) {
219 		if (dev->flags & IFF_LOOPBACK)
220 			continue;
221 		if (ic_device_match(dev)) {
222 			int able = 0;
223 			if (dev->mtu >= 364)
224 				able |= IC_BOOTP;
225 			else
226 				printk(KERN_WARNING "DHCP/BOOTP: Ignoring device %s, MTU %d too small", dev->name, dev->mtu);
227 			if (!(dev->flags & IFF_NOARP))
228 				able |= IC_RARP;
229 			able &= ic_proto_enabled;
230 			if (ic_proto_enabled && !able)
231 				continue;
232 			oflags = dev->flags;
233 			if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
234 				printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
235 				continue;
236 			}
237 			if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
238 				rtnl_unlock();
239 				return -ENOMEM;
240 			}
241 			d->dev = dev;
242 			*last = d;
243 			last = &d->next;
244 			d->flags = oflags;
245 			d->able = able;
246 			if (able & IC_BOOTP)
247 				get_random_bytes(&d->xid, sizeof(__be32));
248 			else
249 				d->xid = 0;
250 			ic_proto_have_if |= able;
251 			DBG(("IP-Config: %s UP (able=%d, xid=%08x)\n",
252 				dev->name, able, d->xid));
253 		}
254 	}
255 	rtnl_unlock();
256 
257 	*last = NULL;
258 
259 	if (!ic_first_dev) {
260 		if (user_dev_name[0])
261 			printk(KERN_ERR "IP-Config: Device `%s' not found.\n", user_dev_name);
262 		else
263 			printk(KERN_ERR "IP-Config: No network devices available.\n");
264 		return -ENODEV;
265 	}
266 	return 0;
267 }
268 
ic_close_devs(void)269 static void __init ic_close_devs(void)
270 {
271 	struct ic_device *d, *next;
272 	struct net_device *dev;
273 
274 	rtnl_lock();
275 	next = ic_first_dev;
276 	while ((d = next)) {
277 		next = d->next;
278 		dev = d->dev;
279 		if (dev != ic_dev) {
280 			DBG(("IP-Config: Downing %s\n", dev->name));
281 			dev_change_flags(dev, d->flags);
282 		}
283 		kfree(d);
284 	}
285 	rtnl_unlock();
286 }
287 
288 /*
289  *	Interface to various network functions.
290  */
291 
292 static inline void
set_sockaddr(struct sockaddr_in * sin,__be32 addr,__be16 port)293 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
294 {
295 	sin->sin_family = AF_INET;
296 	sin->sin_addr.s_addr = addr;
297 	sin->sin_port = port;
298 }
299 
ic_devinet_ioctl(unsigned int cmd,struct ifreq * arg)300 static int __init ic_devinet_ioctl(unsigned int cmd, struct ifreq *arg)
301 {
302 	int res;
303 
304 	mm_segment_t oldfs = get_fs();
305 	set_fs(get_ds());
306 	res = devinet_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
307 	set_fs(oldfs);
308 	return res;
309 }
310 
ic_dev_ioctl(unsigned int cmd,struct ifreq * arg)311 static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
312 {
313 	int res;
314 
315 	mm_segment_t oldfs = get_fs();
316 	set_fs(get_ds());
317 	res = dev_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
318 	set_fs(oldfs);
319 	return res;
320 }
321 
ic_route_ioctl(unsigned int cmd,struct rtentry * arg)322 static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg)
323 {
324 	int res;
325 
326 	mm_segment_t oldfs = get_fs();
327 	set_fs(get_ds());
328 	res = ip_rt_ioctl(&init_net, cmd, (void __user *) arg);
329 	set_fs(oldfs);
330 	return res;
331 }
332 
333 /*
334  *	Set up interface addresses and routes.
335  */
336 
ic_setup_if(void)337 static int __init ic_setup_if(void)
338 {
339 	struct ifreq ir;
340 	struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
341 	int err;
342 
343 	memset(&ir, 0, sizeof(ir));
344 	strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->name);
345 	set_sockaddr(sin, ic_myaddr, 0);
346 	if ((err = ic_devinet_ioctl(SIOCSIFADDR, &ir)) < 0) {
347 		printk(KERN_ERR "IP-Config: Unable to set interface address (%d).\n", err);
348 		return -1;
349 	}
350 	set_sockaddr(sin, ic_netmask, 0);
351 	if ((err = ic_devinet_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
352 		printk(KERN_ERR "IP-Config: Unable to set interface netmask (%d).\n", err);
353 		return -1;
354 	}
355 	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
356 	if ((err = ic_devinet_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
357 		printk(KERN_ERR "IP-Config: Unable to set interface broadcast address (%d).\n", err);
358 		return -1;
359 	}
360 	/* Handle the case where we need non-standard MTU on the boot link (a network
361 	 * using jumbo frames, for instance).  If we can't set the mtu, don't error
362 	 * out, we'll try to muddle along.
363 	 */
364 	if (ic_dev_mtu != 0) {
365 		strcpy(ir.ifr_name, ic_dev->name);
366 		ir.ifr_mtu = ic_dev_mtu;
367 		if ((err = ic_dev_ioctl(SIOCSIFMTU, &ir)) < 0)
368 			printk(KERN_ERR "IP-Config: Unable to set interface mtu to %d (%d).\n",
369 			                 ic_dev_mtu, err);
370 	}
371 	return 0;
372 }
373 
ic_setup_routes(void)374 static int __init ic_setup_routes(void)
375 {
376 	/* No need to setup device routes, only the default route... */
377 
378 	if (ic_gateway != NONE) {
379 		struct rtentry rm;
380 		int err;
381 
382 		memset(&rm, 0, sizeof(rm));
383 		if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
384 			printk(KERN_ERR "IP-Config: Gateway not on directly connected network.\n");
385 			return -1;
386 		}
387 		set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
388 		set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
389 		set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
390 		rm.rt_flags = RTF_UP | RTF_GATEWAY;
391 		if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) {
392 			printk(KERN_ERR "IP-Config: Cannot add default route (%d).\n", err);
393 			return -1;
394 		}
395 	}
396 
397 	return 0;
398 }
399 
400 /*
401  *	Fill in default values for all missing parameters.
