xref: /linux/net/ipv4/ipconfig.c (revision 9190d4a263264eabf715f5fc1827da45e3fdc247)
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/ip.h>
65 #include <net/ipconfig.h>
66 #include <net/route.h>
67 
68 #include <linux/uaccess.h>
69 #include <net/checksum.h>
70 #include <asm/processor.h>
71 
72 #if defined(CONFIG_IP_PNP_DHCP)
73 #define IPCONFIG_DHCP
74 #endif
75 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
76 #define IPCONFIG_BOOTP
77 #endif
78 #if defined(CONFIG_IP_PNP_RARP)
79 #define IPCONFIG_RARP
80 #endif
81 #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
82 #define IPCONFIG_DYNAMIC
83 #endif
84 
85 /* Define the friendly delay before and after opening net devices */
86 #define CONF_POST_OPEN		10	/* After opening: 10 msecs */
87 
88 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
89 #define CONF_OPEN_RETRIES 	2	/* (Re)open devices twice */
90 #define CONF_SEND_RETRIES 	6	/* Send six requests per open */
91 #define CONF_BASE_TIMEOUT	(HZ*2)	/* Initial timeout: 2 seconds */
92 #define CONF_TIMEOUT_RANDOM	(HZ)	/* Maximum amount of randomization */
93 #define CONF_TIMEOUT_MULT	*7/4	/* Rate of timeout growth */
94 #define CONF_TIMEOUT_MAX	(HZ*30)	/* Maximum allowed timeout */
95 #define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
96 					   - '3' from resolv.h */
97 #define CONF_NTP_SERVERS_MAX   3	/* Maximum number of NTP servers */
98 
99 #define NONE cpu_to_be32(INADDR_NONE)
100 #define ANY cpu_to_be32(INADDR_ANY)
101 
102 /* Wait for carrier timeout default in seconds */
103 static unsigned int carrier_timeout = 120;
104 
105 /*
106  * Public IP configuration
107  */
108 
109 /* This is used by platforms which might be able to set the ipconfig
110  * variables using firmware environment vars.  If this is set, it will
111  * ignore such firmware variables.
112  */
113 int ic_set_manually __initdata = 0;		/* IPconfig parameters set manually */
114 
115 static int ic_enable __initdata;		/* IP config enabled? */
116 
117 /* Protocol choice */
118 int ic_proto_enabled __initdata = 0
119 #ifdef IPCONFIG_BOOTP
120 			| IC_BOOTP
121 #endif
122 #ifdef CONFIG_IP_PNP_DHCP
123 			| IC_USE_DHCP
124 #endif
125 #ifdef IPCONFIG_RARP
126 			| IC_RARP
127 #endif
128 			;
129 
130 static int ic_host_name_set __initdata;	/* Host name set by us? */
131 
132 __be32 ic_myaddr = NONE;		/* My IP address */
133 static __be32 ic_netmask = NONE;	/* Netmask for local subnet */
134 __be32 ic_gateway = NONE;	/* Gateway IP address */
135 
136 #ifdef IPCONFIG_DYNAMIC
137 static __be32 ic_addrservaddr = NONE;	/* IP Address of the IP addresses'server */
138 #endif
139 
140 __be32 ic_servaddr = NONE;	/* Boot server IP address */
141 
142 __be32 root_server_addr = NONE;	/* Address of NFS server */
143 u8 root_server_path[256] = { 0, };	/* Path to mount as root */
144 
145 /* vendor class identifier */
146 static char vendor_class_identifier[253] __initdata;
147 
148 #if defined(CONFIG_IP_PNP_DHCP)
149 static char dhcp_client_identifier[253] __initdata;
150 #endif
151 
152 /* Persistent data: */
153 
154 #ifdef IPCONFIG_DYNAMIC
155 static int ic_proto_used;			/* Protocol used, if any */
156 #else
157 #define ic_proto_used 0
158 #endif
159 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
160 static __be32 ic_ntp_servers[CONF_NTP_SERVERS_MAX]; /* NTP server IP addresses */
161 static u8 ic_domain[64];		/* DNS (not NIS) domain name */
162 
163 /*
164  * Private state.
165  */
166 
167 /* Name of user-selected boot device */
168 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
169 
170 /* Protocols supported by available interfaces */
171 static int ic_proto_have_if __initdata;
172 
173 /* MTU for boot device */
174 static int ic_dev_mtu __initdata;
175 
176 #ifdef IPCONFIG_DYNAMIC
177 static DEFINE_SPINLOCK(ic_recv_lock);
178 static volatile int ic_got_reply __initdata;    /* Proto(s) that replied */
179 #endif
180 #ifdef IPCONFIG_DHCP
181 static int ic_dhcp_msgtype __initdata;	/* DHCP msg type received */
182 #endif
183 
184 
185 /*
186  *	Network devices
187  */
188 
189 struct ic_device {
190 	struct ic_device *next;
191 	struct net_device *dev;
192 	unsigned short flags;
193 	short able;
194 	__be32 xid;
195 };
196 
197 static struct ic_device *ic_first_dev __initdata;	/* List of open device */
198 static struct ic_device *ic_dev __initdata;		/* Selected device */
199 
200 static bool __init ic_is_init_dev(struct net_device *dev)
201 {
202 	if (dev->flags & IFF_LOOPBACK)
203 		return false;
204 	return user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
205 	    (!(dev->flags & IFF_LOOPBACK) &&
206 	     (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
207 	     strncmp(dev->name, "dummy", 5));
208 }
209 
210 static int __init ic_open_devs(void)
211 {
212 	struct ic_device *d, **last;
213 	struct net_device *dev;
214 	unsigned short oflags;
215 	unsigned long start, next_msg;
216 
217 	last = &ic_first_dev;
218 	rtnl_lock();
219 
220 	/* bring loopback device up first */
221 	for_each_netdev(&init_net, dev) {
222 		if (!(dev->flags & IFF_LOOPBACK))
223 			continue;
224 		if (dev_change_flags(dev, dev->flags | IFF_UP, NULL) < 0)
225 			pr_err("IP-Config: Failed to open %s\n", dev->name);
226 	}
227 
228 	for_each_netdev(&init_net, dev) {
229 		if (ic_is_init_dev(dev)) {
230 			int able = 0;
231 			if (dev->mtu >= 364)
232 				able |= IC_BOOTP;
233 			else
234 				pr_warn("DHCP/BOOTP: Ignoring device %s, MTU %d too small\n",
235 					dev->name, dev->mtu);
236 			if (!(dev->flags & IFF_NOARP))
237 				able |= IC_RARP;
238 			able &= ic_proto_enabled;
239 			if (ic_proto_enabled && !able)
240 				continue;
241 			oflags = dev->flags;
242 			if (dev_change_flags(dev, oflags | IFF_UP, NULL) < 0) {
243 				pr_err("IP-Config: Failed to open %s\n",
244 				       dev->name);
245 				continue;
246 			}
247 			if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
248 				rtnl_unlock();
249 				return -ENOMEM;
250 			}
251 			d->dev = dev;
252 			*last = d;
253 			last = &d->next;
254 			d->flags = oflags;
255 			d->able = able;
256 			if (able & IC_BOOTP)
257 				get_random_bytes(&d->xid, sizeof(__be32));
258 			else
259 				d->xid = 0;
260 			ic_proto_have_if |= able;
261 			pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n",
262 				 dev->name, able, d->xid);
263 		}
264 	}
265 	/* Devices with a complex topology like SFP ethernet interfaces needs
266 	 * the rtnl_lock at init. The carrier wait-loop must therefore run
267 	 * without holding it.
