xref: /linux/net/ipv4/ipconfig.c (revision 0b8061c340b643e01da431dd60c75a41bb1d31ec)
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 
266 	/* no point in waiting if we could not bring up at least one device */
267 	if (!ic_first_dev)
268 		goto have_carrier;
269 
270 	/* wait for a carrier on at least one device */
271 	start = jiffies;
272 	next_msg = start + msecs_to_jiffies(20000);
273 	while (time_before(jiffies, start +
274 			   msecs_to_jiffies(carrier_timeout * 1000))) {
275 		int wait, elapsed;
276 
277 		for_each_netdev(&init_net, dev)
278 			if (ic_is_init_dev(dev) && netif_carrier_ok(dev))
279 				goto have_carrier;
280 
281 		msleep(1);
282 
283 		if (time_before(jiffies, next_msg))
284 			continue;
285 
286 		elapsed = jiffies_to_msecs(jiffies - start);
287 		wait = (carrier_timeout * 1000 - elapsed + 500) / 1000;
288 		pr_info("Waiting up to %d more seconds for network.\n", wait);
289 		next_msg = jiffies + msecs_to_jiffies(20000);
290 	}
291 have_carrier:
292 	rtnl_unlock();
293 
294 	*last = NULL;
295 
296 	if (!ic_first_dev) {
297 		if (user_dev_name[0])
298 			pr_err("IP-Config: Device `%s' not found\n",
299 			       user_dev_name);
300 		else
301 			pr_err("IP-Config: No network devices available\n");
302 		return -ENODEV;
303 	}
304 	return 0;
305 }
306 
307 /* Close all network interfaces except the one we've autoconfigured, and its
308  * lowers, in case it's a stacked virtual interface.
309  */
310 static void __init ic_close_devs(void)
311 {
312 	struct net_device *selected_dev = ic_dev->dev;
313 	struct ic_device *d, *next;
314 	struct net_device *dev;
315 
316 	rtnl_lock();
317 	next = ic_first_dev;
318 	while ((d = next)) {
319 		bool bring_down = (d != ic_dev);
320 		struct net_device *lower_dev;
321 		struct list_head *iter;
322 
323 		next = d->next;
324 		dev = d->dev;
325 
326 		netdev_for_each_lower_dev(selected_dev, lower_dev, iter) {
327 			if (dev == lower_dev) {
328 				bring_down = false;
329 				break;
330 			}
331 		}
332 		if (bring_down) {
333 			pr_debug("IP-Config: Downing %s\n", dev->name);
334 			dev_change_flags(dev, d->flags, NULL);
335 		}
336 		kfree(d);
337 	}
338 	rtnl_unlock();
339 }
340 
341 /*
342  *	Interface to various network functions.
343  */
344 
345 static inline void
346 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
347 {
348 	sin->sin_family = AF_INET;
349 	sin->sin_addr.s_addr = addr;
350 	sin->sin_port = port;
351 }
352 
353 /*
354  *	Set up interface addresses and routes.
355  */
356 
357 static int __init ic_setup_if(void)
358 {
359 	struct ifreq ir;
360 	struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
361 	int err;
362 
363 	memset(&ir, 0, sizeof(ir));
364 	strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name);
365 	set_sockaddr(sin, ic_myaddr, 0);
366 	if ((err = devinet_ioctl(&init_net, SIOCSIFADDR, &ir)) < 0) {
367 		pr_err("IP-Config: Unable to set interface address (%d)\n",
368 		       err);
369 		return -1;
370 	}
371 	set_sockaddr(sin, ic_netmask, 0);
372 	if ((err = devinet_ioctl(&init_net, SIOCSIFNETMASK, &ir)) < 0) {
373 		pr_err("IP-Config: Unable to set interface netmask (%d)\n",
374 		       err);
375 		return -1;
376 	}
377 	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
378 	if ((err = devinet_ioctl(&init_net, SIOCSIFBRDADDR, &ir)) < 0) {
379 		pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
380 		       err);
381 		return -1;
382 	}
383 	/* Handle the case where we need non-standard MTU on the boot link (a network
384 	 * using jumbo frames, for instance).  If we can't set the mtu, don't error
385 	 * out, we'll try to muddle along.
