xref: /linux/net/ipv4/ipconfig.c (revision e405b3c9d4aaa10972525fe2ea5cf94224020561)
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 + secs_to_jiffies(20);
278 	while (time_before(jiffies, start +
279 			   secs_to_jiffies(carrier_timeout))) {
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 + secs_to_jiffies(20);
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 /* DHCPACK can overwrite DNS if fallback was set upon first BOOTP reply */
669 static int ic_nameservers_fallback __initdata;
670 
671 /*
672  *  Initialize DHCP/BOOTP extension fields in the request.
673  */
674 
675 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
676 
677 #ifdef IPCONFIG_DHCP
678 
679 static void __init
680 ic_dhcp_init_options(u8 *options, struct ic_device *d)
681 {
682 	static const u8 ic_req_params[] = {
683 		1,	/* Subnet mask */
684 		3,	/* Default gateway */
685 		6,	/* DNS server */
686 		12,	/* Host name */
687 		15,	/* Domain name */
688 		17,	/* Boot path */
689 		26,	/* MTU */
690 		40,	/* NIS domain name */
691 		42,	/* NTP servers */
692 	};
693 	u8 mt = (ic_servaddr == NONE) ? DHCPDISCOVER : DHCPREQUEST;
694 	u8 *e = options;
695 	int len;
696 
697 	pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
698 
699 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
700 	e += 4;
701 
702 	*e++ = 53;		/* DHCP message type */
703 	*e++ = 1;
704 	*e++ = mt;
705 
706 	if (mt == DHCPREQUEST) {
707 		*e++ = 54;	/* Server ID (IP address) */
708 		*e++ = 4;
709 		memcpy(e, &ic_servaddr, 4);
710 		e += 4;
711 
712 		*e++ = 50;	/* Requested IP address */
713 		*e++ = 4;
714 		memcpy(e, &ic_myaddr, 4);
715 		e += 4;
716 	}
717 
718 	*e++ = 55;	/* Parameter request list */
719 	*e++ = sizeof(ic_req_params);
720 	memcpy(e, ic_req_params, sizeof(ic_req_params));
721 	e += sizeof(ic_req_params);
722 
723 	if (ic_host_name_set) {
724 		*e++ = 12;	/* host-name */
725 		len = strlen(utsname()->nodename);
726 		*e++ = len;
727 		memcpy(e, utsname()->nodename, len);
728 		e += len;
729 	}
730 	if (*vendor_class_identifier) {
731 		pr_info("DHCP: sending class identifier \"%s\"\n",
732 			vendor_class_identifier);
733 		*e++ = 60;	/* Class-identifier */
734 		len = strlen(vendor_class_identifier);
735 		*e++ = len;
736 		memcpy(e, vendor_class_identifier, len);
737 		e += len;
738 	}
739 	len = strlen(dhcp_client_identifier + 1);
740 	/* the minimum length of identifier is 2, include 1 byte type,
741 	 * and can not be larger than the length of options
742 	 */
743 	if (len >= 1 && len < 312 - (e - options) - 1) {
744 		*e++ = 61;
745 		*e++ = len + 1;
746 		memcpy(e, dhcp_client_identifier, len + 1);
747 		e += len + 1;
748 	}
749 
750 	*e++ = 255;	/* End of the list */
751 }
752 
753 #endif /* IPCONFIG_DHCP */
754 
755 static void __init ic_bootp_init_ext(u8 *e)
756 {
757 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
758 	e += 4;
759 	*e++ = 1;		/* Subnet mask request */
760 	*e++ = 4;
761 	e += 4;
762 	*e++ = 3;		/* Default gateway request */
763 	*e++ = 4;
764 	e += 4;
765 #if CONF_NAMESERVERS_MAX > 0
766 	*e++ = 6;		/* (DNS) name server request */
767 	*e++ = 4 * CONF_NAMESERVERS_MAX;
768 	e += 4 * CONF_NAMESERVERS_MAX;
769 #endif
770 	*e++ = 12;		/* Host name request */
771 	*e++ = 32;
772 	e += 32;
773 	*e++ = 40;		/* NIS Domain name request */
774 	*e++ = 32;
775 	e += 32;
776 	*e++ = 17;		/* Boot path */
777 	*e++ = 40;
778 	e += 40;
779 
780 	*e++ = 57;		/* set extension buffer size for reply */
781 	*e++ = 2;
782 	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
783 	*e++ = 150;
784 
785 	*e++ = 255;		/* End of the list */
786 }
787 
788 
789 /*
790  *  Initialize the DHCP/BOOTP mechanism.
791  */
792 static inline void __init ic_bootp_init(void)
793 {
794 	/* Re-initialise all name servers and NTP servers to NONE, in case any
795 	 * were set via the "ip=" or "nfsaddrs=" kernel command line parameters:
796 	 * any IP addresses specified there will already have been decoded but
797 	 * are no longer needed
798 	 */
799 	ic_nameservers_predef();
800 	ic_ntp_servers_predef();
801 
802 	dev_add_pack(&bootp_packet_type);
803 }
804 
805 
806 /*
807  *  DHCP/BOOTP cleanup.