268 	 */
269 	rtnl_unlock();
270 
271 	/* no point in waiting if we could not bring up at least one device */
272 	if (!ic_first_dev)
273 		goto have_carrier;
274 
275 	/* wait for a carrier on at least one device */
276 	start = jiffies;
277 	next_msg = start + msecs_to_jiffies(20000);
278 	while (time_before(jiffies, start +
279 			   msecs_to_jiffies(carrier_timeout * 1000))) {
280 		int wait, elapsed;
281 
282 		rtnl_lock();
283 		for_each_netdev(&init_net, dev)
284 			if (ic_is_init_dev(dev) && netif_carrier_ok(dev)) {
285 				rtnl_unlock();
286 				goto have_carrier;
287 			}
288 		rtnl_unlock();
289 
290 		msleep(1);
291 
292 		if (time_before(jiffies, next_msg))
293 			continue;
294 
295 		elapsed = jiffies_to_msecs(jiffies - start);
296 		wait = (carrier_timeout * 1000 - elapsed + 500) / 1000;
297 		pr_info("Waiting up to %d more seconds for network.\n", wait);
298 		next_msg = jiffies + msecs_to_jiffies(20000);
299 	}
300 have_carrier:
301 
302 	*last = NULL;
303 
304 	if (!ic_first_dev) {
305 		if (user_dev_name[0])
306 			pr_err("IP-Config: Device `%s' not found\n",
307 			       user_dev_name);
308 		else
309 			pr_err("IP-Config: No network devices available\n");
310 		return -ENODEV;
311 	}
312 	return 0;
313 }
314 
315 /* Close all network interfaces except the one we've autoconfigured, and its
316  * lowers, in case it's a stacked virtual interface.
317  */
318 static void __init ic_close_devs(void)
319 {
320 	struct net_device *selected_dev = ic_dev ? ic_dev->dev : NULL;
321 	struct ic_device *d, *next;
322 	struct net_device *dev;
323 
324 	rtnl_lock();
325 	next = ic_first_dev;
326 	while ((d = next)) {
327 		bool bring_down = (d != ic_dev);
328 		struct net_device *lower;
329 		struct list_head *iter;
330 
331 		next = d->next;
332 		dev = d->dev;
333 
334 		if (selected_dev) {
335 			netdev_for_each_lower_dev(selected_dev, lower, iter) {
336 				if (dev == lower) {
337 					bring_down = false;
338 					break;
339 				}
340 			}
341 		}
342 		if (bring_down) {
343 			pr_debug("IP-Config: Downing %s\n", dev->name);
344 			dev_change_flags(dev, d->flags, NULL);
345 		}
346 		kfree(d);
347 	}
348 	rtnl_unlock();
349 }
350 
351 /*
352  *	Interface to various network functions.
353  */
354 
355 static inline void
356 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
357 {
358 	sin->sin_family = AF_INET;
359 	sin->sin_addr.s_addr = addr;
360 	sin->sin_port = port;
361 }
362 
363 /*
364  *	Set up interface addresses and routes.
365  */
366 
367 static int __init ic_setup_if(void)
368 {
369 	struct ifreq ir;
370 	struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
371 	int err;
372 
373 	memset(&ir, 0, sizeof(ir));
374 	strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name);
375 	set_sockaddr(sin, ic_myaddr, 0);
376 	if ((err = devinet_ioctl(&init_net, SIOCSIFADDR, &ir)) < 0) {
377 		pr_err("IP-Config: Unable to set interface address (%d)\n",
378 		       err);
379 		return -1;
380 	}
381 	set_sockaddr(sin, ic_netmask, 0);
382 	if ((err = devinet_ioctl(&init_net, SIOCSIFNETMASK, &ir)) < 0) {
383 		pr_err("IP-Config: Unable to set interface netmask (%d)\n",
384 		       err);
385 		return -1;
386 	}
387 	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
388 	if ((err = devinet_ioctl(&init_net, SIOCSIFBRDADDR, &ir)) < 0) {
389 		pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
390 		       err);
391 		return -1;
392 	}
393 	/* Handle the case where we need non-standard MTU on the boot link (a network
394 	 * using jumbo frames, for instance).  If we can't set the mtu, don't error
395 	 * out, we'll try to muddle along.
396 	 */
397 	if (ic_dev_mtu != 0) {
398 		rtnl_lock();
399 		if ((err = dev_set_mtu(ic_dev->dev, ic_dev_mtu)) < 0)
400 			pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
401 			       ic_dev_mtu, err);
402 		rtnl_unlock();
403 	}
404 	return 0;
405 }
406 
407 static int __init ic_setup_routes(void)
408 {
409 	/* No need to setup device routes, only the default route... */
410 
411 	if (ic_gateway != NONE) {
412 		struct rtentry rm;
413 		int err;
414 
415 		memset(&rm, 0, sizeof(rm));
416 		if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
417 			pr_err("IP-Config: Gateway not on directly connected network\n");
418 			return -1;
419 		}
420 		set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
421 		set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
422 		set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
423 		rm.rt_flags = RTF_UP | RTF_GATEWAY;
424 		if ((err = ip_rt_ioctl(&init_net, SIOCADDRT, &rm)) < 0) {
425 			pr_err("IP-Config: Cannot add default route (%d)\n",
426 			       err);
427 			return -1;
428 		}
429 	}
430 
431 	return 0;
432 }
433 
434 /*
435  *	Fill in default values for all missing parameters.
436  */
437 
438 static int __init ic_defaults(void)
439 {
440 	/*
441 	 *	At this point we have no userspace running so need not
442 	 *	claim locks on system_utsname
443 	 */
444 
445 	if (!ic_host_name_set)
446 		sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
447 
448 	if (root_server_addr == NONE)
449 		root_server_addr = ic_servaddr;
450 
451 	if (ic_netmask == NONE) {
452 		if (IN_CLASSA(ntohl(ic_myaddr)))
453 			ic_netmask = htonl(IN_CLASSA_NET);
454 		else if (IN_CLASSB(ntohl(ic_myaddr)))
455 			ic_netmask = htonl(IN_CLASSB_NET);
456 		else if (IN_CLASSC(ntohl(ic_myaddr)))
457 			ic_netmask = htonl(IN_CLASSC_NET);
458 		else if (IN_CLASSE(ntohl(ic_myaddr)))
459 			ic_netmask = htonl(IN_CLASSE_NET);
460 		else {
461 			pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
462 			       &ic_myaddr);
463 			return -1;
464 		}
465 		pr_notice("IP-Config: Guessing netmask %pI4\n",
466 			  &ic_netmask);
467 	}
468 
469 	return 0;
470 }
471 
472 /*
473  *	RARP support.
474  */
475 
476 #ifdef IPCONFIG_RARP
477 
478 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
479 
480 static struct packet_type rarp_packet_type __initdata = {
481 	.type =	cpu_to_be16(ETH_P_RARP),
482 	.func =	ic_rarp_recv,
483 };
484 
485 static inline void __init ic_rarp_init(void)
486 {
487 	dev_add_pack(&rarp_packet_type);
488 }
489 
490 static inline void __init ic_rarp_cleanup(void)
491 {
492 	dev_remove_pack(&rarp_packet_type);
493 }
494 
495 /*
496  *  Process received RARP packet.