386 	 */
387 	if (ic_dev_mtu != 0) {
388 		rtnl_lock();
389 		if ((err = dev_set_mtu(ic_dev->dev, ic_dev_mtu)) < 0)
390 			pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
391 			       ic_dev_mtu, err);
392 		rtnl_unlock();
393 	}
394 	return 0;
395 }
396 
397 static int __init ic_setup_routes(void)
398 {
399 	/* No need to setup device routes, only the default route... */
400 
401 	if (ic_gateway != NONE) {
402 		struct rtentry rm;
403 		int err;
404 
405 		memset(&rm, 0, sizeof(rm));
406 		if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
407 			pr_err("IP-Config: Gateway not on directly connected network\n");
408 			return -1;
409 		}
410 		set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
411 		set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
412 		set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
413 		rm.rt_flags = RTF_UP | RTF_GATEWAY;
414 		if ((err = ip_rt_ioctl(&init_net, SIOCADDRT, &rm)) < 0) {
415 			pr_err("IP-Config: Cannot add default route (%d)\n",
416 			       err);
417 			return -1;
418 		}
419 	}
420 
421 	return 0;
422 }
423 
424 /*
425  *	Fill in default values for all missing parameters.
426  */
427 
428 static int __init ic_defaults(void)
429 {
430 	/*
431 	 *	At this point we have no userspace running so need not
432 	 *	claim locks on system_utsname
433 	 */
434 
435 	if (!ic_host_name_set)
436 		sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
437 
438 	if (root_server_addr == NONE)
439 		root_server_addr = ic_servaddr;
440 
441 	if (ic_netmask == NONE) {
442 		if (IN_CLASSA(ntohl(ic_myaddr)))
443 			ic_netmask = htonl(IN_CLASSA_NET);
444 		else if (IN_CLASSB(ntohl(ic_myaddr)))
445 			ic_netmask = htonl(IN_CLASSB_NET);
446 		else if (IN_CLASSC(ntohl(ic_myaddr)))
447 			ic_netmask = htonl(IN_CLASSC_NET);
448 		else if (IN_CLASSE(ntohl(ic_myaddr)))
449 			ic_netmask = htonl(IN_CLASSE_NET);
450 		else {
451 			pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
452 			       &ic_myaddr);
453 			return -1;
454 		}
455 		pr_notice("IP-Config: Guessing netmask %pI4\n",
456 			  &ic_netmask);
457 	}
458 
459 	return 0;
460 }
461 
462 /*
463  *	RARP support.
464  */
465 
466 #ifdef IPCONFIG_RARP
467 
468 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
469 
470 static struct packet_type rarp_packet_type __initdata = {
471 	.type =	cpu_to_be16(ETH_P_RARP),
472 	.func =	ic_rarp_recv,
473 };
474 
475 static inline void __init ic_rarp_init(void)
476 {
477 	dev_add_pack(&rarp_packet_type);
478 }
479 
480 static inline void __init ic_rarp_cleanup(void)
481 {
482 	dev_remove_pack(&rarp_packet_type);
483 }
484 
485 /*
486  *  Process received RARP packet.
487  */
488 static int __init
489 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
490 {
491 	struct arphdr *rarp;
492 	unsigned char *rarp_ptr;
493 	__be32 sip, tip;
494 	unsigned char *tha;		/* t for "target" */
495 	struct ic_device *d;
496 
497 	if (!net_eq(dev_net(dev), &init_net))
498 		goto drop;
499 
500 	skb = skb_share_check(skb, GFP_ATOMIC);
501 	if (!skb)
502 		return NET_RX_DROP;
503 
504 	if (!pskb_may_pull(skb, sizeof(struct arphdr)))
505 		goto drop;
506 
507 	/* Basic sanity checks can be done without the lock.  */
508 	rarp = (struct arphdr *)skb_transport_header(skb);
509 
510 	/* If this test doesn't pass, it's not IP, or we should
511 	 * ignore it anyway.