808  */
809 static inline void __init ic_bootp_cleanup(void)
810 {
811 	dev_remove_pack(&bootp_packet_type);
812 }
813 
814 
815 /*
816  *  Send DHCP/BOOTP request to single interface.
817  */
818 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
819 {
820 	struct net_device *dev = d->dev;
821 	struct sk_buff *skb;
822 	struct bootp_pkt *b;
823 	struct iphdr *h;
824 	int hlen = LL_RESERVED_SPACE(dev);
825 	int tlen = dev->needed_tailroom;
826 
827 	/* Allocate packet */
828 	skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
829 			GFP_KERNEL);
830 	if (!skb)
831 		return;
832 	skb_reserve(skb, hlen);
833 	b = skb_put_zero(skb, sizeof(struct bootp_pkt));
834 
835 	/* Construct IP header */
836 	skb_reset_network_header(skb);
837 	h = ip_hdr(skb);
838 	h->version = 4;
839 	h->ihl = 5;
840 	h->tot_len = htons(sizeof(struct bootp_pkt));
841 	h->frag_off = htons(IP_DF);
842 	h->ttl = 64;
843 	h->protocol = IPPROTO_UDP;
844 	h->daddr = htonl(INADDR_BROADCAST);
845 	h->check = ip_fast_csum((unsigned char *) h, h->ihl);
846 
847 	/* Construct UDP header */
848 	b->udph.source = htons(68);
849 	b->udph.dest = htons(67);
850 	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
851 	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
852 
853 	/* Construct DHCP/BOOTP header */
854 	b->op = BOOTP_REQUEST;
855 	if (dev->type < 256) /* check for false types */
856 		b->htype = dev->type;
857 	else if (dev->type == ARPHRD_FDDI)
858 		b->htype = ARPHRD_ETHER;
859 	else {
860 		pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
861 			dev->name);
862 		b->htype = dev->type; /* can cause undefined behavior */
863 	}
864 
865 	/* server_ip and your_ip address are both already zero per RFC2131 */
866 	b->hlen = dev->addr_len;
867 	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
868 	b->secs = htons(jiffies_diff / HZ);
869 	b->xid = d->xid;
870 
871 	/* add DHCP options or BOOTP extensions */
872 #ifdef IPCONFIG_DHCP
873 	if (ic_proto_enabled & IC_USE_DHCP)
874 		ic_dhcp_init_options(b->exten, d);
875 	else
876 #endif
877 		ic_bootp_init_ext(b->exten);
878 
879 	/* Chain packet down the line... */
880 	skb->dev = dev;
881 	skb->protocol = htons(ETH_P_IP);
882 	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
883 			    dev->broadcast, dev->dev_addr, skb->len) < 0) {
884 		kfree_skb(skb);
885 		printk("E");
886 		return;
887 	}
888 
889 	if (dev_queue_xmit(skb) < 0)
890 		printk("E");
891 }
892 
893 
894 /*
895  *  Copy BOOTP-supplied string
896  */
897 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
898 {
899 	if (!len)
900 		return 0;
901 	if (len > max-1)
902 		len = max-1;
903 	memcpy(dest, src, len);
904 	dest[len] = '\0';
905 	return 1;
906 }
907 
908 
909 /*
910  *  Process BOOTP extensions.
911  */
912 static void __init ic_do_bootp_ext(u8 *ext)
913 {
914 	u8 servers;
915 	int i;
916 	__be16 mtu;
917 
918 	u8 *c;
919 
920 	pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
921 	for (c=ext+2; c<ext+2+ext[1]; c++)
922 		pr_debug(" %02x", *c);
923 	pr_debug("\n");
924 
925 	switch (*ext++) {
926 	case 1:		/* Subnet mask */
927 		if (ic_netmask == NONE)
928 			memcpy(&ic_netmask, ext+1, 4);
929 		break;
930 	case 3:		/* Default gateway */
931 		if (ic_gateway == NONE)
932 			memcpy(&ic_gateway, ext+1, 4);
933 		break;
934 	case 6:		/* DNS server */
935 		servers= *ext/4;
936 		if (servers > CONF_NAMESERVERS_MAX)
937 			servers = CONF_NAMESERVERS_MAX;
938 		for (i = 0; i < servers; i++) {
939 			if (ic_nameservers[i] == NONE ||
940 			    ic_nameservers_fallback)
941 				memcpy(&ic_nameservers[i], ext+1+4*i, 4);
942 		}
943 		break;
944 	case 12:	/* Host name */
945 		if (!ic_host_name_set) {
946 			ic_bootp_string(utsname()->nodename, ext+1, *ext,
947 					__NEW_UTS_LEN);
948 			ic_host_name_set = 1;
949 		}
950 		break;
951 	case 15:	/* Domain name (DNS) */
952 		if (!ic_domain[0])
953 			ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
954 		break;
955 	case 17:	/* Root path */
956 		if (!root_server_path[0])
957 			ic_bootp_string(root_server_path, ext+1, *ext,
958 					sizeof(root_server_path));
959 		break;
960 	case 26:	/* Interface MTU */
961 		memcpy(&mtu, ext+1, sizeof(mtu));
962 		ic_dev_mtu = ntohs(mtu);
963 		break;
964 	case 40:	/* NIS Domain name (_not_ DNS) */
965 		ic_bootp_string(utsname()->domainname, ext+1, *ext,
966 				__NEW_UTS_LEN);
967 		break;
968 	case 42:	/* NTP servers */
969 		servers = *ext / 4;
970 		if (servers > CONF_NTP_SERVERS_MAX)
971 			servers = CONF_NTP_SERVERS_MAX;
972 		for (i = 0; i < servers; i++) {
973 			if (ic_ntp_servers[i] == NONE)
974 				memcpy(&ic_ntp_servers[i], ext+1+4*i, 4);
975 		}
976 		break;
977 	}
978 }
979 
980 
981 /*
982  *  Receive BOOTP reply.