402  */
403 
ic_defaults(void)404 static int __init ic_defaults(void)
405 {
406 	/*
407 	 *	At this point we have no userspace running so need not
408 	 *	claim locks on system_utsname
409 	 */
410 
411 	if (!ic_host_name_set)
412 		sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
413 
414 	if (root_server_addr == NONE)
415 		root_server_addr = ic_servaddr;
416 
417 	if (ic_netmask == NONE) {
418 		if (IN_CLASSA(ntohl(ic_myaddr)))
419 			ic_netmask = htonl(IN_CLASSA_NET);
420 		else if (IN_CLASSB(ntohl(ic_myaddr)))
421 			ic_netmask = htonl(IN_CLASSB_NET);
422 		else if (IN_CLASSC(ntohl(ic_myaddr)))
423 			ic_netmask = htonl(IN_CLASSC_NET);
424 		else {
425 			printk(KERN_ERR "IP-Config: Unable to guess netmask for address %pI4\n",
426 				&ic_myaddr);
427 			return -1;
428 		}
429 		printk("IP-Config: Guessing netmask %pI4\n", &ic_netmask);
430 	}
431 
432 	return 0;
433 }
434 
435 /*
436  *	RARP support.
437  */
438 
439 #ifdef IPCONFIG_RARP
440 
441 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
442 
443 static struct packet_type rarp_packet_type __initdata = {
444 	.type =	cpu_to_be16(ETH_P_RARP),
445 	.func =	ic_rarp_recv,
446 };
447 
ic_rarp_init(void)448 static inline void __init ic_rarp_init(void)
449 {
450 	dev_add_pack(&rarp_packet_type);
451 }
452 
ic_rarp_cleanup(void)453 static inline void __init ic_rarp_cleanup(void)
454 {
455 	dev_remove_pack(&rarp_packet_type);
456 }
457 
458 /*
459  *  Process received RARP packet.
460  */
461 static int __init
ic_rarp_recv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)462 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
463 {
464 	struct arphdr *rarp;
465 	unsigned char *rarp_ptr;
466 	__be32 sip, tip;
467 	unsigned char *sha, *tha;		/* s for "source", t for "target" */
468 	struct ic_device *d;
469 
470 	if (!net_eq(dev_net(dev), &init_net))
471 		goto drop;
472 
473 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
474 		return NET_RX_DROP;
475 
476 	if (!pskb_may_pull(skb, sizeof(struct arphdr)))
477 		goto drop;
478 
479 	/* Basic sanity checks can be done without the lock.  */
480 	rarp = (struct arphdr *)skb_transport_header(skb);
481 
482 	/* If this test doesn't pass, it's not IP, or we should
483 	 * ignore it anyway.
484 	 */
485 	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
486 		goto drop;
487 
488 	/* If it's not a RARP reply, delete it. */
489 	if (rarp->ar_op != htons(ARPOP_RREPLY))
490 		goto drop;
491 
492 	/* If it's not Ethernet, delete it. */
493 	if (rarp->ar_pro != htons(ETH_P_IP))
494 		goto drop;
495 
496 	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
497 		goto drop;
498 
499 	/* OK, it is all there and looks valid, process... */
500 	rarp = (struct arphdr *)skb_transport_header(skb);
501 	rarp_ptr = (unsigned char *) (rarp + 1);
502 
503 	/* One reply at a time, please. */
504 	spin_lock(&ic_recv_lock);
505 
506 	/* If we already have a reply, just drop the packet */
507 	if (ic_got_reply)
508 		goto drop_unlock;
509 
510 	/* Find the ic_device that the packet arrived on */
511 	d = ic_first_dev;
512 	while (d && d->dev != dev)
513 		d = d->next;
514 	if (!d)
515 		goto drop_unlock;	/* should never happen */
516 
517 	/* Extract variable-width fields */
518 	sha = rarp_ptr;
519 	rarp_ptr += dev->addr_len;
520 	memcpy(&sip, rarp_ptr, 4);
521 	rarp_ptr += 4;
522 	tha = rarp_ptr;
523 	rarp_ptr += dev->addr_len;
524 	memcpy(&tip, rarp_ptr, 4);
525 
526 	/* Discard packets which are not meant for us. */
527 	if (memcmp(tha, dev->dev_addr, dev->addr_len))
528 		goto drop_unlock;
529 
530 	/* Discard packets which are not from specified server. */
531 	if (ic_servaddr != NONE && ic_servaddr != sip)
532 		goto drop_unlock;
533 
534 	/* We have a winner! */
535 	ic_dev = dev;
536 	if (ic_myaddr == NONE)
537 		ic_myaddr = tip;
538 	ic_servaddr = sip;
539 	ic_got_reply = IC_RARP;
540 
541 drop_unlock:
542 	/* Show's over.  Nothing to see here.  */
543 	spin_unlock(&ic_recv_lock);
544 
545 drop:
546 	/* Throw the packet out. */
547 	kfree_skb(skb);
548 	return 0;
549 }
550 
551 
552 /*
553  *  Send RARP request packet over a single interface.
554  */
ic_rarp_send_if(struct ic_device * d)555 static void __init ic_rarp_send_if(struct ic_device *d)
556 {
557 	struct net_device *dev = d->dev;
558 	arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
559 		 dev->dev_addr, dev->dev_addr);
560 }
561 #endif
562 
563 /*
564  *	DHCP/BOOTP support.