512 	 */
513 	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
514 		goto drop;
515 
516 	/* If it's not a RARP reply, delete it. */
517 	if (rarp->ar_op != htons(ARPOP_RREPLY))
518 		goto drop;
519 
520 	/* If it's not Ethernet, delete it. */
521 	if (rarp->ar_pro != htons(ETH_P_IP))
522 		goto drop;
523 
524 	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
525 		goto drop;
526 
527 	/* OK, it is all there and looks valid, process... */
528 	rarp = (struct arphdr *)skb_transport_header(skb);
529 	rarp_ptr = (unsigned char *) (rarp + 1);
530 
531 	/* One reply at a time, please. */
532 	spin_lock(&ic_recv_lock);
533 
534 	/* If we already have a reply, just drop the packet */
535 	if (ic_got_reply)
536 		goto drop_unlock;
537 
538 	/* Find the ic_device that the packet arrived on */
539 	d = ic_first_dev;
540 	while (d && d->dev != dev)
541 		d = d->next;
542 	if (!d)
543 		goto drop_unlock;	/* should never happen */
544 
545 	/* Extract variable-width fields */
546 	rarp_ptr += dev->addr_len;
547 	memcpy(&sip, rarp_ptr, 4);
548 	rarp_ptr += 4;
549 	tha = rarp_ptr;
550 	rarp_ptr += dev->addr_len;
551 	memcpy(&tip, rarp_ptr, 4);
552 
553 	/* Discard packets which are not meant for us. */
554 	if (memcmp(tha, dev->dev_addr, dev->addr_len))
555 		goto drop_unlock;
556 
557 	/* Discard packets which are not from specified server. */
558 	if (ic_servaddr != NONE && ic_servaddr != sip)
559 		goto drop_unlock;
560 
561 	/* We have a winner! */
562 	ic_dev = d;
563 	if (ic_myaddr == NONE)
564 		ic_myaddr = tip;
565 	ic_servaddr = sip;
566 	ic_addrservaddr = sip;
567 	ic_got_reply = IC_RARP;
568 
569 drop_unlock:
570 	/* Show's over.  Nothing to see here.  */
571 	spin_unlock(&ic_recv_lock);
572 
573 drop:
574 	/* Throw the packet out. */
575 	kfree_skb(skb);
576 	return 0;
577 }
578 
579 
580 /*
581  *  Send RARP request packet over a single interface.
582  */
583 static void __init ic_rarp_send_if(struct ic_device *d)
584 {
585 	struct net_device *dev = d->dev;
586 	arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
587 		 dev->dev_addr, dev->dev_addr);
588 }
589 #endif
590 
591 /*
592  *  Predefine Nameservers
593  */
594 static inline void __init ic_nameservers_predef(void)
595 {
596 	int i;
597 
598 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
599 		ic_nameservers[i] = NONE;
600 }
601 
602 /* Predefine NTP servers */
603 static inline void __init ic_ntp_servers_predef(void)
604 {
605 	int i;
606 
607 	for (i = 0; i < CONF_NTP_SERVERS_MAX; i++)
608 		ic_ntp_servers[i] = NONE;
609 }
610 
611 /*
612  *	DHCP/BOOTP support.