983  */
984 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
985 {
986 	struct bootp_pkt *b;
987 	struct iphdr *h;
988 	struct ic_device *d;
989 	int len, ext_len;
990 
991 	if (!net_eq(dev_net(dev), &init_net))
992 		goto drop;
993 
994 	/* Perform verifications before taking the lock.  */
995 	if (skb->pkt_type == PACKET_OTHERHOST)
996 		goto drop;
997 
998 	skb = skb_share_check(skb, GFP_ATOMIC);
999 	if (!skb)
1000 		return NET_RX_DROP;
1001 
1002 	if (!pskb_may_pull(skb,
1003 			   sizeof(struct iphdr) +
1004 			   sizeof(struct udphdr)))
1005 		goto drop;
1006 
1007 	b = (struct bootp_pkt *)skb_network_header(skb);
1008 	h = &b->iph;
1009 
1010 	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
1011 		goto drop;
1012 
1013 	/* Fragments are not supported */
1014 	if (ip_is_fragment(h)) {
1015 		net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
1016 		goto drop;
1017 	}
1018 
1019 	if (skb->len < ntohs(h->tot_len))
1020 		goto drop;
1021 
1022 	if (ip_fast_csum((char *) h, h->ihl))
1023 		goto drop;
1024 
1025 	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
1026 		goto drop;
1027 
1028 	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
1029 		goto drop;
1030 
1031 	len = ntohs(b->udph.len) - sizeof(struct udphdr);
1032 	ext_len = len - (sizeof(*b) -
1033 			 sizeof(struct iphdr) -
1034 			 sizeof(struct udphdr) -
1035 			 sizeof(b->exten));
1036 	if (ext_len < 0)
1037 		goto drop;
1038 
1039 	/* Ok the front looks good, make sure we can get at the rest.  */
1040 	if (!pskb_may_pull(skb, skb->len))
1041 		goto drop;
1042 
1043 	b = (struct bootp_pkt *)skb_network_header(skb);
1044 	h = &b->iph;
1045 
1046 	/* One reply at a time, please. */
1047 	spin_lock(&ic_recv_lock);
1048 
1049 	/* If we already have a reply, just drop the packet */
1050 	if (ic_got_reply)
1051 		goto drop_unlock;
1052 
1053 	/* Find the ic_device that the packet arrived on */
1054 	d = ic_first_dev;
1055 	while (d && d->dev != dev)
1056 		d = d->next;
1057 	if (!d)
1058 		goto drop_unlock;  /* should never happen */
1059 
1060 	/* Is it a reply to our BOOTP request? */
1061 	if (b->op != BOOTP_REPLY ||
1062 	    b->xid != d->xid) {
1063 		net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1064 				    d->dev->name, b->op, b->xid);
1065 		goto drop_unlock;
1066 	}
1067 
1068 	/* Parse extensions */
1069 	if (ext_len >= 4 &&
1070 	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1071 		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1072 		u8 *ext;
1073 
1074 #ifdef IPCONFIG_DHCP
1075 		if (ic_proto_enabled & IC_USE_DHCP) {
1076 			__be32 server_id = NONE;
1077 			int mt = 0;
1078 
1079 			ext = &b->exten[4];
1080 			while (ext < end && *ext != 0xff) {
1081 				u8 *opt = ext++;
1082 				if (*opt == 0)	/* Padding */
1083 					continue;
1084 				ext += *ext + 1;
1085 				if (ext >= end)
1086 					break;
1087 				switch (*opt) {
1088 				case 53:	/* Message type */
1089 					if (opt[1])
1090 						mt = opt[2];
1091 					break;
1092 				case 54:	/* Server ID (IP address) */
1093 					if (opt[1] >= 4)
1094 						memcpy(&server_id, opt + 2, 4);
1095 					break;
1096 				}
1097 			}
1098 
1099 			pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1100 
1101 			switch (mt) {
1102 			case DHCPOFFER:
1103 				/* While in the process of accepting one offer,
1104 				 * ignore all others.
1105 				 */
1106 				if (ic_myaddr != NONE)
1107 					goto drop_unlock;
1108 
1109 				/* Let's accept that offer. */
1110 				ic_myaddr = b->your_ip;
1111 				ic_servaddr = server_id;
1112 				pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1113 					 &ic_myaddr, &b->iph.saddr);
1114 				/* The DHCP indicated server address takes
1115 				 * precedence over the bootp header one if
1116 				 * they are different.