565  */
566 
567 #ifdef IPCONFIG_BOOTP
568 
569 struct bootp_pkt {		/* BOOTP packet format */
570 	struct iphdr iph;	/* IP header */
571 	struct udphdr udph;	/* UDP header */
572 	u8 op;			/* 1=request, 2=reply */
573 	u8 htype;		/* HW address type */
574 	u8 hlen;		/* HW address length */
575 	u8 hops;		/* Used only by gateways */
576 	__be32 xid;		/* Transaction ID */
577 	__be16 secs;		/* Seconds since we started */
578 	__be16 flags;		/* Just what it says */
579 	__be32 client_ip;		/* Client's IP address if known */
580 	__be32 your_ip;		/* Assigned IP address */
581 	__be32 server_ip;		/* (Next, e.g. NFS) Server's IP address */
582 	__be32 relay_ip;		/* IP address of BOOTP relay */
583 	u8 hw_addr[16];		/* Client's HW address */
584 	u8 serv_name[64];	/* Server host name */
585 	u8 boot_file[128];	/* Name of boot file */
586 	u8 exten[312];		/* DHCP options / BOOTP vendor extensions */
587 };
588 
589 /* packet ops */
590 #define BOOTP_REQUEST	1
591 #define BOOTP_REPLY	2
592 
593 /* DHCP message types */
594 #define DHCPDISCOVER	1
595 #define DHCPOFFER	2
596 #define DHCPREQUEST	3
597 #define DHCPDECLINE	4
598 #define DHCPACK		5
599 #define DHCPNAK		6
600 #define DHCPRELEASE	7
601 #define DHCPINFORM	8
602 
603 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
604 
605 static struct packet_type bootp_packet_type __initdata = {
606 	.type =	cpu_to_be16(ETH_P_IP),
607 	.func =	ic_bootp_recv,
608 };
609 
610 
611 /*
612  *  Initialize DHCP/BOOTP extension fields in the request.
613  */
614 
615 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
616 
617 #ifdef IPCONFIG_DHCP
618 
619 static void __init
ic_dhcp_init_options(u8 * options)620 ic_dhcp_init_options(u8 *options)
621 {
622 	u8 mt = ((ic_servaddr == NONE)
623 		 ? DHCPDISCOVER : DHCPREQUEST);
624 	u8 *e = options;
625 	int len;
626 
627 #ifdef IPCONFIG_DEBUG
628 	printk("DHCP: Sending message type %d\n", mt);
629 #endif
630 
631 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
632 	e += 4;
633 
634 	*e++ = 53;		/* DHCP message type */
635 	*e++ = 1;
636 	*e++ = mt;
637 
638 	if (mt == DHCPREQUEST) {
639 		*e++ = 54;	/* Server ID (IP address) */
640 		*e++ = 4;
641 		memcpy(e, &ic_servaddr, 4);
642 		e += 4;
643 
644 		*e++ = 50;	/* Requested IP address */
645 		*e++ = 4;
646 		memcpy(e, &ic_myaddr, 4);
647 		e += 4;
648 	}
649 
650 	/* always? */
651 	{
652 		static const u8 ic_req_params[] = {
653 			1,	/* Subnet mask */
654 			3,	/* Default gateway */
655 			6,	/* DNS server */
656 			12,	/* Host name */
657 			15,	/* Domain name */
658 			17,	/* Boot path */
659 			26,	/* MTU */
660 			40,	/* NIS domain name */
661 		};
662 
663 		*e++ = 55;	/* Parameter request list */
664 		*e++ = sizeof(ic_req_params);
665 		memcpy(e, ic_req_params, sizeof(ic_req_params));
666 		e += sizeof(ic_req_params);
667 
668 		if (ic_host_name_set) {
669 			*e++ = 12;	/* host-name */
670 			len = strlen(utsname()->nodename);
671 			*e++ = len;
672 			memcpy(e, utsname()->nodename, len);
673 			e += len;
674 		}
675 		if (*vendor_class_identifier) {
676 			printk(KERN_INFO "DHCP: sending class identifier \"%s\"\n",
677 			       vendor_class_identifier);
678 			*e++ = 60;	/* Class-identifier */
679 			len = strlen(vendor_class_identifier);
680 			*e++ = len;
681 			memcpy(e, vendor_class_identifier, len);
682 			e += len;
683 		}
684 	}
685 
686 	*e++ = 255;	/* End of the list */
687 }
688 
689 #endif /* IPCONFIG_DHCP */
690 
ic_bootp_init_ext(u8 * e)691 static void __init ic_bootp_init_ext(u8 *e)
692 {
693 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
694 	e += 4;
695 	*e++ = 1;		/* Subnet mask request */
696 	*e++ = 4;
697 	e += 4;
698 	*e++ = 3;		/* Default gateway request */
699 	*e++ = 4;
700 	e += 4;
701 	*e++ = 5;		/* Name server request */
702 	*e++ = 8;
703 	e += 8;
704 	*e++ = 12;		/* Host name request */
705 	*e++ = 32;
706 	e += 32;
707 	*e++ = 40;		/* NIS Domain name request */
708 	*e++ = 32;
709 	e += 32;
710 	*e++ = 17;		/* Boot path */
711 	*e++ = 40;
712 	e += 40;
713 
714 	*e++ = 57;		/* set extension buffer size for reply */
715 	*e++ = 2;
716 	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
717 	*e++ = 150;
718 
719 	*e++ = 255;		/* End of the list */
720 }
721 
722 
723 /*
724  *  Initialize the DHCP/BOOTP mechanism.
725  */
ic_bootp_init(void)726 static inline void __init ic_bootp_init(void)
727 {
728 	int i;
729 
730 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
731 		ic_nameservers[i] = NONE;
732 
733 	dev_add_pack(&bootp_packet_type);
734 }
735 
736 
737 /*
738  *  DHCP/BOOTP cleanup.
739  */
ic_bootp_cleanup(void)740 static inline void __init ic_bootp_cleanup(void)
741 {
742 	dev_remove_pack(&bootp_packet_type);
743 }
744 
745 
746 /*
747  *  Send DHCP/BOOTP request to single interface.