497  */
498 static int __init
499 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
500 {
501 	struct arphdr *rarp;
502 	unsigned char *rarp_ptr;
503 	__be32 sip, tip;
504 	unsigned char *tha;		/* t for "target" */
505 	struct ic_device *d;
506 
507 	if (!net_eq(dev_net(dev), &init_net))
508 		goto drop;
509 
510 	skb = skb_share_check(skb, GFP_ATOMIC);
511 	if (!skb)
512 		return NET_RX_DROP;
513 
514 	if (!pskb_may_pull(skb, sizeof(struct arphdr)))
515 		goto drop;
516 
517 	/* Basic sanity checks can be done without the lock.  */
518 	rarp = (struct arphdr *)skb_transport_header(skb);
519 
520 	/* If this test doesn't pass, it's not IP, or we should
521 	 * ignore it anyway.
522 	 */
523 	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
524 		goto drop;
525 
526 	/* If it's not a RARP reply, delete it. */
527 	if (rarp->ar_op != htons(ARPOP_RREPLY))
528 		goto drop;
529 
530 	/* If it's not Ethernet, delete it. */
531 	if (rarp->ar_pro != htons(ETH_P_IP))
532 		goto drop;
533 
534 	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
535 		goto drop;
536 
537 	/* OK, it is all there and looks valid, process... */
538 	rarp = (struct arphdr *)skb_transport_header(skb);
539 	rarp_ptr = (unsigned char *) (rarp + 1);
540 
541 	/* One reply at a time, please. */
542 	spin_lock(&ic_recv_lock);
543 
544 	/* If we already have a reply, just drop the packet */
545 	if (ic_got_reply)
546 		goto drop_unlock;
547 
548 	/* Find the ic_device that the packet arrived on */
549 	d = ic_first_dev;
550 	while (d && d->dev != dev)
551 		d = d->next;
552 	if (!d)
553 		goto drop_unlock;	/* should never happen */
554 
555 	/* Extract variable-width fields */
556 	rarp_ptr += dev->addr_len;
557 	memcpy(&sip, rarp_ptr, 4);
558 	rarp_ptr += 4;
559 	tha = rarp_ptr;
560 	rarp_ptr += dev->addr_len;
561 	memcpy(&tip, rarp_ptr, 4);
562 
563 	/* Discard packets which are not meant for us. */
564 	if (memcmp(tha, dev->dev_addr, dev->addr_len))
565 		goto drop_unlock;
566 
567 	/* Discard packets which are not from specified server. */
568 	if (ic_servaddr != NONE && ic_servaddr != sip)
569 		goto drop_unlock;
570 
571 	/* We have a winner! */
572 	ic_dev = d;
573 	if (ic_myaddr == NONE)
574 		ic_myaddr = tip;
575 	ic_servaddr = sip;
576 	ic_addrservaddr = sip;
577 	ic_got_reply = IC_RARP;
578 
579 drop_unlock:
580 	/* Show's over.  Nothing to see here.  */
581 	spin_unlock(&ic_recv_lock);
582 
583 drop:
584 	/* Throw the packet out. */
585 	kfree_skb(skb);
586 	return 0;
587 }
588 
589 
590 /*
591  *  Send RARP request packet over a single interface.
592  */
593 static void __init ic_rarp_send_if(struct ic_device *d)
594 {
595 	struct net_device *dev = d->dev;
596 	arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
597 		 dev->dev_addr, dev->dev_addr);
598 }
599 #endif
600 
601 /*
602  *  Predefine Nameservers
603  */
604 static inline void __init ic_nameservers_predef(void)
605 {
606 	int i;
607 
608 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
609 		ic_nameservers[i] = NONE;
610 }
611 
612 /* Predefine NTP servers */
613 static inline void __init ic_ntp_servers_predef(void)
614 {
615 	int i;
616 
617 	for (i = 0; i < CONF_NTP_SERVERS_MAX; i++)
618 		ic_ntp_servers[i] = NONE;
619 }
620 
621 /*
622  *	DHCP/BOOTP support.
623  */
624 
625 #ifdef IPCONFIG_BOOTP
626 
627 struct bootp_pkt {		/* BOOTP packet format */
628 	struct iphdr iph;	/* IP header */
629 	struct udphdr udph;	/* UDP header */
630 	u8 op;			/* 1=request, 2=reply */
631 	u8 htype;		/* HW address type */
632 	u8 hlen;		/* HW address length */
633 	u8 hops;		/* Used only by gateways */
634 	__be32 xid;		/* Transaction ID */
635 	__be16 secs;		/* Seconds since we started */
636 	__be16 flags;		/* Just what it says */
637 	__be32 client_ip;		/* Client's IP address if known */
638 	__be32 your_ip;		/* Assigned IP address */
639 	__be32 server_ip;		/* (Next, e.g. NFS) Server's IP address */
640 	__be32 relay_ip;		/* IP address of BOOTP relay */
641 	u8 hw_addr[16];		/* Client's HW address */
642 	u8 serv_name[64];	/* Server host name */
643 	u8 boot_file[128];	/* Name of boot file */
644 	u8 exten[312];		/* DHCP options / BOOTP vendor extensions */
645 };
646 
647 /* packet ops */
648 #define BOOTP_REQUEST	1
649 #define BOOTP_REPLY	2
650 
651 /* DHCP message types */
652 #define DHCPDISCOVER	1
653 #define DHCPOFFER	2
654 #define DHCPREQUEST	3
655 #define DHCPDECLINE	4
656 #define DHCPACK		5
657 #define DHCPNAK		6
658 #define DHCPRELEASE	7
659 #define DHCPINFORM	8
660 
661 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
662 
663 static struct packet_type bootp_packet_type __initdata = {
664 	.type =	cpu_to_be16(ETH_P_IP),
665 	.func =	ic_bootp_recv,
666 };
667 
668 /*
669  *  Initialize DHCP/BOOTP extension fields in the request.