1117 				 */
1118 				if ((server_id != NONE) &&
1119 				    (b->server_ip != server_id))
1120 					b->server_ip = ic_servaddr;
1121 				break;
1122 
1123 			case DHCPACK:
1124 				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1125 					goto drop_unlock;
1126 
1127 				/* Yeah! */
1128 				break;
1129 
1130 			default:
1131 				/* Urque.  Forget it*/
1132 				ic_myaddr = NONE;
1133 				ic_servaddr = NONE;
1134 				goto drop_unlock;
1135 			}
1136 
1137 			ic_dhcp_msgtype = mt;
1138 
1139 		}
1140 #endif /* IPCONFIG_DHCP */
1141 
1142 		ext = &b->exten[4];
1143 		while (ext < end && *ext != 0xff) {
1144 			u8 *opt = ext++;
1145 			if (*opt == 0)	/* Padding */
1146 				continue;
1147 			ext += *ext + 1;
1148 			if (ext < end)
1149 				ic_do_bootp_ext(opt);
1150 		}
1151 	}
1152 
1153 	/* We have a winner! */
1154 	ic_dev = d;
1155 	ic_myaddr = b->your_ip;
1156 	ic_servaddr = b->server_ip;
1157 	ic_addrservaddr = b->iph.saddr;
1158 	if (ic_gateway == NONE && b->relay_ip)
1159 		ic_gateway = b->relay_ip;
1160 	if (ic_nameservers[0] == NONE) {
1161 		ic_nameservers[0] = ic_servaddr;
1162 		ic_nameservers_fallback = 1;
1163 	}
1164 	ic_got_reply = IC_BOOTP;
1165 
1166 drop_unlock:
1167 	/* Show's over.  Nothing to see here.  */
1168 	spin_unlock(&ic_recv_lock);
1169 
1170 drop:
1171 	/* Throw the packet out. */
1172 	kfree_skb(skb);
1173 
1174 	return 0;
1175 }
1176 
1177 
1178 #endif
1179 
1180 
1181 /*
1182  *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
1183  */
1184 
1185 #ifdef IPCONFIG_DYNAMIC
1186 
1187 static int __init ic_dynamic(void)
1188 {
1189 	int retries;
1190 	struct ic_device *d;
1191 	unsigned long start_jiffies, timeout, jiff;
1192 	int do_bootp = ic_proto_have_if & IC_BOOTP;
1193 	int do_rarp = ic_proto_have_if & IC_RARP;
1194 
1195 	/*
1196 	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1197 	 * This routine gets only called when some pieces of information
1198 	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1199 	 */
1200 	if (!ic_proto_enabled) {
1201 		pr_err("IP-Config: Incomplete network configuration information\n");
1202 		return -1;
1203 	}
1204 
1205 #ifdef IPCONFIG_BOOTP
1206 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1207 		pr_err("DHCP/BOOTP: No suitable device found\n");
1208 #endif
1209 #ifdef IPCONFIG_RARP
1210 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1211 		pr_err("RARP: No suitable device found\n");
1212 #endif
1213 
1214 	if (!ic_proto_have_if)
1215 		/* Error message already printed */
1216 		return -1;
1217 
1218 	/*
1219 	 * Setup protocols
1220 	 */
1221 #ifdef IPCONFIG_BOOTP
1222 	if (do_bootp)
1223 		ic_bootp_init();
1224 #endif
1225 #ifdef IPCONFIG_RARP
1226 	if (do_rarp)
1227 		ic_rarp_init();
1228 #endif
1229 
1230 	/*
1231 	 * Send requests and wait, until we get an answer. This loop
1232 	 * seems to be a terrible waste of CPU time, but actually there is
1233 	 * only one process running at all, so we don't need to use any
1234 	 * scheduler functions.