748  */
ic_bootp_send_if(struct ic_device * d,unsigned long jiffies_diff)749 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
750 {
751 	struct net_device *dev = d->dev;
752 	struct sk_buff *skb;
753 	struct bootp_pkt *b;
754 	struct iphdr *h;
755 
756 	/* Allocate packet */
757 	skb = alloc_skb(sizeof(struct bootp_pkt) + LL_ALLOCATED_SPACE(dev) + 15,
758 			GFP_KERNEL);
759 	if (!skb)
760 		return;
761 	skb_reserve(skb, LL_RESERVED_SPACE(dev));
762 	b = (struct bootp_pkt *) skb_put(skb, sizeof(struct bootp_pkt));
763 	memset(b, 0, sizeof(struct bootp_pkt));
764 
765 	/* Construct IP header */
766 	skb_reset_network_header(skb);
767 	h = ip_hdr(skb);
768 	h->version = 4;
769 	h->ihl = 5;
770 	h->tot_len = htons(sizeof(struct bootp_pkt));
771 	h->frag_off = htons(IP_DF);
772 	h->ttl = 64;
773 	h->protocol = IPPROTO_UDP;
774 	h->daddr = htonl(INADDR_BROADCAST);
775 	h->check = ip_fast_csum((unsigned char *) h, h->ihl);
776 
777 	/* Construct UDP header */
778 	b->udph.source = htons(68);
779 	b->udph.dest = htons(67);
780 	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
781 	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
782 
783 	/* Construct DHCP/BOOTP header */
784 	b->op = BOOTP_REQUEST;
785 	if (dev->type < 256) /* check for false types */
786 		b->htype = dev->type;
787 	else if (dev->type == ARPHRD_IEEE802_TR) /* fix for token ring */
788 		b->htype = ARPHRD_IEEE802;
789 	else if (dev->type == ARPHRD_FDDI)
790 		b->htype = ARPHRD_ETHER;
791 	else {
792 		printk("Unknown ARP type 0x%04x for device %s\n", dev->type, dev->name);
793 		b->htype = dev->type; /* can cause undefined behavior */
794 	}
795 
796 	/* server_ip and your_ip address are both already zero per RFC2131 */
797 	b->hlen = dev->addr_len;
798 	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
799 	b->secs = htons(jiffies_diff / HZ);
800 	b->xid = d->xid;
801 
802 	/* add DHCP options or BOOTP extensions */
803 #ifdef IPCONFIG_DHCP
804 	if (ic_proto_enabled & IC_USE_DHCP)
805 		ic_dhcp_init_options(b->exten);
806 	else
807 #endif
808 		ic_bootp_init_ext(b->exten);
809 
810 	/* Chain packet down the line... */
811 	skb->dev = dev;
812 	skb->protocol = htons(ETH_P_IP);
813 	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
814 			    dev->broadcast, dev->dev_addr, skb->len) < 0 ||
815 	    dev_queue_xmit(skb) < 0)
816 		printk("E");
817 }
818 
819 
820 /*
821  *  Copy BOOTP-supplied string if not already set.
822  */
ic_bootp_string(char * dest,char * src,int len,int max)823 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
824 {
825 	if (!len)
826 		return 0;
827 	if (len > max-1)
828 		len = max-1;
829 	memcpy(dest, src, len);
830 	dest[len] = '\0';
831 	return 1;
832 }
833 
834 
835 /*
836  *  Process BOOTP extensions.
837  */
ic_do_bootp_ext(u8 * ext)838 static void __init ic_do_bootp_ext(u8 *ext)
839 {
840        u8 servers;
841        int i;
842 	u16 mtu;
843 
844 #ifdef IPCONFIG_DEBUG
845 	u8 *c;
846 
847 	printk("DHCP/BOOTP: Got extension %d:",*ext);
848 	for (c=ext+2; c<ext+2+ext[1]; c++)
849 		printk(" %02x", *c);
850 	printk("\n");
851 #endif
852 
853 	switch (*ext++) {
854 		case 1:		/* Subnet mask */
855 			if (ic_netmask == NONE)
856 				memcpy(&ic_netmask, ext+1, 4);
857 			break;
858 		case 3:		/* Default gateway */
859 			if (ic_gateway == NONE)
860 				memcpy(&ic_gateway, ext+1, 4);
861 			break;
862 		case 6:		/* DNS server */
863 			servers= *ext/4;
864 			if (servers > CONF_NAMESERVERS_MAX)
865 				servers = CONF_NAMESERVERS_MAX;
866 			for (i = 0; i < servers; i++) {
867 				if (ic_nameservers[i] == NONE)
868 					memcpy(&ic_nameservers[i], ext+1+4*i, 4);
869 			}
870 			break;
871 		case 12:	/* Host name */
872 			ic_bootp_string(utsname()->nodename, ext+1, *ext, __NEW_UTS_LEN);
873 			ic_host_name_set = 1;
874 			break;
875 		case 15:	/* Domain name (DNS) */
876 			ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
877 			break;
878 		case 17:	/* Root path */
879 			if (!root_server_path[0])
880 				ic_bootp_string(root_server_path, ext+1, *ext, sizeof(root_server_path));
881 			break;
882 		case 26:	/* Interface MTU */
883 			memcpy(&mtu, ext+1, sizeof(mtu));
884 			ic_dev_mtu = ntohs(mtu);
885 			break;
886 		case 40:	/* NIS Domain name (_not_ DNS) */
887 			ic_bootp_string(utsname()->domainname, ext+1, *ext, __NEW_UTS_LEN);
888 			break;
889 	}
890 }
891 
892 
893 /*
894  *  Receive BOOTP reply.