670  */
671 
672 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
673 
674 #ifdef IPCONFIG_DHCP
675 
676 static void __init
677 ic_dhcp_init_options(u8 *options, struct ic_device *d)
678 {
679 	u8 mt = ((ic_servaddr == NONE)
680 		 ? DHCPDISCOVER : DHCPREQUEST);
681 	u8 *e = options;
682 	int len;
683 
684 	pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
685 
686 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
687 	e += 4;
688 
689 	*e++ = 53;		/* DHCP message type */
690 	*e++ = 1;
691 	*e++ = mt;
692 
693 	if (mt == DHCPREQUEST) {
694 		*e++ = 54;	/* Server ID (IP address) */
695 		*e++ = 4;
696 		memcpy(e, &ic_servaddr, 4);
697 		e += 4;
698 
699 		*e++ = 50;	/* Requested IP address */
700 		*e++ = 4;
701 		memcpy(e, &ic_myaddr, 4);
702 		e += 4;
703 	}
704 
705 	/* always? */
706 	{
707 		static const u8 ic_req_params[] = {
708 			1,	/* Subnet mask */
709 			3,	/* Default gateway */
710 			6,	/* DNS server */
711 			12,	/* Host name */
712 			15,	/* Domain name */
713 			17,	/* Boot path */
714 			26,	/* MTU */
715 			40,	/* NIS domain name */
716 			42,	/* NTP servers */
717 		};
718 
719 		*e++ = 55;	/* Parameter request list */
720 		*e++ = sizeof(ic_req_params);
721 		memcpy(e, ic_req_params, sizeof(ic_req_params));
722 		e += sizeof(ic_req_params);
723 
724 		if (ic_host_name_set) {
725 			*e++ = 12;	/* host-name */
726 			len = strlen(utsname()->nodename);
727 			*e++ = len;
728 			memcpy(e, utsname()->nodename, len);
729 			e += len;
730 		}
731 		if (*vendor_class_identifier) {
732 			pr_info("DHCP: sending class identifier \"%s\"\n",
733 				vendor_class_identifier);
734 			*e++ = 60;	/* Class-identifier */
735 			len = strlen(vendor_class_identifier);
736 			*e++ = len;
737 			memcpy(e, vendor_class_identifier, len);
738 			e += len;
739 		}
740 		len = strlen(dhcp_client_identifier + 1);
741 		/* the minimum length of identifier is 2, include 1 byte type,
742 		 * and can not be larger than the length of options
743 		 */
744 		if (len >= 1 && len < 312 - (e - options) - 1) {
745 			*e++ = 61;
746 			*e++ = len + 1;
747 			memcpy(e, dhcp_client_identifier, len + 1);
748 			e += len + 1;
749 		}
750 	}
751 
752 	*e++ = 255;	/* End of the list */
753 }
754 
755 #endif /* IPCONFIG_DHCP */
756 
757 static void __init ic_bootp_init_ext(u8 *e)
758 {
759 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
760 	e += 4;
761 	*e++ = 1;		/* Subnet mask request */
762 	*e++ = 4;
763 	e += 4;
764 	*e++ = 3;		/* Default gateway request */
765 	*e++ = 4;
766 	e += 4;
767 #if CONF_NAMESERVERS_MAX > 0
768 	*e++ = 6;		/* (DNS) name server request */
769 	*e++ = 4 * CONF_NAMESERVERS_MAX;
770 	e += 4 * CONF_NAMESERVERS_MAX;
771 #endif
772 	*e++ = 12;		/* Host name request */
773 	*e++ = 32;
774 	e += 32;
775 	*e++ = 40;		/* NIS Domain name request */
776 	*e++ = 32;
777 	e += 32;
778 	*e++ = 17;		/* Boot path */
779 	*e++ = 40;
780 	e += 40;
781 
782 	*e++ = 57;		/* set extension buffer size for reply */
783 	*e++ = 2;
784 	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
785 	*e++ = 150;
786 
787 	*e++ = 255;		/* End of the list */
788 }
789 
790 
791 /*
792  *  Initialize the DHCP/BOOTP mechanism.
793  */
794 static inline void __init ic_bootp_init(void)
795 {
796 	/* Re-initialise all name servers and NTP servers to NONE, in case any
797 	 * were set via the "ip=" or "nfsaddrs=" kernel command line parameters:
798 	 * any IP addresses specified there will already have been decoded but
799 	 * are no longer needed
800 	 */
801 	ic_nameservers_predef();
802 	ic_ntp_servers_predef();
803 
804 	dev_add_pack(&bootp_packet_type);
805 }
806 
807 
808 /*
809  *  DHCP/BOOTP cleanup.
810  */
811 static inline void __init ic_bootp_cleanup(void)
812 {
813 	dev_remove_pack(&bootp_packet_type);
814 }
815 
816 
817 /*
818  *  Send DHCP/BOOTP request to single interface.
819  */
820 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
821 {
822 	struct net_device *dev = d->dev;
823 	struct sk_buff *skb;
824 	struct bootp_pkt *b;
825 	struct iphdr *h;
826 	int hlen = LL_RESERVED_SPACE(dev);
827 	int tlen = dev->needed_tailroom;
828 
829 	/* Allocate packet */
830 	skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
831 			GFP_KERNEL);
832 	if (!skb)
833 		return;
834 	skb_reserve(skb, hlen);
835 	b = skb_put_zero(skb, sizeof(struct bootp_pkt));
836 
837 	/* Construct IP header */
838 	skb_reset_network_header(skb);
839 	h = ip_hdr(skb);
840 	h->version = 4;
841 	h->ihl = 5;
842 	h->tot_len = htons(sizeof(struct bootp_pkt));
843 	h->frag_off = htons(IP_DF);
844 	h->ttl = 64;
845 	h->protocol = IPPROTO_UDP;
846 	h->daddr = htonl(INADDR_BROADCAST);
847 	h->check = ip_fast_csum((unsigned char *) h, h->ihl);
848 
849 	/* Construct UDP header */
850 	b->udph.source = htons(68);
851 	b->udph.dest = htons(67);
852 	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
853 	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
854 
855 	/* Construct DHCP/BOOTP header */
856 	b->op = BOOTP_REQUEST;
857 	if (dev->type < 256) /* check for false types */
858 		b->htype = dev->type;
859 	else if (dev->type == ARPHRD_FDDI)
860 		b->htype = ARPHRD_ETHER;
861 	else {
862 		pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
863 			dev->name);
864 		b->htype = dev->type; /* can cause undefined behavior */
865 	}
866 
867 	/* server_ip and your_ip address are both already zero per RFC2131 */
868 	b->hlen = dev->addr_len;
869 	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
870 	b->secs = htons(jiffies_diff / HZ);
871 	b->xid = d->xid;
872 
873 	/* add DHCP options or BOOTP extensions */
874 #ifdef IPCONFIG_DHCP
875 	if (ic_proto_enabled & IC_USE_DHCP)
876 		ic_dhcp_init_options(b->exten, d);
877 	else
878 #endif
879 		ic_bootp_init_ext(b->exten);
880 
881 	/* Chain packet down the line... */
882 	skb->dev = dev;
883 	skb->protocol = htons(ETH_P_IP);
884 	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
885 			    dev->broadcast, dev->dev_addr, skb->len) < 0) {
886 		kfree_skb(skb);
887 		printk("E");
888 		return;
889 	}
890 
891 	if (dev_queue_xmit(skb) < 0)
892 		printk("E");
893 }
894 
895 
896 /*
897  *  Copy BOOTP-supplied string
898  */
899 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
900 {
901 	if (!len)
902 		return 0;
903 	if (len > max-1)
904 		len = max-1;
905 	memcpy(dest, src, len);
906 	dest[len] = '\0';
907 	return 1;
908 }
909 
910 
911 /*
912  *  Process BOOTP extensions.
913  */
914 static void __init ic_do_bootp_ext(u8 *ext)
915 {
916 	u8 servers;
917 	int i;
918 	__be16 mtu;
919 
920 	u8 *c;
921 
922 	pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
923 	for (c=ext+2; c<ext+2+ext[1]; c++)
924 		pr_debug(" %02x", *c);
925 	pr_debug("\n");
926 
927 	switch (*ext++) {
928 	case 1:		/* Subnet mask */
929 		if (ic_netmask == NONE)
930 			memcpy(&ic_netmask, ext+1, 4);
931 		break;
932 	case 3:		/* Default gateway */
933 		if (ic_gateway == NONE)
934 			memcpy(&ic_gateway, ext+1, 4);
935 		break;
936 	case 6:		/* DNS server */
937 		servers= *ext/4;
938 		if (servers > CONF_NAMESERVERS_MAX)
939 			servers = CONF_NAMESERVERS_MAX;
940 		for (i = 0; i < servers; i++) {
941 			if (ic_nameservers[i] == NONE)
942 				memcpy(&ic_nameservers[i], ext+1+4*i, 4);
943 		}
944 		break;
945 	case 12:	/* Host name */
946 		if (!ic_host_name_set) {
947 			ic_bootp_string(utsname()->nodename, ext+1, *ext,
948 					__NEW_UTS_LEN);
949 			ic_host_name_set = 1;
950 		}
951 		break;
952 	case 15:	/* Domain name (DNS) */
953 		if (!ic_domain[0])
954 			ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
955 		break;
956 	case 17:	/* Root path */
957 		if (!root_server_path[0])
958 			ic_bootp_string(root_server_path, ext+1, *ext,
959 					sizeof(root_server_path));
960 		break;
961 	case 26:	/* Interface MTU */
962 		memcpy(&mtu, ext+1, sizeof(mtu));
963 		ic_dev_mtu = ntohs(mtu);
964 		break;
965 	case 40:	/* NIS Domain name (_not_ DNS) */
966 		ic_bootp_string(utsname()->domainname, ext+1, *ext,
967 				__NEW_UTS_LEN);
968 		break;
969 	case 42:	/* NTP servers */
970 		servers = *ext / 4;
971 		if (servers > CONF_NTP_SERVERS_MAX)
972 			servers = CONF_NTP_SERVERS_MAX;
973 		for (i = 0; i < servers; i++) {
974 			if (ic_ntp_servers[i] == NONE)
975 				memcpy(&ic_ntp_servers[i], ext+1+4*i, 4);
976 		}
977 		break;
978 	}
979 }
980 
981 
982 /*
983  *  Receive BOOTP reply.