1235 	 * [Actually we could now, but the nothing else running note still
1236 	 *  applies.. - AC]
1237 	 */
1238 	pr_notice("Sending %s%s%s requests .",
1239 		  do_bootp
1240 		  ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1241 		  (do_bootp && do_rarp) ? " and " : "",
1242 		  do_rarp ? "RARP" : "");
1243 
1244 	start_jiffies = jiffies;
1245 	d = ic_first_dev;
1246 	retries = CONF_SEND_RETRIES;
1247 	get_random_bytes(&timeout, sizeof(timeout));
1248 	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1249 	for (;;) {
1250 #ifdef IPCONFIG_BOOTP
1251 		if (do_bootp && (d->able & IC_BOOTP))
1252 			ic_bootp_send_if(d, jiffies - start_jiffies);
1253 #endif
1254 #ifdef IPCONFIG_RARP
1255 		if (do_rarp && (d->able & IC_RARP))
1256 			ic_rarp_send_if(d);
1257 #endif
1258 
1259 		if (!d->next) {
1260 			jiff = jiffies + timeout;
1261 			while (time_before(jiffies, jiff) && !ic_got_reply)
1262 				schedule_timeout_uninterruptible(1);
1263 		}
1264 #ifdef IPCONFIG_DHCP
1265 		/* DHCP isn't done until we get a DHCPACK. */
1266 		if ((ic_got_reply & IC_BOOTP) &&
1267 		    (ic_proto_enabled & IC_USE_DHCP) &&
1268 		    ic_dhcp_msgtype != DHCPACK) {
1269 			ic_got_reply = 0;
1270 			/* continue on device that got the reply */
1271 			d = ic_dev;
1272 			pr_cont(",");
1273 			continue;
1274 		}
1275 #endif /* IPCONFIG_DHCP */
1276 
1277 		if (ic_got_reply) {
1278 			pr_cont(" OK\n");
1279 			break;
1280 		}
1281 
1282 		if ((d = d->next))
1283 			continue;
1284 
1285 		if (! --retries) {
1286 			pr_cont(" timed out!\n");
1287 			break;
1288 		}
1289 
1290 		d = ic_first_dev;
1291 
1292 		timeout = timeout CONF_TIMEOUT_MULT;
1293 		if (timeout > CONF_TIMEOUT_MAX)
1294 			timeout = CONF_TIMEOUT_MAX;
1295 
1296 		pr_cont(".");
1297 	}
1298 
1299 #ifdef IPCONFIG_BOOTP
1300 	if (do_bootp)
1301 		ic_bootp_cleanup();
1302 #endif
1303 #ifdef IPCONFIG_RARP
1304 	if (do_rarp)
1305 		ic_rarp_cleanup();
1306 #endif
1307 
1308 	if (!ic_got_reply) {
1309 		ic_myaddr = NONE;
1310 		return -1;
1311 	}
1312 
1313 	pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1314 		((ic_got_reply & IC_RARP) ? "RARP"
1315 		: (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1316 		&ic_addrservaddr, &ic_myaddr);
1317 
1318 	return 0;
1319 }
1320 
1321 #endif /* IPCONFIG_DYNAMIC */
1322 
1323 #ifdef CONFIG_PROC_FS
1324 /* proc_dir_entry for /proc/net/ipconfig */
1325 static struct proc_dir_entry *ipconfig_dir;
1326 
1327 /* Name servers: */
1328 static int pnp_seq_show(struct seq_file *seq, void *v)
1329 {
1330 	int i;
1331 
1332 	if (ic_proto_used & IC_PROTO)
1333 		seq_printf(seq, "#PROTO: %s\n",
1334 			   (ic_proto_used & IC_RARP) ? "RARP"
1335 			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1336 	else
1337 		seq_puts(seq, "#MANUAL\n");
1338 
1339 	if (ic_domain[0])
1340 		seq_printf(seq,
1341 			   "domain %s\n", ic_domain);
1342 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1343 		if (ic_nameservers[i] != NONE)
1344 			seq_printf(seq, "nameserver %pI4\n",
1345 				   &ic_nameservers[i]);
1346 	}
1347 	if (ic_servaddr != NONE)
1348 		seq_printf(seq, "bootserver %pI4\n",
1349 			   &ic_servaddr);
1350 	return 0;
1351 }
1352 
1353 /* Create the /proc/net/ipconfig directory */
1354 static int __init ipconfig_proc_net_init(void)
1355 {
1356 	ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net);
1357 	if (!ipconfig_dir)
1358 		return -ENOMEM;
1359 
1360 	return 0;
1361 }
1362 
1363 /* Create a new file under /proc/net/ipconfig */
1364 static int ipconfig_proc_net_create(const char *name,
1365 				    const struct proc_ops *proc_ops)
1366 {
1367 	char *pname;
1368 	struct proc_dir_entry *p;
1369 
1370 	if (!ipconfig_dir)
1371 		return -ENOMEM;
1372 
1373 	pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name);
1374 	if (!pname)
1375 		return -ENOMEM;
1376 
1377 	p = proc_create(pname, 0444, init_net.proc_net, proc_ops);
1378 	kfree(pname);
1379 	if (!p)
1380 		return -ENOMEM;
1381 
1382 	return 0;
1383 }
1384 
1385 /* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */
1386 static int ntp_servers_show(struct seq_file *seq, void *v)
1387 {
1388 	int i;
1389 
1390 	for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1391 		if (ic_ntp_servers[i] != NONE)
1392 			seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]);
1393 	}
1394 	return 0;
1395 }
1396 DEFINE_PROC_SHOW_ATTRIBUTE(ntp_servers);
1397 #endif /* CONFIG_PROC_FS */
1398 
1399 /*
1400  *  Extract IP address from the parameter string if needed. Note that we
1401  *  need to have root_server_addr set _before_ IPConfig gets called as it
1402  *  can override it.