895  */
ic_bootp_recv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)896 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
897 {
898 	struct bootp_pkt *b;
899 	struct iphdr *h;
900 	struct ic_device *d;
901 	int len, ext_len;
902 
903 	if (!net_eq(dev_net(dev), &init_net))
904 		goto drop;
905 
906 	/* Perform verifications before taking the lock.  */
907 	if (skb->pkt_type == PACKET_OTHERHOST)
908 		goto drop;
909 
910 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
911 		return NET_RX_DROP;
912 
913 	if (!pskb_may_pull(skb,
914 			   sizeof(struct iphdr) +
915 			   sizeof(struct udphdr)))
916 		goto drop;
917 
918 	b = (struct bootp_pkt *)skb_network_header(skb);
919 	h = &b->iph;
920 
921 	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
922 		goto drop;
923 
924 	/* Fragments are not supported */
925 	if (h->frag_off & htons(IP_OFFSET | IP_MF)) {
926 		if (net_ratelimit())
927 			printk(KERN_ERR "DHCP/BOOTP: Ignoring fragmented "
928 			       "reply.\n");
929 		goto drop;
930 	}
931 
932 	if (skb->len < ntohs(h->tot_len))
933 		goto drop;
934 
935 	if (ip_fast_csum((char *) h, h->ihl))
936 		goto drop;
937 
938 	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
939 		goto drop;
940 
941 	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
942 		goto drop;
943 
944 	len = ntohs(b->udph.len) - sizeof(struct udphdr);
945 	ext_len = len - (sizeof(*b) -
946 			 sizeof(struct iphdr) -
947 			 sizeof(struct udphdr) -
948 			 sizeof(b->exten));
949 	if (ext_len < 0)
950 		goto drop;
951 
952 	/* Ok the front looks good, make sure we can get at the rest.  */
953 	if (!pskb_may_pull(skb, skb->len))
954 		goto drop;
955 
956 	b = (struct bootp_pkt *)skb_network_header(skb);
957 	h = &b->iph;
958 
959 	/* One reply at a time, please. */
960 	spin_lock(&ic_recv_lock);
961 
962 	/* If we already have a reply, just drop the packet */
963 	if (ic_got_reply)
964 		goto drop_unlock;
965 
966 	/* Find the ic_device that the packet arrived on */
967 	d = ic_first_dev;
968 	while (d && d->dev != dev)
969 		d = d->next;
970 	if (!d)
971 		goto drop_unlock;  /* should never happen */
972 
973 	/* Is it a reply to our BOOTP request? */
974 	if (b->op != BOOTP_REPLY ||
975 	    b->xid != d->xid) {
976 		if (net_ratelimit())
977 			printk(KERN_ERR "DHCP/BOOTP: Reply not for us, "
978 			       "op[%x] xid[%x]\n",
979 			       b->op, b->xid);
980 		goto drop_unlock;
981 	}
982 
983 	/* Is it a reply for the device we are configuring? */
984 	if (b->xid != ic_dev_xid) {
985 		if (net_ratelimit())
986 			printk(KERN_ERR "DHCP/BOOTP: Ignoring delayed packet\n");
987 		goto drop_unlock;
988 	}
989 
990 	/* Parse extensions */
991 	if (ext_len >= 4 &&
992 	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
993 		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
994 		u8 *ext;
995 
996 #ifdef IPCONFIG_DHCP
997 		if (ic_proto_enabled & IC_USE_DHCP) {
998 			__be32 server_id = NONE;
999 			int mt = 0;
1000 
1001 			ext = &b->exten[4];
1002 			while (ext < end && *ext != 0xff) {
1003 				u8 *opt = ext++;
1004 				if (*opt == 0)	/* Padding */
1005 					continue;
1006 				ext += *ext + 1;
1007 				if (ext >= end)
1008 					break;
1009 				switch (*opt) {
1010 				case 53:	/* Message type */
1011 					if (opt[1])
1012 						mt = opt[2];
1013 					break;
1014 				case 54:	/* Server ID (IP address) */
1015 					if (opt[1] >= 4)
1016 						memcpy(&server_id, opt + 2, 4);
1017 					break;
1018 				}
1019 			}
1020 
1021 #ifdef IPCONFIG_DEBUG
1022 			printk("DHCP: Got message type %d\n", mt);
1023 #endif
1024 
1025 			switch (mt) {
1026 			case DHCPOFFER:
1027 				/* While in the process of accepting one offer,
1028 				 * ignore all others.
1029 				 */
1030 				if (ic_myaddr != NONE)
1031 					goto drop_unlock;
1032 
1033 				/* Let's accept that offer. */
1034 				ic_myaddr = b->your_ip;
1035 				ic_servaddr = server_id;
1036 #ifdef IPCONFIG_DEBUG
1037 				printk("DHCP: Offered address %pI4 by server %pI4\n",
1038 				       &ic_myaddr, &ic_servaddr);
1039 #endif
1040 				/* The DHCP indicated server address takes
1041 				 * precedence over the bootp header one if
1042 				 * they are different.
1043 				 */
1044 				if ((server_id != NONE) &&
1045 				    (b->server_ip != server_id))
1046 					b->server_ip = ic_servaddr;
1047 				break;
1048 
1049 			case DHCPACK:
1050 				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1051 					goto drop_unlock;
1052 
1053 				/* Yeah! */
1054 				break;
1055 
1056 			default:
1057 				/* Urque.  Forget it*/
1058 				ic_myaddr = NONE;
1059 				ic_servaddr = NONE;
1060 				goto drop_unlock;
1061 			}
1062 
1063 			ic_dhcp_msgtype = mt;
1064 
1065 		}
1066 #endif /* IPCONFIG_DHCP */
1067 
1068 		ext = &b->exten[4];
1069 		while (ext < end && *ext != 0xff) {
1070 			u8 *opt = ext++;
1071 			if (*opt == 0)	/* Padding */
1072 				continue;
1073 			ext += *ext + 1;
1074 			if (ext < end)
1075 				ic_do_bootp_ext(opt);
1076 		}
1077 	}
1078 
1079 	/* We have a winner! */
1080 	ic_dev = dev;
1081 	ic_myaddr = b->your_ip;
1082 	ic_servaddr = b->server_ip;
1083 	if (ic_gateway == NONE && b->relay_ip)
1084 		ic_gateway = b->relay_ip;
1085 	if (ic_nameservers[0] == NONE)
1086 		ic_nameservers[0] = ic_servaddr;
1087 	ic_got_reply = IC_BOOTP;
1088 
1089 drop_unlock:
1090 	/* Show's over.  Nothing to see here.  */
1091 	spin_unlock(&ic_recv_lock);
1092 
1093 drop:
1094 	/* Throw the packet out. */
1095 	kfree_skb(skb);
1096 
1097 	return 0;
1098 }
1099 
1100 
1101 #endif
1102 
1103 
1104 /*
1105  *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
1106  */
1107 
1108 #ifdef IPCONFIG_DYNAMIC
1109 
ic_dynamic(void)1110 static int __init ic_dynamic(void)
1111 {
1112 	int retries;
1113 	struct ic_device *d;
1114 	unsigned long start_jiffies, timeout, jiff;
1115 	int do_bootp = ic_proto_have_if & IC_BOOTP;
1116 	int do_rarp = ic_proto_have_if & IC_RARP;
1117 
1118 	/*
1119 	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1120 	 * This routine gets only called when some pieces of information
1121 	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1122 	 */
1123 	if (!ic_proto_enabled) {
1124 		printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
1125 		return -1;
1126 	}
1127 
1128 #ifdef IPCONFIG_BOOTP
1129 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1130 		printk(KERN_ERR "DHCP/BOOTP: No suitable device found.\n");
1131 #endif
1132 #ifdef IPCONFIG_RARP
1133 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1134 		printk(KERN_ERR "RARP: No suitable device found.\n");
1135 #endif
1136 
1137 	if (!ic_proto_have_if)
1138 		/* Error message already printed */
1139 		return -1;
1140 
1141 	/*
1142 	 * Setup protocols
1143 	 */
1144 #ifdef IPCONFIG_BOOTP
1145 	if (do_bootp)
1146 		ic_bootp_init();
1147 #endif
1148 #ifdef IPCONFIG_RARP
1149 	if (do_rarp)
1150 		ic_rarp_init();
1151 #endif
1152 
1153 	/*
1154 	 * Send requests and wait, until we get an answer. This loop
1155 	 * seems to be a terrible waste of CPU time, but actually there is
1156 	 * only one process running at all, so we don't need to use any
1157 	 * scheduler functions.