984  */
985 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
986 {
987 	struct bootp_pkt *b;
988 	struct iphdr *h;
989 	struct ic_device *d;
990 	int len, ext_len;
991 
992 	if (!net_eq(dev_net(dev), &init_net))
993 		goto drop;
994 
995 	/* Perform verifications before taking the lock.  */
996 	if (skb->pkt_type == PACKET_OTHERHOST)
997 		goto drop;
998 
999 	skb = skb_share_check(skb, GFP_ATOMIC);
1000 	if (!skb)
1001 		return NET_RX_DROP;
1002 
1003 	if (!pskb_may_pull(skb,
1004 			   sizeof(struct iphdr) +
1005 			   sizeof(struct udphdr)))
1006 		goto drop;
1007 
1008 	b = (struct bootp_pkt *)skb_network_header(skb);
1009 	h = &b->iph;
1010 
1011 	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
1012 		goto drop;
1013 
1014 	/* Fragments are not supported */
1015 	if (ip_is_fragment(h)) {
1016 		net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
1017 		goto drop;
1018 	}
1019 
1020 	if (skb->len < ntohs(h->tot_len))
1021 		goto drop;
1022 
1023 	if (ip_fast_csum((char *) h, h->ihl))
1024 		goto drop;
1025 
1026 	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
1027 		goto drop;
1028 
1029 	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
1030 		goto drop;
1031 
1032 	len = ntohs(b->udph.len) - sizeof(struct udphdr);
1033 	ext_len = len - (sizeof(*b) -
1034 			 sizeof(struct iphdr) -
1035 			 sizeof(struct udphdr) -
1036 			 sizeof(b->exten));
1037 	if (ext_len < 0)
1038 		goto drop;
1039 
1040 	/* Ok the front looks good, make sure we can get at the rest.  */
1041 	if (!pskb_may_pull(skb, skb->len))
1042 		goto drop;
1043 
1044 	b = (struct bootp_pkt *)skb_network_header(skb);
1045 	h = &b->iph;
1046 
1047 	/* One reply at a time, please. */
1048 	spin_lock(&ic_recv_lock);
1049 
1050 	/* If we already have a reply, just drop the packet */
1051 	if (ic_got_reply)
1052 		goto drop_unlock;
1053 
1054 	/* Find the ic_device that the packet arrived on */
1055 	d = ic_first_dev;
1056 	while (d && d->dev != dev)
1057 		d = d->next;
1058 	if (!d)
1059 		goto drop_unlock;  /* should never happen */
1060 
1061 	/* Is it a reply to our BOOTP request? */
1062 	if (b->op != BOOTP_REPLY ||
1063 	    b->xid != d->xid) {
1064 		net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1065 				    d->dev->name, b->op, b->xid);
1066 		goto drop_unlock;
1067 	}
1068 
1069 	/* Parse extensions */
1070 	if (ext_len >= 4 &&
1071 	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1072 		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1073 		u8 *ext;
1074 
1075 #ifdef IPCONFIG_DHCP
1076 		if (ic_proto_enabled & IC_USE_DHCP) {
1077 			__be32 server_id = NONE;
1078 			int mt = 0;
1079 
1080 			ext = &b->exten[4];
1081 			while (ext < end && *ext != 0xff) {
1082 				u8 *opt = ext++;
1083 				if (*opt == 0)	/* Padding */
1084 					continue;
1085 				ext += *ext + 1;
1086 				if (ext >= end)
1087 					break;
1088 				switch (*opt) {
1089 				case 53:	/* Message type */
1090 					if (opt[1])
1091 						mt = opt[2];
1092 					break;
1093 				case 54:	/* Server ID (IP address) */
1094 					if (opt[1] >= 4)
1095 						memcpy(&server_id, opt + 2, 4);
1096 					break;
1097 				}
1098 			}
1099 
1100 			pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1101 
1102 			switch (mt) {
1103 			case DHCPOFFER:
1104 				/* While in the process of accepting one offer,
1105 				 * ignore all others.
1106 				 */
1107 				if (ic_myaddr != NONE)
1108 					goto drop_unlock;
1109 
1110 				/* Let's accept that offer. */
1111 				ic_myaddr = b->your_ip;
1112 				ic_servaddr = server_id;
1113 				pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1114 					 &ic_myaddr, &b->iph.saddr);
1115 				/* The DHCP indicated server address takes
1116 				 * precedence over the bootp header one if
1117 				 * they are different.
1118 				 */
1119 				if ((server_id != NONE) &&
1120 				    (b->server_ip != server_id))
1121 					b->server_ip = ic_servaddr;
1122 				break;
1123 
1124 			case DHCPACK:
1125 				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1126 					goto drop_unlock;
1127 
1128 				/* Yeah! */
1129 				break;
1130 
1131 			default:
1132 				/* Urque.  Forget it*/
1133 				ic_myaddr = NONE;
1134 				ic_servaddr = NONE;
1135 				goto drop_unlock;
1136 			}
1137 
1138 			ic_dhcp_msgtype = mt;
1139 
1140 		}
1141 #endif /* IPCONFIG_DHCP */
1142 
1143 		ext = &b->exten[4];
1144 		while (ext < end && *ext != 0xff) {
1145 			u8 *opt = ext++;
1146 			if (*opt == 0)	/* Padding */
1147 				continue;
1148 			ext += *ext + 1;
1149 			if (ext < end)
1150 				ic_do_bootp_ext(opt);
1151 		}
1152 	}
1153 
1154 	/* We have a winner! */
1155 	ic_dev = d;
1156 	ic_myaddr = b->your_ip;
1157 	ic_servaddr = b->server_ip;
1158 	ic_addrservaddr = b->iph.saddr;
1159 	if (ic_gateway == NONE && b->relay_ip)
1160 		ic_gateway = b->relay_ip;
1161 	if (ic_nameservers[0] == NONE)
1162 		ic_nameservers[0] = ic_servaddr;
1163 	ic_got_reply = IC_BOOTP;
1164 
1165 drop_unlock:
1166 	/* Show's over.  Nothing to see here.  */
1167 	spin_unlock(&ic_recv_lock);
1168 
1169 drop:
1170 	/* Throw the packet out. */
1171 	kfree_skb(skb);
1172 
1173 	return 0;
1174 }
1175 
1176 
1177 #endif
1178 
1179 
1180 /*
1181  *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
1182  */
1183 
1184 #ifdef IPCONFIG_DYNAMIC
1185 
1186 static int __init ic_dynamic(void)
1187 {
1188 	int retries;
1189 	struct ic_device *d;
1190 	unsigned long start_jiffies, timeout, jiff;
1191 	int do_bootp = ic_proto_have_if & IC_BOOTP;
1192 	int do_rarp = ic_proto_have_if & IC_RARP;
1193 
1194 	/*
1195 	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1196 	 * This routine gets only called when some pieces of information
1197 	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1198 	 */
1199 	if (!ic_proto_enabled) {
1200 		pr_err("IP-Config: Incomplete network configuration information\n");
1201 		return -1;
1202 	}
1203 
1204 #ifdef IPCONFIG_BOOTP
1205 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1206 		pr_err("DHCP/BOOTP: No suitable device found\n");
1207 #endif
1208 #ifdef IPCONFIG_RARP
1209 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1210 		pr_err("RARP: No suitable device found\n");
1211 #endif
1212 
1213 	if (!ic_proto_have_if)
1214 		/* Error message already printed */
1215 		return -1;
1216 
1217 	/*
1218 	 * Setup protocols
1219 	 */
1220 #ifdef IPCONFIG_BOOTP
1221 	if (do_bootp)
1222 		ic_bootp_init();
1223 #endif
1224 #ifdef IPCONFIG_RARP
1225 	if (do_rarp)
1226 		ic_rarp_init();
1227 #endif
1228 
1229 	/*
1230 	 * Send requests and wait, until we get an answer. This loop
1231 	 * seems to be a terrible waste of CPU time, but actually there is
1232 	 * only one process running at all, so we don't need to use any
1233 	 * scheduler functions.