613  */
614 
615 #ifdef IPCONFIG_BOOTP
616 
617 struct bootp_pkt {		/* BOOTP packet format */
618 	struct iphdr iph;	/* IP header */
619 	struct udphdr udph;	/* UDP header */
620 	u8 op;			/* 1=request, 2=reply */
621 	u8 htype;		/* HW address type */
622 	u8 hlen;		/* HW address length */
623 	u8 hops;		/* Used only by gateways */
624 	__be32 xid;		/* Transaction ID */
625 	__be16 secs;		/* Seconds since we started */
626 	__be16 flags;		/* Just what it says */
627 	__be32 client_ip;		/* Client's IP address if known */
628 	__be32 your_ip;		/* Assigned IP address */
629 	__be32 server_ip;		/* (Next, e.g. NFS) Server's IP address */
630 	__be32 relay_ip;		/* IP address of BOOTP relay */
631 	u8 hw_addr[16];		/* Client's HW address */
632 	u8 serv_name[64];	/* Server host name */
633 	u8 boot_file[128];	/* Name of boot file */
634 	u8 exten[312];		/* DHCP options / BOOTP vendor extensions */
635 };
636 
637 /* packet ops */
638 #define BOOTP_REQUEST	1
639 #define BOOTP_REPLY	2
640 
641 /* DHCP message types */
642 #define DHCPDISCOVER	1
643 #define DHCPOFFER	2
644 #define DHCPREQUEST	3
645 #define DHCPDECLINE	4
646 #define DHCPACK		5
647 #define DHCPNAK		6
648 #define DHCPRELEASE	7
649 #define DHCPINFORM	8
650 
651 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
652 
653 static struct packet_type bootp_packet_type __initdata = {
654 	.type =	cpu_to_be16(ETH_P_IP),
655 	.func =	ic_bootp_recv,
656 };
657 
658 /*
659  *  Initialize DHCP/BOOTP extension fields in the request.
660  */
661 
662 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
663 
664 #ifdef IPCONFIG_DHCP
665 
666 static void __init
667 ic_dhcp_init_options(u8 *options, struct ic_device *d)
668 {
669 	u8 mt = ((ic_servaddr == NONE)
670 		 ? DHCPDISCOVER : DHCPREQUEST);
671 	u8 *e = options;
672 	int len;
673 
674 	pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
675 
676 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
677 	e += 4;
678 
679 	*e++ = 53;		/* DHCP message type */
680 	*e++ = 1;
681 	*e++ = mt;
682 
683 	if (mt == DHCPREQUEST) {
684 		*e++ = 54;	/* Server ID (IP address) */
685 		*e++ = 4;
686 		memcpy(e, &ic_servaddr, 4);
687 		e += 4;
688 
689 		*e++ = 50;	/* Requested IP address */
690 		*e++ = 4;
691 		memcpy(e, &ic_myaddr, 4);
692 		e += 4;
693 	}
694 
695 	/* always? */
696 	{
697 		static const u8 ic_req_params[] = {
698 			1,	/* Subnet mask */
699 			3,	/* Default gateway */
700 			6,	/* DNS server */
701 			12,	/* Host name */
702 			15,	/* Domain name */
703 			17,	/* Boot path */
704 			26,	/* MTU */
705 			40,	/* NIS domain name */
706 			42,	/* NTP servers */
707 		};
708 
709 		*e++ = 55;	/* Parameter request list */
710 		*e++ = sizeof(ic_req_params);
711 		memcpy(e, ic_req_params, sizeof(ic_req_params));
712 		e += sizeof(ic_req_params);
713 
714 		if (ic_host_name_set) {
715 			*e++ = 12;	/* host-name */
716 			len = strlen(utsname()->nodename);
717 			*e++ = len;
718 			memcpy(e, utsname()->nodename, len);
719 			e += len;
720 		}
721 		if (*vendor_class_identifier) {
722 			pr_info("DHCP: sending class identifier \"%s\"\n",
723 				vendor_class_identifier);
724 			*e++ = 60;	/* Class-identifier */
725 			len = strlen(vendor_class_identifier);
726 			*e++ = len;
727 			memcpy(e, vendor_class_identifier, len);
728 			e += len;
729 		}
730 		len = strlen(dhcp_client_identifier + 1);
731 		/* the minimum length of identifier is 2, include 1 byte type,
732 		 * and can not be larger than the length of options
733 		 */
734 		if (len >= 1 && len < 312 - (e - options) - 1) {
735 			*e++ = 61;
736 			*e++ = len + 1;
737 			memcpy(e, dhcp_client_identifier, len + 1);
738 			e += len + 1;
739 		}
740 	}
741 
742 	*e++ = 255;	/* End of the list */
743 }
744 
745 #endif /* IPCONFIG_DHCP */
746 
747 static void __init ic_bootp_init_ext(u8 *e)
748 {