1158 	 * [Actually we could now, but the nothing else running note still
1159 	 *  applies.. - AC]
1160 	 */
1161 	printk(KERN_NOTICE "Sending %s%s%s requests .",
1162 	       do_bootp
1163 		? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1164 	       (do_bootp && do_rarp) ? " and " : "",
1165 	       do_rarp ? "RARP" : "");
1166 
1167 	start_jiffies = jiffies;
1168 	d = ic_first_dev;
1169 	retries = CONF_SEND_RETRIES;
1170 	get_random_bytes(&timeout, sizeof(timeout));
1171 	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned) CONF_TIMEOUT_RANDOM);
1172 	for (;;) {
1173 		/* Track the device we are configuring */
1174 		ic_dev_xid = d->xid;
1175 
1176 #ifdef IPCONFIG_BOOTP
1177 		if (do_bootp && (d->able & IC_BOOTP))
1178 			ic_bootp_send_if(d, jiffies - start_jiffies);
1179 #endif
1180 #ifdef IPCONFIG_RARP
1181 		if (do_rarp && (d->able & IC_RARP))
1182 			ic_rarp_send_if(d);
1183 #endif
1184 
1185 		jiff = jiffies + (d->next ? CONF_INTER_TIMEOUT : timeout);
1186 		while (time_before(jiffies, jiff) && !ic_got_reply)
1187 			schedule_timeout_uninterruptible(1);
1188 #ifdef IPCONFIG_DHCP
1189 		/* DHCP isn't done until we get a DHCPACK. */
1190 		if ((ic_got_reply & IC_BOOTP) &&
1191 		    (ic_proto_enabled & IC_USE_DHCP) &&
1192 		    ic_dhcp_msgtype != DHCPACK) {
1193 			ic_got_reply = 0;
1194 			printk(KERN_CONT ",");
1195 			continue;
1196 		}
1197 #endif /* IPCONFIG_DHCP */
1198 
1199 		if (ic_got_reply) {
1200 			printk(KERN_CONT " OK\n");
1201 			break;
1202 		}
1203 
1204 		if ((d = d->next))
1205 			continue;
1206 
1207 		if (! --retries) {
1208 			printk(KERN_CONT " timed out!\n");
1209 			break;
1210 		}
1211 
1212 		d = ic_first_dev;
1213 
1214 		timeout = timeout CONF_TIMEOUT_MULT;
1215 		if (timeout > CONF_TIMEOUT_MAX)
1216 			timeout = CONF_TIMEOUT_MAX;
1217 
1218 		printk(KERN_CONT ".");
1219 	}
1220 
1221 #ifdef IPCONFIG_BOOTP
1222 	if (do_bootp)
1223 		ic_bootp_cleanup();
1224 #endif
1225 #ifdef IPCONFIG_RARP
1226 	if (do_rarp)
1227 		ic_rarp_cleanup();
1228 #endif
1229 
1230 	if (!ic_got_reply) {
1231 		ic_myaddr = NONE;
1232 		return -1;
1233 	}
1234 
1235 	printk("IP-Config: Got %s answer from %pI4, ",
1236 		((ic_got_reply & IC_RARP) ? "RARP"
1237 		 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1238 		&ic_servaddr);
1239 	printk(KERN_CONT "my address is %pI4\n", &ic_myaddr);
1240 
1241 	return 0;
1242 }
1243 
1244 #endif /* IPCONFIG_DYNAMIC */
1245 
1246 #ifdef CONFIG_PROC_FS
1247 
pnp_seq_show(struct seq_file * seq,void * v)1248 static int pnp_seq_show(struct seq_file *seq, void *v)
1249 {
1250 	int i;
1251 
1252 	if (ic_proto_used & IC_PROTO)
1253 		seq_printf(seq, "#PROTO: %s\n",
1254 			   (ic_proto_used & IC_RARP) ? "RARP"
1255 			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1256 	else
1257 		seq_puts(seq, "#MANUAL\n");
1258 
1259 	if (ic_domain[0])
1260 		seq_printf(seq,
1261 			   "domain %s\n", ic_domain);
1262 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1263 		if (ic_nameservers[i] != NONE)
1264 			seq_printf(seq, "nameserver %pI4\n",
1265 				   &ic_nameservers[i]);
1266 	}
1267 	if (ic_servaddr != NONE)
1268 		seq_printf(seq, "bootserver %pI4\n",
1269 			   &ic_servaddr);
1270 	return 0;
1271 }
1272 
pnp_seq_open(struct inode * indoe,struct file * file)1273 static int pnp_seq_open(struct inode *indoe, struct file *file)
1274 {
1275 	return single_open(file, pnp_seq_show, NULL);
1276 }
1277 
1278 static const struct file_operations pnp_seq_fops = {
1279 	.owner		= THIS_MODULE,
1280 	.open		= pnp_seq_open,
1281 	.read		= seq_read,
1282 	.llseek		= seq_lseek,
1283 	.release	= single_release,
1284 };
1285 #endif /* CONFIG_PROC_FS */
1286 
1287 /*
1288  *  Extract IP address from the parameter string if needed. Note that we
1289  *  need to have root_server_addr set _before_ IPConfig gets called as it
1290  *  can override it.