1234 	 * [Actually we could now, but the nothing else running note still
1235 	 *  applies.. - AC]
1236 	 */
1237 	pr_notice("Sending %s%s%s requests .",
1238 		  do_bootp
1239 		  ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1240 		  (do_bootp && do_rarp) ? " and " : "",
1241 		  do_rarp ? "RARP" : "");
1242 
1243 	start_jiffies = jiffies;
1244 	d = ic_first_dev;
1245 	retries = CONF_SEND_RETRIES;
1246 	get_random_bytes(&timeout, sizeof(timeout));
1247 	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1248 	for (;;) {
1249 #ifdef IPCONFIG_BOOTP
1250 		if (do_bootp && (d->able & IC_BOOTP))
1251 			ic_bootp_send_if(d, jiffies - start_jiffies);
1252 #endif
1253 #ifdef IPCONFIG_RARP
1254 		if (do_rarp && (d->able & IC_RARP))
1255 			ic_rarp_send_if(d);
1256 #endif
1257 
1258 		if (!d->next) {
1259 			jiff = jiffies + timeout;
1260 			while (time_before(jiffies, jiff) && !ic_got_reply)
1261 				schedule_timeout_uninterruptible(1);
1262 		}
1263 #ifdef IPCONFIG_DHCP
1264 		/* DHCP isn't done until we get a DHCPACK. */
1265 		if ((ic_got_reply & IC_BOOTP) &&
1266 		    (ic_proto_enabled & IC_USE_DHCP) &&
1267 		    ic_dhcp_msgtype != DHCPACK) {
1268 			ic_got_reply = 0;
1269 			/* continue on device that got the reply */
1270 			d = ic_dev;
1271 			pr_cont(",");
1272 			continue;
1273 		}
1274 #endif /* IPCONFIG_DHCP */
1275 
1276 		if (ic_got_reply) {
1277 			pr_cont(" OK\n");
1278 			break;
1279 		}
1280 
1281 		if ((d = d->next))
1282 			continue;
1283 
1284 		if (! --retries) {
1285 			pr_cont(" timed out!\n");
1286 			break;
1287 		}
1288 
1289 		d = ic_first_dev;
1290 
1291 		timeout = timeout CONF_TIMEOUT_MULT;
1292 		if (timeout > CONF_TIMEOUT_MAX)
1293 			timeout = CONF_TIMEOUT_MAX;
1294 
1295 		pr_cont(".");
1296 	}
1297 
1298 #ifdef IPCONFIG_BOOTP
1299 	if (do_bootp)
1300 		ic_bootp_cleanup();
1301 #endif
1302 #ifdef IPCONFIG_RARP
1303 	if (do_rarp)
1304 		ic_rarp_cleanup();
1305 #endif
1306 
1307 	if (!ic_got_reply) {
1308 		ic_myaddr = NONE;
1309 		return -1;
1310 	}
1311 
1312 	pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1313 		((ic_got_reply & IC_RARP) ? "RARP"
1314 		: (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1315 		&ic_addrservaddr, &ic_myaddr);
1316 
1317 	return 0;
1318 }
1319 
1320 #endif /* IPCONFIG_DYNAMIC */
1321 
1322 #ifdef CONFIG_PROC_FS
1323 /* proc_dir_entry for /proc/net/ipconfig */
1324 static struct proc_dir_entry *ipconfig_dir;
1325 
1326 /* Name servers: */
1327 static int pnp_seq_show(struct seq_file *seq, void *v)
1328 {
1329 	int i;
1330 
1331 	if (ic_proto_used & IC_PROTO)
1332 		seq_printf(seq, "#PROTO: %s\n",
1333 			   (ic_proto_used & IC_RARP) ? "RARP"
1334 			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1335 	else
1336 		seq_puts(seq, "#MANUAL\n");
1337 
1338 	if (ic_domain[0])
1339 		seq_printf(seq,
1340 			   "domain %s\n", ic_domain);
1341 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1342 		if (ic_nameservers[i] != NONE)
1343 			seq_printf(seq, "nameserver %pI4\n",
1344 				   &ic_nameservers[i]);
1345 	}
1346 	if (ic_servaddr != NONE)
1347 		seq_printf(seq, "bootserver %pI4\n",
1348 			   &ic_servaddr);
1349 	return 0;
1350 }
1351 
1352 /* Create the /proc/net/ipconfig directory */
1353 static int __init ipconfig_proc_net_init(void)
1354 {
1355 	ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net);
1356 	if (!ipconfig_dir)
1357 		return -ENOMEM;
1358 
1359 	return 0;
1360 }
1361 
1362 /* Create a new file under /proc/net/ipconfig */
1363 static int ipconfig_proc_net_create(const char *name,
1364 				    const struct proc_ops *proc_ops)
1365 {
1366 	char *pname;
1367 	struct proc_dir_entry *p;
1368 
1369 	if (!ipconfig_dir)
1370 		return -ENOMEM;
1371 
1372 	pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name);
1373 	if (!pname)
1374 		return -ENOMEM;
1375 
1376 	p = proc_create(pname, 0444, init_net.proc_net, proc_ops);
1377 	kfree(pname);
1378 	if (!p)
1379 		return -ENOMEM;
1380 
1381 	return 0;
1382 }
1383 
1384 /* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */
1385 static int ntp_servers_show(struct seq_file *seq, void *v)
1386 {
1387 	int i;
1388 
1389 	for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1390 		if (ic_ntp_servers[i] != NONE)
1391 			seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]);
1392 	}
1393 	return 0;
1394 }
1395 DEFINE_PROC_SHOW_ATTRIBUTE(ntp_servers);
1396 #endif /* CONFIG_PROC_FS */
1397 
1398 /*
1399  *  Extract IP address from the parameter string if needed. Note that we
1400  *  need to have root_server_addr set _before_ IPConfig gets called as it
1401  *  can override it.