749 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
750 	e += 4;
751 	*e++ = 1;		/* Subnet mask request */
752 	*e++ = 4;
753 	e += 4;
754 	*e++ = 3;		/* Default gateway request */
755 	*e++ = 4;
756 	e += 4;
757 #if CONF_NAMESERVERS_MAX > 0
758 	*e++ = 6;		/* (DNS) name server request */
759 	*e++ = 4 * CONF_NAMESERVERS_MAX;
760 	e += 4 * CONF_NAMESERVERS_MAX;
761 #endif
762 	*e++ = 12;		/* Host name request */
763 	*e++ = 32;
764 	e += 32;
765 	*e++ = 40;		/* NIS Domain name request */
766 	*e++ = 32;
767 	e += 32;
768 	*e++ = 17;		/* Boot path */
769 	*e++ = 40;
770 	e += 40;
771 
772 	*e++ = 57;		/* set extension buffer size for reply */
773 	*e++ = 2;
774 	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
775 	*e++ = 150;
776 
777 	*e++ = 255;		/* End of the list */
778 }
779 
780 
781 /*
782  *  Initialize the DHCP/BOOTP mechanism.
783  */
784 static inline void __init ic_bootp_init(void)
785 {
786 	/* Re-initialise all name servers and NTP servers to NONE, in case any
787 	 * were set via the "ip=" or "nfsaddrs=" kernel command line parameters:
788 	 * any IP addresses specified there will already have been decoded but
789 	 * are no longer needed
790 	 */
791 	ic_nameservers_predef();
792 	ic_ntp_servers_predef();
793 
794 	dev_add_pack(&bootp_packet_type);
795 }
796 
797 
798 /*
799  *  DHCP/BOOTP cleanup.
800  */
801 static inline void __init ic_bootp_cleanup(void)
802 {
803 	dev_remove_pack(&bootp_packet_type);
804 }
805 
806 
807 /*
808  *  Send DHCP/BOOTP request to single interface.
809  */
810 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
811 {
812 	struct net_device *dev = d->dev;
813 	struct sk_buff *skb;
814 	struct bootp_pkt *b;
815 	struct iphdr *h;
816 	int hlen = LL_RESERVED_SPACE(dev);
817 	int tlen = dev->needed_tailroom;
818 
819 	/* Allocate packet */
820 	skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
821 			GFP_KERNEL);
822 	if (!skb)
823 		return;
824 	skb_reserve(skb, hlen);
825 	b = skb_put_zero(skb, sizeof(struct bootp_pkt));
826 
827 	/* Construct IP header */
828 	skb_reset_network_header(skb);
829 	h = ip_hdr(skb);
830 	h->version = 4;
831 	h->ihl = 5;
832 	h->tot_len = htons(sizeof(struct bootp_pkt));
833 	h->frag_off = htons(IP_DF);
834 	h->ttl = 64;
835 	h->protocol = IPPROTO_UDP;
836 	h->daddr = htonl(INADDR_BROADCAST);
837 	h->check = ip_fast_csum((unsigned char *) h, h->ihl);
838 
839 	/* Construct UDP header */
840 	b->udph.source = htons(68);
841 	b->udph.dest = htons(67);
842 	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
843 	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
844 
845 	/* Construct DHCP/BOOTP header */
846 	b->op = BOOTP_REQUEST;
847 	if (dev->type < 256) /* check for false types */
848 		b->htype = dev->type;
849 	else if (dev->type == ARPHRD_FDDI)
850 		b->htype = ARPHRD_ETHER;
851 	else {
852 		pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
853 			dev->name);
854 		b->htype = dev->type; /* can cause undefined behavior */
855 	}
856 
857 	/* server_ip and your_ip address are both already zero per RFC2131 */
858 	b->hlen = dev->addr_len;
859 	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
860 	b->secs = htons(jiffies_diff / HZ);
861 	b->xid = d->xid;
862 
863 	/* add DHCP options or BOOTP extensions */
864 #ifdef IPCONFIG_DHCP
865 	if (ic_proto_enabled & IC_USE_DHCP)
866 		ic_dhcp_init_options(b->exten, d);
867 	else
868 #endif
869 		ic_bootp_init_ext(b->exten);
870 
871 	/* Chain packet down the line... */
872 	skb->dev = dev;
873 	skb->protocol = htons(ETH_P_IP);
874 	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
875 			    dev->broadcast, dev->dev_addr, skb->len) < 0) {
876 		kfree_skb(skb);
877 		printk("E");
878 		return;
879 	}
880 
881 	if (dev_queue_xmit(skb) < 0)
882 		printk("E");
883 }
884 
885 
886 /*
887  *  Copy BOOTP-supplied string if not already set.