1291  */
root_nfs_parse_addr(char * name)1292 __be32 __init root_nfs_parse_addr(char *name)
1293 {
1294 	__be32 addr;
1295 	int octets = 0;
1296 	char *cp, *cq;
1297 
1298 	cp = cq = name;
1299 	while (octets < 4) {
1300 		while (*cp >= '0' && *cp <= '9')
1301 			cp++;
1302 		if (cp == cq || cp - cq > 3)
1303 			break;
1304 		if (*cp == '.' || octets == 3)
1305 			octets++;
1306 		if (octets < 4)
1307 			cp++;
1308 		cq = cp;
1309 	}
1310 	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1311 		if (*cp == ':')
1312 			*cp++ = '\0';
1313 		addr = in_aton(name);
1314 		memmove(name, cp, strlen(cp) + 1);
1315 	} else
1316 		addr = NONE;
1317 
1318 	return addr;
1319 }
1320 
1321 #define DEVICE_WAIT_MAX		12 /* 12 seconds */
1322 
wait_for_devices(void)1323 static int __init wait_for_devices(void)
1324 {
1325 	int i;
1326 
1327 	msleep(CONF_PRE_OPEN);
1328 	for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1329 		struct net_device *dev;
1330 		int found = 0;
1331 
1332 		rtnl_lock();
1333 		for_each_netdev(&init_net, dev) {
1334 			if (ic_device_match(dev)) {
1335 				found = 1;
1336 				break;
1337 			}
1338 		}
1339 		rtnl_unlock();
1340 		if (found)
1341 			return 0;
1342 		ssleep(1);
1343 	}
1344 	return -ENODEV;
1345 }
1346 
1347 /*
1348  *	IP Autoconfig dispatcher.
1349  */
1350 
ip_auto_config(void)1351 static int __init ip_auto_config(void)
1352 {
1353 	__be32 addr;
1354 #ifdef IPCONFIG_DYNAMIC
1355 	int retries = CONF_OPEN_RETRIES;
1356 #endif
1357 	int err;
1358 
1359 #ifdef CONFIG_PROC_FS
1360 	proc_net_fops_create(&init_net, "pnp", S_IRUGO, &pnp_seq_fops);
1361 #endif /* CONFIG_PROC_FS */
1362 
1363 	if (!ic_enable)
1364 		return 0;
1365 
1366 	DBG(("IP-Config: Entered.\n"));
1367 #ifdef IPCONFIG_DYNAMIC
1368  try_try_again:
1369 #endif
1370 	/* Wait for devices to appear */
1371 	err = wait_for_devices();
1372 	if (err)
1373 		return err;
1374 
1375 	/* Setup all network devices */
1376 	err = ic_open_devs();
1377 	if (err)
1378 		return err;
1379 
1380 	/* Give drivers a chance to settle */
1381 	ssleep(CONF_POST_OPEN);
1382 
1383 	/*
1384 	 * If the config information is insufficient (e.g., our IP address or
1385 	 * IP address of the boot server is missing or we have multiple network
1386 	 * interfaces and no default was set), use BOOTP or RARP to get the
1387 	 * missing values.
1388 	 */
1389 	if (ic_myaddr == NONE ||
1390 #ifdef CONFIG_ROOT_NFS
1391 	    (root_server_addr == NONE &&
1392 	     ic_servaddr == NONE &&
1393 	     ROOT_DEV == Root_NFS) ||
1394 #endif
1395 	    ic_first_dev->next) {
1396 #ifdef IPCONFIG_DYNAMIC
1397 		if (ic_dynamic() < 0) {
1398 			ic_close_devs();
1399 
1400 			/*
1401 			 * I don't know why, but sometimes the
1402 			 * eepro100 driver (at least) gets upset and
1403 			 * doesn't work the first time it's opened.
1404 			 * But then if you close it and reopen it, it
1405 			 * works just fine.  So we need to try that at
1406 			 * least once before giving up.
1407 			 *
1408 			 * Also, if the root will be NFS-mounted, we
1409 			 * have nowhere to go if DHCP fails.  So we
1410 			 * just have to keep trying forever.
1411 			 *
1412 			 * 				-- Chip
1413 			 */
1414 #ifdef CONFIG_ROOT_NFS
1415 			if (ROOT_DEV ==  Root_NFS) {
1416 				printk(KERN_ERR
1417 					"IP-Config: Retrying forever (NFS root)...\n");
1418 				goto try_try_again;
1419 			}
1420 #endif
1421 
1422 			if (--retries) {
1423 				printk(KERN_ERR
1424 				       "IP-Config: Reopening network devices...\n");
1425 				goto try_try_again;
1426 			}
1427 
1428 			/* Oh, well.  At least we tried. */
1429 			printk(KERN_ERR "IP-Config: Auto-configuration of network failed.\n");
1430 			return -1;
1431 		}
1432 #else /* !DYNAMIC */
1433 		printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
1434 		ic_close_devs();
1435 		return -1;
1436 #endif /* IPCONFIG_DYNAMIC */
1437 	} else {
1438 		/* Device selected manually or only one device -> use it */
1439 		ic_dev = ic_first_dev->dev;
1440 	}
1441 
1442 	addr = root_nfs_parse_addr(root_server_path);
1443 	if (root_server_addr == NONE)
1444 		root_server_addr = addr;
1445 
1446 	/*
1447 	 * Use defaults wherever applicable.
1448 	 */
1449 	if (ic_defaults() < 0)
1450 		return -1;
1451 
1452 	/*
1453 	 * Close all network devices except the device we've
1454 	 * autoconfigured and set up routes.
1455 	 */
1456 	ic_close_devs();
1457 	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1458 		return -1;
1459 
1460 	/*
1461 	 * Record which protocol was actually used.