1403  */
1404 __be32 __init root_nfs_parse_addr(char *name)
1405 {
1406 	__be32 addr;
1407 	int octets = 0;
1408 	char *cp, *cq;
1409 
1410 	cp = cq = name;
1411 	while (octets < 4) {
1412 		while (*cp >= '0' && *cp <= '9')
1413 			cp++;
1414 		if (cp == cq || cp - cq > 3)
1415 			break;
1416 		if (*cp == '.' || octets == 3)
1417 			octets++;
1418 		if (octets < 4)
1419 			cp++;
1420 		cq = cp;
1421 	}
1422 	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1423 		if (*cp == ':')
1424 			*cp++ = '\0';
1425 		addr = in_aton(name);
1426 		memmove(name, cp, strlen(cp) + 1);
1427 	} else
1428 		addr = NONE;
1429 
1430 	return addr;
1431 }
1432 
1433 #define DEVICE_WAIT_MAX		12 /* 12 seconds */
1434 
1435 static int __init wait_for_devices(void)
1436 {
1437 	int i;
1438 	bool try_init_devs = true;
1439 
1440 	for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1441 		struct net_device *dev;
1442 		int found = 0;
1443 
1444 		/* make sure deferred device probes are finished */
1445 		wait_for_device_probe();
1446 
1447 		rtnl_lock();
1448 		for_each_netdev(&init_net, dev) {
1449 			if (ic_is_init_dev(dev)) {
1450 				found = 1;
1451 				break;
1452 			}
1453 		}
1454 		rtnl_unlock();
1455 		if (found)
1456 			return 0;
1457 		if (try_init_devs &&
1458 		    (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) {
1459 			try_init_devs = false;
1460 			wait_for_init_devices_probe();
1461 		}
1462 		ssleep(1);
1463 	}
1464 	return -ENODEV;
1465 }
1466 
1467 /*
1468  *	IP Autoconfig dispatcher.
1469  */
1470 
1471 static int __init ip_auto_config(void)
1472 {
1473 	__be32 addr;
1474 #ifdef IPCONFIG_DYNAMIC
1475 	int retries = CONF_OPEN_RETRIES;
1476 #endif
1477 	int err;
1478 	unsigned int i, count;
1479 
1480 	/* Initialise all name servers and NTP servers to NONE (but only if the
1481 	 * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded,
1482 	 * otherwise we'll overwrite the IP addresses specified there)
1483 	 */
1484 	if (ic_set_manually == 0) {
1485 		ic_nameservers_predef();
1486 		ic_ntp_servers_predef();
1487 	}
1488 
1489 #ifdef CONFIG_PROC_FS
1490 	proc_create_single("pnp", 0444, init_net.proc_net, pnp_seq_show);
1491 
1492 	if (ipconfig_proc_net_init() == 0)
1493 		ipconfig_proc_net_create("ntp_servers", &ntp_servers_proc_ops);
1494 #endif /* CONFIG_PROC_FS */
1495 
1496 	if (!ic_enable)
1497 		return 0;
1498 
1499 	pr_debug("IP-Config: Entered.\n");
1500 #ifdef IPCONFIG_DYNAMIC
1501  try_try_again:
1502 #endif
1503 	/* Wait for devices to appear */
1504 	err = wait_for_devices();
1505 	if (err)
1506 		return err;
1507 
1508 	/* Setup all network devices */
1509 	err = ic_open_devs();
1510 	if (err)
1511 		return err;
1512 
1513 	/* Give drivers a chance to settle */
1514 	msleep(CONF_POST_OPEN);
1515 
1516 	/*
1517 	 * If the config information is insufficient (e.g., our IP address or
1518 	 * IP address of the boot server is missing or we have multiple network
1519 	 * interfaces and no default was set), use BOOTP or RARP to get the
1520 	 * missing values.
1521 	 */
1522 	if (ic_myaddr == NONE ||
1523 #if defined(CONFIG_ROOT_NFS) || defined(CONFIG_CIFS_ROOT)
1524 	    (root_server_addr == NONE &&
1525 	     ic_servaddr == NONE &&
1526 	     (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) ||
1527 #endif
1528 	    ic_first_dev->next) {
1529 #ifdef IPCONFIG_DYNAMIC
1530 		if (ic_dynamic() < 0) {
1531 			ic_close_devs();
1532 
1533 			/*
1534 			 * I don't know why, but sometimes the
1535 			 * eepro100 driver (at least) gets upset and
1536 			 * doesn't work the first time it's opened.
1537 			 * But then if you close it and reopen it, it
1538 			 * works just fine.  So we need to try that at
1539 			 * least once before giving up.
1540 			 *
1541 			 * Also, if the root will be NFS-mounted, we
1542 			 * have nowhere to go if DHCP fails.  So we
1543 			 * just have to keep trying forever.