888  */
889 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
890 {
891 	if (!len)
892 		return 0;
893 	if (len > max-1)
894 		len = max-1;
895 	memcpy(dest, src, len);
896 	dest[len] = '\0';
897 	return 1;
898 }
899 
900 
901 /*
902  *  Process BOOTP extensions.
903  */
904 static void __init ic_do_bootp_ext(u8 *ext)
905 {
906 	u8 servers;
907 	int i;
908 	__be16 mtu;
909 
910 	u8 *c;
911 
912 	pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
913 	for (c=ext+2; c<ext+2+ext[1]; c++)
914 		pr_debug(" %02x", *c);
915 	pr_debug("\n");
916 
917 	switch (*ext++) {
918 	case 1:		/* Subnet mask */
919 		if (ic_netmask == NONE)
920 			memcpy(&ic_netmask, ext+1, 4);
921 		break;
922 	case 3:		/* Default gateway */
923 		if (ic_gateway == NONE)
924 			memcpy(&ic_gateway, ext+1, 4);
925 		break;
926 	case 6:		/* DNS server */
927 		servers= *ext/4;
928 		if (servers > CONF_NAMESERVERS_MAX)
929 			servers = CONF_NAMESERVERS_MAX;
930 		for (i = 0; i < servers; i++) {
931 			if (ic_nameservers[i] == NONE)
932 				memcpy(&ic_nameservers[i], ext+1+4*i, 4);
933 		}
934 		break;
935 	case 12:	/* Host name */
936 		ic_bootp_string(utsname()->nodename, ext+1, *ext,
937 				__NEW_UTS_LEN);
938 		ic_host_name_set = 1;
939 		break;
940 	case 15:	/* Domain name (DNS) */
941 		ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
942 		break;
943 	case 17:	/* Root path */
944 		if (!root_server_path[0])
945 			ic_bootp_string(root_server_path, ext+1, *ext,
946 					sizeof(root_server_path));
947 		break;
948 	case 26:	/* Interface MTU */
949 		memcpy(&mtu, ext+1, sizeof(mtu));
950 		ic_dev_mtu = ntohs(mtu);
951 		break;
952 	case 40:	/* NIS Domain name (_not_ DNS) */
953 		ic_bootp_string(utsname()->domainname, ext+1, *ext,
954 				__NEW_UTS_LEN);
955 		break;
956 	case 42:	/* NTP servers */
957 		servers = *ext / 4;
958 		if (servers > CONF_NTP_SERVERS_MAX)
959 			servers = CONF_NTP_SERVERS_MAX;
960 		for (i = 0; i < servers; i++) {
961 			if (ic_ntp_servers[i] == NONE)
962 				memcpy(&ic_ntp_servers[i], ext+1+4*i, 4);
963 		}
964 		break;
965 	}
966 }
967 
968 
969 /*
970  *  Receive BOOTP reply.