1402  */
1403 __be32 __init root_nfs_parse_addr(char *name)
1404 {
1405 	__be32 addr;
1406 	int octets = 0;
1407 	char *cp, *cq;
1408 
1409 	cp = cq = name;
1410 	while (octets < 4) {
1411 		while (*cp >= '0' && *cp <= '9')
1412 			cp++;
1413 		if (cp == cq || cp - cq > 3)
1414 			break;
1415 		if (*cp == '.' || octets == 3)
1416 			octets++;
1417 		if (octets < 4)
1418 			cp++;
1419 		cq = cp;
1420 	}
1421 	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1422 		if (*cp == ':')
1423 			*cp++ = '\0';
1424 		addr = in_aton(name);
1425 		memmove(name, cp, strlen(cp) + 1);
1426 	} else
1427 		addr = NONE;
1428 
1429 	return addr;
1430 }
1431 
1432 #define DEVICE_WAIT_MAX		12 /* 12 seconds */
1433 
1434 static int __init wait_for_devices(void)
1435 {
1436 	int i;
1437 	bool try_init_devs = true;
1438 
1439 	for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1440 		struct net_device *dev;
1441 		int found = 0;
1442 
1443 		/* make sure deferred device probes are finished */
1444 		wait_for_device_probe();
1445 
1446 		rtnl_lock();
1447 		for_each_netdev(&init_net, dev) {
1448 			if (ic_is_init_dev(dev)) {
1449 				found = 1;
1450 				break;
1451 			}
1452 		}
1453 		rtnl_unlock();
1454 		if (found)
1455 			return 0;
1456 		if (try_init_devs &&
1457 		    (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) {
1458 			try_init_devs = false;
1459 			wait_for_init_devices_probe();
1460 		}
1461 		ssleep(1);
1462 	}
1463 	return -ENODEV;
1464 }
1465 
1466 /*
1467  *	IP Autoconfig dispatcher.
1468  */
1469 
1470 static int __init ip_auto_config(void)
1471 {
1472 	__be32 addr;
1473 #ifdef IPCONFIG_DYNAMIC
1474 	int retries = CONF_OPEN_RETRIES;
1475 #endif
1476 	int err;
1477 	unsigned int i, count;
1478 
1479 	/* Initialise all name servers and NTP servers to NONE (but only if the
1480 	 * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded,
1481 	 * otherwise we'll overwrite the IP addresses specified there)
1482 	 */
1483 	if (ic_set_manually == 0) {
1484 		ic_nameservers_predef();
1485 		ic_ntp_servers_predef();
1486 	}
1487 
1488 #ifdef CONFIG_PROC_FS
1489 	proc_create_single("pnp", 0444, init_net.proc_net, pnp_seq_show);
1490 
1491 	if (ipconfig_proc_net_init() == 0)
1492 		ipconfig_proc_net_create("ntp_servers", &ntp_servers_proc_ops);
1493 #endif /* CONFIG_PROC_FS */
1494 
1495 	if (!ic_enable)
1496 		return 0;
1497 
1498 	pr_debug("IP-Config: Entered.\n");
1499 #ifdef IPCONFIG_DYNAMIC
1500  try_try_again:
1501 #endif
1502 	/* Wait for devices to appear */
1503 	err = wait_for_devices();
1504 	if (err)
1505 		return err;
1506 
1507 	/* Setup all network devices */
1508 	err = ic_open_devs();
1509 	if (err)
1510 		return err;
1511 
1512 	/* Give drivers a chance to settle */
1513 	msleep(CONF_POST_OPEN);
1514 
1515 	/*
1516 	 * If the config information is insufficient (e.g., our IP address or
1517 	 * IP address of the boot server is missing or we have multiple network
1518 	 * interfaces and no default was set), use BOOTP or RARP to get the
1519 	 * missing values.
1520 	 */
1521 	if (ic_myaddr == NONE ||
1522 #if defined(CONFIG_ROOT_NFS) || defined(CONFIG_CIFS_ROOT)
1523 	    (root_server_addr == NONE &&
1524 	     ic_servaddr == NONE &&
1525 	     (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) ||
1526 #endif
1527 	    ic_first_dev->next) {
1528 #ifdef IPCONFIG_DYNAMIC
1529 		if (ic_dynamic() < 0) {
1530 			ic_close_devs();
1531 
1532 			/*
1533 			 * I don't know why, but sometimes the
1534 			 * eepro100 driver (at least) gets upset and
1535 			 * doesn't work the first time it's opened.
1536 			 * But then if you close it and reopen it, it
1537 			 * works just fine.  So we need to try that at
1538 			 * least once before giving up.
1539 			 *
1540 			 * Also, if the root will be NFS-mounted, we
1541 			 * have nowhere to go if DHCP fails.  So we
1542 			 * just have to keep trying forever.
1543 			 *
1544 			 * 				-- Chip
1545 			 */
1546 #ifdef CONFIG_ROOT_NFS
1547 			if (ROOT_DEV ==  Root_NFS) {
1548 				pr_err("IP-Config: Retrying forever (NFS root)...\n");
1549 				goto try_try_again;
1550 			}
1551 #endif
1552 #ifdef CONFIG_CIFS_ROOT
1553 			if (ROOT_DEV == Root_CIFS) {
1554 				pr_err("IP-Config: Retrying forever (CIFS root)...\n");
1555 				goto try_try_again;
1556 			}
1557 #endif
1558 
1559 			if (--retries) {
1560 				pr_err("IP-Config: Reopening network devices...\n");
1561 				goto try_try_again;
1562 			}
1563 
1564 			/* Oh, well.  At least we tried. */
1565 			pr_err("IP-Config: Auto-configuration of network failed\n");
1566 			return -1;
1567 		}
1568 #else /* !DYNAMIC */
1569 		pr_err("IP-Config: Incomplete network configuration information\n");
1570 		ic_close_devs();
1571 		return -1;
1572 #endif /* IPCONFIG_DYNAMIC */
1573 	} else {
1574 		/* Device selected manually or only one device -> use it */
1575 		ic_dev = ic_first_dev;
1576 	}
1577 
1578 	addr = root_nfs_parse_addr(root_server_path);
1579 	if (root_server_addr == NONE)
1580 		root_server_addr = addr;
1581 
1582 	/*
1583 	 * Use defaults wherever applicable.
1584 	 */
1585 	if (ic_defaults() < 0)
1586 		return -1;
1587 
1588 	/*
1589 	 * Record which protocol was actually used.
1590 	 */
1591 #ifdef IPCONFIG_DYNAMIC
1592 	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1593 #endif
1594 
1595 #ifndef IPCONFIG_SILENT
1596 	/*
1597 	 * Clue in the operator.
1598 	 */
1599 	pr_info("IP-Config: Complete:\n");
1600 
1601 	pr_info("     device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1602 		ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1603 		&ic_myaddr, &ic_netmask, &ic_gateway);
1604 	pr_info("     host=%s, domain=%s, nis-domain=%s\n",
1605 		utsname()->nodename, ic_domain, utsname()->domainname);
1606 	pr_info("     bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1607 		&ic_servaddr, &root_server_addr, root_server_path);
1608 	if (ic_dev_mtu)
1609 		pr_cont(", mtu=%d", ic_dev_mtu);
1610 	/* Name servers (if any): */
1611 	for (i = 0, count = 0; i < CONF_NAMESERVERS_MAX; i++) {
1612 		if (ic_nameservers[i] != NONE) {
1613 			if (i == 0)
1614 				pr_info("     nameserver%u=%pI4",
1615 					i, &ic_nameservers[i]);
1616 			else
1617 				pr_cont(", nameserver%u=%pI4",
1618 					i, &ic_nameservers[i]);
1619 
1620 			count++;
1621 		}
1622 		if ((i + 1 == CONF_NAMESERVERS_MAX) && count > 0)
1623 			pr_cont("\n");
1624 	}
1625 	/* NTP servers (if any): */
1626 	for (i = 0, count = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1627 		if (ic_ntp_servers[i] != NONE) {
1628 			if (i == 0)
1629 				pr_info("     ntpserver%u=%pI4",
1630 					i, &ic_ntp_servers[i]);
1631 			else
1632 				pr_cont(", ntpserver%u=%pI4",
1633 					i, &ic_ntp_servers[i]);
1634 
1635 			count++;
1636 		}
1637 		if ((i + 1 == CONF_NTP_SERVERS_MAX) && count > 0)
1638 			pr_cont("\n");
1639 	}
1640 #endif /* !SILENT */
1641 
1642 	/*
1643 	 * Close all network devices except the device we've
1644 	 * autoconfigured and set up routes.