1462 	 */
1463 #ifdef IPCONFIG_DYNAMIC
1464 	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1465 #endif
1466 
1467 #ifndef IPCONFIG_SILENT
1468 	/*
1469 	 * Clue in the operator.
1470 	 */
1471 	printk("IP-Config: Complete:\n");
1472 	printk("     device=%s", ic_dev->name);
1473 	printk(KERN_CONT ", addr=%pI4", &ic_myaddr);
1474 	printk(KERN_CONT ", mask=%pI4", &ic_netmask);
1475 	printk(KERN_CONT ", gw=%pI4", &ic_gateway);
1476 	printk(KERN_CONT ",\n     host=%s, domain=%s, nis-domain=%s",
1477 	       utsname()->nodename, ic_domain, utsname()->domainname);
1478 	printk(KERN_CONT ",\n     bootserver=%pI4", &ic_servaddr);
1479 	printk(KERN_CONT ", rootserver=%pI4", &root_server_addr);
1480 	printk(KERN_CONT ", rootpath=%s", root_server_path);
1481 	if (ic_dev_mtu)
1482 		printk(KERN_CONT ", mtu=%d", ic_dev_mtu);
1483 	printk(KERN_CONT "\n");
1484 #endif /* !SILENT */
1485 
1486 	return 0;
1487 }
1488 
1489 late_initcall(ip_auto_config);
1490 
1491 
1492 /*
1493  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1494  *  command line parameter.  See Documentation/filesystems/nfs/nfsroot.txt.
1495  */
ic_proto_name(char * name)1496 static int __init ic_proto_name(char *name)
1497 {
1498 	if (!strcmp(name, "on") || !strcmp(name, "any")) {
1499 		return 1;
1500 	}
1501 	if (!strcmp(name, "off") || !strcmp(name, "none")) {
1502 		return 0;
1503 	}
1504 #ifdef CONFIG_IP_PNP_DHCP
1505 	else if (!strcmp(name, "dhcp")) {
1506 		ic_proto_enabled &= ~IC_RARP;
1507 		return 1;
1508 	}
1509 #endif
1510 #ifdef CONFIG_IP_PNP_BOOTP
1511 	else if (!strcmp(name, "bootp")) {
1512 		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1513 		return 1;
1514 	}
1515 #endif
1516 #ifdef CONFIG_IP_PNP_RARP
1517 	else if (!strcmp(name, "rarp")) {
1518 		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1519 		return 1;
1520 	}
1521 #endif
1522 #ifdef IPCONFIG_DYNAMIC
1523 	else if (!strcmp(name, "both")) {
1524 		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1525 		return 1;
1526 	}
1527 #endif
1528 	return 0;
1529 }
1530 
ip_auto_config_setup(char * addrs)1531 static int __init ip_auto_config_setup(char *addrs)
1532 {
1533 	char *cp, *ip, *dp;
1534 	int num = 0;
1535 
1536 	ic_set_manually = 1;
1537 	ic_enable = 1;
1538 
1539 	/*
1540 	 * If any dhcp, bootp etc options are set, leave autoconfig on
1541 	 * and skip the below static IP processing.
1542 	 */
1543 	if (ic_proto_name(addrs))
1544 		return 1;
1545 
1546 	/* If no static IP is given, turn off autoconfig and bail.  */
1547 	if (*addrs == 0 ||
1548 	    strcmp(addrs, "off") == 0 ||
1549 	    strcmp(addrs, "none") == 0) {
1550 		ic_enable = 0;
1551 		return 1;
1552 	}
1553 
1554 	/* Parse string for static IP assignment.  */
1555 	ip = addrs;
1556 	while (ip && *ip) {
1557 		if ((cp = strchr(ip, ':')))
1558 			*cp++ = '\0';
1559 		if (strlen(ip) > 0) {
1560 			DBG(("IP-Config: Parameter #%d: `%s'\n", num, ip));
1561 			switch (num) {
1562 			case 0:
1563 				if ((ic_myaddr = in_aton(ip)) == ANY)
1564 					ic_myaddr = NONE;
1565 				break;
1566 			case 1:
1567 				if ((ic_servaddr = in_aton(ip)) == ANY)
1568 					ic_servaddr = NONE;
1569 				break;
1570 			case 2:
1571 				if ((ic_gateway = in_aton(ip)) == ANY)
1572 					ic_gateway = NONE;
1573 				break;
1574 			case 3:
1575 				if ((ic_netmask = in_aton(ip)) == ANY)
1576 					ic_netmask = NONE;
1577 				break;
1578 			case 4:
1579 				if ((dp = strchr(ip, '.'))) {
1580 					*dp++ = '\0';
1581 					strlcpy(utsname()->domainname, dp,
1582 						sizeof(utsname()->domainname));
1583 				}
1584 				strlcpy(utsname()->nodename, ip,
1585 					sizeof(utsname()->nodename));
1586 				ic_host_name_set = 1;
1587 				break;
1588 			case 5:
1589 				strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1590 				break;
1591 			case 6:
1592 				if (ic_proto_name(ip) == 0 &&
1593 				    ic_myaddr == NONE) {
1594 					ic_enable = 0;
1595 				}
1596 				break;
1597 			}
1598 		}
1599 		ip = cp;
1600 		num++;
1601 	}
1602 
1603 	return 1;
1604 }
1605 
nfsaddrs_config_setup(char * addrs)1606 static int __init nfsaddrs_config_setup(char *addrs)
1607 {
1608 	return ip_auto_config_setup(addrs);
1609 }
1610 
vendor_class_identifier_setup(char * addrs)1611 static int __init vendor_class_identifier_setup(char *addrs)
1612 {
1613 	if (strlcpy(vendor_class_identifier, addrs,
1614 		    sizeof(vendor_class_identifier))
1615 	    >= sizeof(vendor_class_identifier))
1616 		printk(KERN_WARNING "DHCP: vendorclass too long, truncated to \"%s\"",
1617 		       vendor_class_identifier);
1618 	return 1;
1619 }
1620 
1621 __setup("ip=", ip_auto_config_setup);
1622 __setup("nfsaddrs=", nfsaddrs_config_setup);
1623 __setup("dhcpclass=", vendor_class_identifier_setup);
1624