971  */
972 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
973 {
974 	struct bootp_pkt *b;
975 	struct iphdr *h;
976 	struct ic_device *d;
977 	int len, ext_len;
978 
979 	if (!net_eq(dev_net(dev), &init_net))
980 		goto drop;
981 
982 	/* Perform verifications before taking the lock.  */
983 	if (skb->pkt_type == PACKET_OTHERHOST)
984 		goto drop;
985 
986 	skb = skb_share_check(skb, GFP_ATOMIC);
987 	if (!skb)
988 		return NET_RX_DROP;
989 
990 	if (!pskb_may_pull(skb,
991 			   sizeof(struct iphdr) +
992 			   sizeof(struct udphdr)))
993 		goto drop;
994 
995 	b = (struct bootp_pkt *)skb_network_header(skb);
996 	h = &b->iph;
997 
998 	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
999 		goto drop;
1000 
1001 	/* Fragments are not supported */
1002 	if (ip_is_fragment(h)) {
1003 		net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
1004 		goto drop;
1005 	}
1006 
1007 	if (skb->len < ntohs(h->tot_len))
1008 		goto drop;
1009 
1010 	if (ip_fast_csum((char *) h, h->ihl))
1011 		goto drop;
1012 
1013 	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
1014 		goto drop;
1015 
1016 	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
1017 		goto drop;
1018 
1019 	len = ntohs(b->udph.len) - sizeof(struct udphdr);
1020 	ext_len = len - (sizeof(*b) -
1021 			 sizeof(struct iphdr) -
1022 			 sizeof(struct udphdr) -
1023 			 sizeof(b->exten));
1024 	if (ext_len < 0)
1025 		goto drop;
1026 
1027 	/* Ok the front looks good, make sure we can get at the rest.  */
1028 	if (!pskb_may_pull(skb, skb->len))
1029 		goto drop;
1030 
1031 	b = (struct bootp_pkt *)skb_network_header(skb);
1032 	h = &b->iph;
1033 
1034 	/* One reply at a time, please. */
1035 	spin_lock(&ic_recv_lock);
1036 
1037 	/* If we already have a reply, just drop the packet */
1038 	if (ic_got_reply)
1039 		goto drop_unlock;
1040 
1041 	/* Find the ic_device that the packet arrived on */
1042 	d = ic_first_dev;
1043 	while (d && d->dev != dev)
1044 		d = d->next;
1045 	if (!d)
1046 		goto drop_unlock;  /* should never happen */
1047 
1048 	/* Is it a reply to our BOOTP request? */
1049 	if (b->op != BOOTP_REPLY ||
1050 	    b->xid != d->xid) {
1051 		net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1052 				    d->dev->name, b->op, b->xid);
1053 		goto drop_unlock;
1054 	}
1055 
1056 	/* Parse extensions */
1057 	if (ext_len >= 4 &&
1058 	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1059 		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1060 		u8 *ext;
1061 
1062 #ifdef IPCONFIG_DHCP
1063 		if (ic_proto_enabled & IC_USE_DHCP) {
1064 			__be32 server_id = NONE;
1065 			int mt = 0;
1066 
1067 			ext = &b->exten[4];
1068 			while (ext < end && *ext != 0xff) {
1069 				u8 *opt = ext++;
1070 				if (*opt == 0)	/* Padding */
1071 					continue;
1072 				ext += *ext + 1;
1073 				if (ext >= end)
1074 					break;
1075 				switch (*opt) {
1076 				case 53:	/* Message type */
1077 					if (opt[1])
1078 						mt = opt[2];
1079 					break;
1080 				case 54:	/* Server ID (IP address) */
1081 					if (opt[1] >= 4)
1082 						memcpy(&server_id, opt + 2, 4);
1083 					break;
1084 				}
1085 			}
1086 
1087 			pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1088 
1089 			switch (mt) {
1090 			case DHCPOFFER:
1091 				/* While in the process of accepting one offer,
1092 				 * ignore all others.