1645 	 */
1646 	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1647 		err = -1;
1648 	else
1649 		err = 0;
1650 
1651 	ic_close_devs();
1652 
1653 	return err;
1654 }
1655 
1656 late_initcall(ip_auto_config);
1657 
1658 
1659 /*
1660  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1661  *  command line parameter.  See Documentation/admin-guide/nfs/nfsroot.rst.
1662  */
1663 static int __init ic_proto_name(char *name)
1664 {
1665 	if (!strcmp(name, "on") || !strcmp(name, "any")) {
1666 		return 1;
1667 	}
1668 	if (!strcmp(name, "off") || !strcmp(name, "none")) {
1669 		return 0;
1670 	}
1671 #ifdef CONFIG_IP_PNP_DHCP
1672 	else if (!strncmp(name, "dhcp", 4)) {
1673 		char *client_id;
1674 
1675 		ic_proto_enabled &= ~IC_RARP;
1676 		client_id = strstr(name, "dhcp,");
1677 		if (client_id) {
1678 			char *v;
1679 
1680 			client_id = client_id + 5;
1681 			v = strchr(client_id, ',');
1682 			if (!v)
1683 				return 1;
1684 			*v = 0;
1685 			if (kstrtou8(client_id, 0, dhcp_client_identifier))
1686 				pr_debug("DHCP: Invalid client identifier type\n");
1687 			strncpy(dhcp_client_identifier + 1, v + 1, 251);
1688 			*v = ',';
1689 		}
1690 		return 1;
1691 	}
1692 #endif
1693 #ifdef CONFIG_IP_PNP_BOOTP
1694 	else if (!strcmp(name, "bootp")) {
1695 		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1696 		return 1;
1697 	}
1698 #endif
1699 #ifdef CONFIG_IP_PNP_RARP
1700 	else if (!strcmp(name, "rarp")) {
1701 		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1702 		return 1;
1703 	}
1704 #endif
1705 #ifdef IPCONFIG_DYNAMIC
1706 	else if (!strcmp(name, "both")) {
1707 		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1708 		return 1;
1709 	}
1710 #endif
1711 	return 0;
1712 }
1713 
1714 static int __init ip_auto_config_setup(char *addrs)
1715 {
1716 	char *cp, *ip, *dp;
1717 	int num = 0;
1718 
1719 	ic_set_manually = 1;
1720 	ic_enable = 1;
1721 
1722 	/*
1723 	 * If any dhcp, bootp etc options are set, leave autoconfig on
1724 	 * and skip the below static IP processing.
1725 	 */
1726 	if (ic_proto_name(addrs))
1727 		return 1;
1728 
1729 	/* If no static IP is given, turn off autoconfig and bail.  */
1730 	if (*addrs == 0 ||
1731 	    strcmp(addrs, "off") == 0 ||
1732 	    strcmp(addrs, "none") == 0) {
1733 		ic_enable = 0;
1734 		return 1;
1735 	}
1736 
1737 	/* Initialise all name servers and NTP servers to NONE */
1738 	ic_nameservers_predef();
1739 	ic_ntp_servers_predef();
1740 
1741 	/* Parse string for static IP assignment.  */
1742 	ip = addrs;
1743 	while (ip && *ip) {
1744 		if ((cp = strchr(ip, ':')))
1745 			*cp++ = '\0';
1746 		if (strlen(ip) > 0) {
1747 			pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1748 			switch (num) {
1749 			case 0:
1750 				if ((ic_myaddr = in_aton(ip)) == ANY)
1751 					ic_myaddr = NONE;
1752 				break;
1753 			case 1:
1754 				if ((ic_servaddr = in_aton(ip)) == ANY)
1755 					ic_servaddr = NONE;
1756 				break;
1757 			case 2:
1758 				if ((ic_gateway = in_aton(ip)) == ANY)
1759 					ic_gateway = NONE;
1760 				break;
1761 			case 3:
1762 				if ((ic_netmask = in_aton(ip)) == ANY)
1763 					ic_netmask = NONE;
1764 				break;
1765 			case 4:
1766 				if ((dp = strchr(ip, '.'))) {
1767 					*dp++ = '\0';
1768 					strscpy(utsname()->domainname, dp,
1769 						sizeof(utsname()->domainname));
1770 				}
1771 				strscpy(utsname()->nodename, ip,
1772 					sizeof(utsname()->nodename));
1773 				ic_host_name_set = 1;
1774 				break;
1775 			case 5:
1776 				strscpy(user_dev_name, ip, sizeof(user_dev_name));
1777 				break;
1778 			case 6:
1779 				if (ic_proto_name(ip) == 0 &&
1780 				    ic_myaddr == NONE) {
1781 					ic_enable = 0;
1782 				}
1783 				break;
1784 			case 7:
1785 				if (CONF_NAMESERVERS_MAX >= 1) {
1786 					ic_nameservers[0] = in_aton(ip);
1787 					if (ic_nameservers[0] == ANY)
1788 						ic_nameservers[0] = NONE;
1789 				}
1790 				break;
1791 			case 8:
1792 				if (CONF_NAMESERVERS_MAX >= 2) {
1793 					ic_nameservers[1] = in_aton(ip);
1794 					if (ic_nameservers[1] == ANY)
1795 						ic_nameservers[1] = NONE;
1796 				}
1797 				break;
1798 			case 9:
1799 				if (CONF_NTP_SERVERS_MAX >= 1) {
1800 					ic_ntp_servers[0] = in_aton(ip);
1801 					if (ic_ntp_servers[0] == ANY)
1802 						ic_ntp_servers[0] = NONE;
1803 				}
1804 				break;
1805 			}
1806 		}
1807 		ip = cp;
1808 		num++;
1809 	}
1810 
1811 	return 1;
1812 }
1813 __setup("ip=", ip_auto_config_setup);
1814 
1815 static int __init nfsaddrs_config_setup(char *addrs)
1816 {
1817 	return ip_auto_config_setup(addrs);
1818 }
1819 __setup("nfsaddrs=", nfsaddrs_config_setup);
1820 
1821 static int __init vendor_class_identifier_setup(char *addrs)
1822 {
1823 	if (strscpy(vendor_class_identifier, addrs,
1824 		    sizeof(vendor_class_identifier))
1825 	    >= sizeof(vendor_class_identifier))
1826 		pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1827 			vendor_class_identifier);
1828 	return 1;
1829 }
1830 __setup("dhcpclass=", vendor_class_identifier_setup);
1831 
1832 static int __init set_carrier_timeout(char *str)
1833 {
1834 	ssize_t ret;
1835 
1836 	if (!str)
1837 		return 0;
1838 
1839 	ret = kstrtouint(str, 0, &carrier_timeout);
1840 	if (ret)
1841 		return 0;
1842 
1843 	return 1;
1844 }
1845 __setup("carrier_timeout=", set_carrier_timeout);
1846