1544 			 *
1545 			 * 				-- Chip
1546 			 */
1547 #ifdef CONFIG_ROOT_NFS
1548 			if (ROOT_DEV ==  Root_NFS) {
1549 				pr_err("IP-Config: Retrying forever (NFS root)...\n");
1550 				goto try_try_again;
1551 			}
1552 #endif
1553 #ifdef CONFIG_CIFS_ROOT
1554 			if (ROOT_DEV == Root_CIFS) {
1555 				pr_err("IP-Config: Retrying forever (CIFS root)...\n");
1556 				goto try_try_again;
1557 			}
1558 #endif
1559 
1560 			if (--retries) {
1561 				pr_err("IP-Config: Reopening network devices...\n");
1562 				goto try_try_again;
1563 			}
1564 
1565 			/* Oh, well.  At least we tried. */
1566 			pr_err("IP-Config: Auto-configuration of network failed\n");
1567 			return -1;
1568 		}
1569 #else /* !DYNAMIC */
1570 		pr_err("IP-Config: Incomplete network configuration information\n");
1571 		ic_close_devs();
1572 		return -1;
1573 #endif /* IPCONFIG_DYNAMIC */
1574 	} else {
1575 		/* Device selected manually or only one device -> use it */
1576 		ic_dev = ic_first_dev;
1577 	}
1578 
1579 	addr = root_nfs_parse_addr(root_server_path);
1580 	if (root_server_addr == NONE)
1581 		root_server_addr = addr;
1582 
1583 	/*
1584 	 * Use defaults wherever applicable.
1585 	 */
1586 	if (ic_defaults() < 0)
1587 		return -1;
1588 
1589 	/*
1590 	 * Record which protocol was actually used.
1591 	 */
1592 #ifdef IPCONFIG_DYNAMIC
1593 	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1594 #endif
1595 
1596 #ifndef IPCONFIG_SILENT
1597 	/*
1598 	 * Clue in the operator.
1599 	 */
1600 	pr_info("IP-Config: Complete:\n");
1601 
1602 	pr_info("     device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1603 		ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1604 		&ic_myaddr, &ic_netmask, &ic_gateway);
1605 	pr_info("     host=%s, domain=%s, nis-domain=%s\n",
1606 		utsname()->nodename, ic_domain, utsname()->domainname);
1607 	pr_info("     bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1608 		&ic_servaddr, &root_server_addr, root_server_path);
1609 	if (ic_dev_mtu)
1610 		pr_cont(", mtu=%d", ic_dev_mtu);
1611 	/* Name servers (if any): */
1612 	for (i = 0, count = 0; i < CONF_NAMESERVERS_MAX; i++) {
1613 		if (ic_nameservers[i] != NONE) {
1614 			if (i == 0)
1615 				pr_info("     nameserver%u=%pI4",
1616 					i, &ic_nameservers[i]);
1617 			else
1618 				pr_cont(", nameserver%u=%pI4",
1619 					i, &ic_nameservers[i]);
1620 
1621 			count++;
1622 		}
1623 		if ((i + 1 == CONF_NAMESERVERS_MAX) && count > 0)
1624 			pr_cont("\n");
1625 	}
1626 	/* NTP servers (if any): */
1627 	for (i = 0, count = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1628 		if (ic_ntp_servers[i] != NONE) {
1629 			if (i == 0)
1630 				pr_info("     ntpserver%u=%pI4",
1631 					i, &ic_ntp_servers[i]);
1632 			else
1633 				pr_cont(", ntpserver%u=%pI4",
1634 					i, &ic_ntp_servers[i]);
1635 
1636 			count++;
1637 		}
1638 		if ((i + 1 == CONF_NTP_SERVERS_MAX) && count > 0)
1639 			pr_cont("\n");
1640 	}
1641 #endif /* !SILENT */
1642 
1643 	/*
1644 	 * Close all network devices except the device we've
1645 	 * autoconfigured and set up routes.
1646 	 */
1647 	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1648 		err = -1;
1649 	else
1650 		err = 0;
1651 
1652 	ic_close_devs();
1653 
1654 	return err;
1655 }
1656 
1657 late_initcall(ip_auto_config);
1658 
1659 
1660 /*
1661  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1662  *  command line parameter.  See Documentation/admin-guide/nfs/nfsroot.rst.
1663  */
1664 static int __init ic_proto_name(char *name)
1665 {
1666 	if (!strcmp(name, "on") || !strcmp(name, "any")) {
1667 		return 1;
1668 	}
1669 	if (!strcmp(name, "off") || !strcmp(name, "none")) {
1670 		return 0;
1671 	}
1672 #ifdef CONFIG_IP_PNP_DHCP
1673 	else if (!strncmp(name, "dhcp", 4)) {
1674 		char *client_id;
1675 
1676 		ic_proto_enabled &= ~IC_RARP;
1677 		client_id = strstr(name, "dhcp,");
1678 		if (client_id) {
1679 			char *v;
1680 
1681 			client_id = client_id + 5;
1682 			v = strchr(client_id, ',');
1683 			if (!v)
1684 				return 1;
1685 			*v = 0;
1686 			if (kstrtou8(client_id, 0, dhcp_client_identifier))
1687 				pr_debug("DHCP: Invalid client identifier type\n");
1688 			strscpy(dhcp_client_identifier + 1, v + 1,
1689 				sizeof(dhcp_client_identifier) - 1);
1690 			*v = ',';
1691 		}
1692 		return 1;
1693 	}
1694 #endif
1695 #ifdef CONFIG_IP_PNP_BOOTP
1696 	else if (!strcmp(name, "bootp")) {
1697 		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1698 		return 1;
1699 	}
1700 #endif
1701 #ifdef CONFIG_IP_PNP_RARP
1702 	else if (!strcmp(name, "rarp")) {
1703 		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1704 		return 1;
1705 	}
1706 #endif
1707 #ifdef IPCONFIG_DYNAMIC
1708 	else if (!strcmp(name, "both")) {
1709 		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1710 		return 1;
1711 	}
1712 #endif
1713 	return 0;
1714 }
1715 
1716 static int __init ip_auto_config_setup(char *addrs)
1717 {
1718 	char *cp, *ip, *dp;
1719 	int num = 0;
1720 
1721 	ic_set_manually = 1;
1722 	ic_enable = 1;
1723 
1724 	/*
1725 	 * If any dhcp, bootp etc options are set, leave autoconfig on
1726 	 * and skip the below static IP processing.
1727 	 */
1728 	if (ic_proto_name(addrs))
1729 		return 1;
1730 
1731 	/* If no static IP is given, turn off autoconfig and bail.  */
1732 	if (*addrs == 0 ||
1733 	    strcmp(addrs, "off") == 0 ||
1734 	    strcmp(addrs, "none") == 0) {
1735 		ic_enable = 0;
1736 		return 1;
1737 	}
1738 
1739 	/* Initialise all name servers and NTP servers to NONE */
1740 	ic_nameservers_predef();
1741 	ic_ntp_servers_predef();
1742 
1743 	/* Parse string for static IP assignment.  */
1744 	ip = addrs;
1745 	while (ip && *ip) {
1746 		if ((cp = strchr(ip, ':')))
1747 			*cp++ = '\0';
1748 		if (strlen(ip) > 0) {
1749 			pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1750 			switch (num) {
1751 			case 0:
1752 				if ((ic_myaddr = in_aton(ip)) == ANY)
1753 					ic_myaddr = NONE;
1754 				break;
1755 			case 1:
1756 				if ((ic_servaddr = in_aton(ip)) == ANY)
1757 					ic_servaddr = NONE;
1758 				break;
1759 			case 2:
1760 				if ((ic_gateway = in_aton(ip)) == ANY)
1761 					ic_gateway = NONE;
1762 				break;
1763 			case 3:
1764 				if ((ic_netmask = in_aton(ip)) == ANY)
1765 					ic_netmask = NONE;
1766 				break;
1767 			case 4:
1768 				if ((dp = strchr(ip, '.'))) {
1769 					*dp++ = '\0';
1770 					strscpy(utsname()->domainname, dp,
1771 						sizeof(utsname()->domainname));
1772 				}
1773 				strscpy(utsname()->nodename, ip,
1774 					sizeof(utsname()->nodename));
1775 				ic_host_name_set = 1;
1776 				break;
1777 			case 5:
1778 				strscpy(user_dev_name, ip, sizeof(user_dev_name));
1779 				break;
1780 			case 6:
1781 				if (ic_proto_name(ip) == 0 &&
1782 				    ic_myaddr == NONE) {
1783 					ic_enable = 0;
1784 				}
1785 				break;
1786 			case 7:
1787 				if (CONF_NAMESERVERS_MAX >= 1) {
1788 					ic_nameservers[0] = in_aton(ip);
1789 					if (ic_nameservers[0] == ANY)
1790 						ic_nameservers[0] = NONE;
1791 				}
1792 				break;
1793 			case 8:
1794 				if (CONF_NAMESERVERS_MAX >= 2) {
1795 					ic_nameservers[1] = in_aton(ip);
1796 					if (ic_nameservers[1] == ANY)
1797 						ic_nameservers[1] = NONE;
1798 				}
1799 				break;
1800 			case 9:
1801 				if (CONF_NTP_SERVERS_MAX >= 1) {
1802 					ic_ntp_servers[0] = in_aton(ip);
1803 					if (ic_ntp_servers[0] == ANY)
1804 						ic_ntp_servers[0] = NONE;
1805 				}
1806 				break;
1807 			}
1808 		}
1809 		ip = cp;
1810 		num++;
1811 	}
1812 
1813 	return 1;
1814 }
1815 __setup("ip=", ip_auto_config_setup);
1816 
1817 static int __init nfsaddrs_config_setup(char *addrs)
1818 {
1819 	return ip_auto_config_setup(addrs);
1820 }
1821 __setup("nfsaddrs=", nfsaddrs_config_setup);
1822 
1823 static int __init vendor_class_identifier_setup(char *addrs)
1824 {
1825 	if (strscpy(vendor_class_identifier, addrs,
1826 		    sizeof(vendor_class_identifier))
1827 	    >= sizeof(vendor_class_identifier))
1828 		pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1829 			vendor_class_identifier);
1830 	return 1;
1831 }
1832 __setup("dhcpclass=", vendor_class_identifier_setup);
1833 
1834 static int __init set_carrier_timeout(char *str)
1835 {
1836 	ssize_t ret;
1837 
1838 	if (!str)
1839 		return 0;
1840 
1841 	ret = kstrtouint(str, 0, &carrier_timeout);
1842 	if (ret)
1843 		return 0;
1844 
1845 	return 1;
1846 }
1847 __setup("carrier_timeout=", set_carrier_timeout);
1848