1093 				 */
1094 				if (ic_myaddr != NONE)
1095 					goto drop_unlock;
1096 
1097 				/* Let's accept that offer. */
1098 				ic_myaddr = b->your_ip;
1099 				ic_servaddr = server_id;
1100 				pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1101 					 &ic_myaddr, &b->iph.saddr);
1102 				/* The DHCP indicated server address takes
1103 				 * precedence over the bootp header one if
1104 				 * they are different.
1105 				 */
1106 				if ((server_id != NONE) &&
1107 				    (b->server_ip != server_id))
1108 					b->server_ip = ic_servaddr;
1109 				break;
1110 
1111 			case DHCPACK:
1112 				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1113 					goto drop_unlock;
1114 
1115 				/* Yeah! */
1116 				break;
1117 
1118 			default:
1119 				/* Urque.  Forget it*/
1120 				ic_myaddr = NONE;
1121 				ic_servaddr = NONE;
1122 				goto drop_unlock;
1123 			}
1124 
1125 			ic_dhcp_msgtype = mt;
1126 
1127 		}
1128 #endif /* IPCONFIG_DHCP */
1129 
1130 		ext = &b->exten[4];
1131 		while (ext < end && *ext != 0xff) {
1132 			u8 *opt = ext++;
1133 			if (*opt == 0)	/* Padding */
1134 				continue;
1135 			ext += *ext + 1;
1136 			if (ext < end)
1137 				ic_do_bootp_ext(opt);
1138 		}
1139 	}
1140 
1141 	/* We have a winner! */
1142 	ic_dev = d;
1143 	ic_myaddr = b->your_ip;
1144 	ic_servaddr = b->server_ip;
1145 	ic_addrservaddr = b->iph.saddr;
1146 	if (ic_gateway == NONE && b->relay_ip)
1147 		ic_gateway = b->relay_ip;
1148 	if (ic_nameservers[0] == NONE)
1149 		ic_nameservers[0] = ic_servaddr;
1150 	ic_got_reply = IC_BOOTP;
1151 
1152 drop_unlock:
1153 	/* Show's over.  Nothing to see here.  */
1154 	spin_unlock(&ic_recv_lock);
1155 
1156 drop:
1157 	/* Throw the packet out. */
1158 	kfree_skb(skb);
1159 
1160 	return 0;
1161 }
1162 
1163 
1164 #endif
1165 
1166 
1167 /*
1168  *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
1169  */
1170 
1171 #ifdef IPCONFIG_DYNAMIC
1172 
1173 static int __init ic_dynamic(void)
1174 {
1175 	int retries;
1176 	struct ic_device *d;
1177 	unsigned long start_jiffies, timeout, jiff;
1178 	int do_bootp = ic_proto_have_if & IC_BOOTP;
1179 	int do_rarp = ic_proto_have_if & IC_RARP;
1180 
1181 	/*
1182 	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1183 	 * This routine gets only called when some pieces of information
1184 	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1185 	 */
1186 	if (!ic_proto_enabled) {
1187 		pr_err("IP-Config: Incomplete network configuration information\n");
1188 		return -1;
1189 	}
1190 
1191 #ifdef IPCONFIG_BOOTP
1192 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1193 		pr_err("DHCP/BOOTP: No suitable device found\n");
1194 #endif
1195 #ifdef IPCONFIG_RARP
1196 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1197 		pr_err("RARP: No suitable device found\n");
1198 #endif
1199 
1200 	if (!ic_proto_have_if)
1201 		/* Error message already printed */
1202 		return -1;
1203 
1204 	/*
1205 	 * Setup protocols
1206 	 */
1207 #ifdef IPCONFIG_BOOTP
1208 	if (do_bootp)
1209 		ic_bootp_init();
1210 #endif
1211 #ifdef IPCONFIG_RARP
1212 	if (do_rarp)
1213 		ic_rarp_init();
1214 #endif
1215 
1216 	/*
1217 	 * Send requests and wait, until we get an answer. This loop
1218 	 * seems to be a terrible waste of CPU time, but actually there is
1219 	 * only one process running at all, so we don't need to use any
1220 	 * scheduler functions.
1221 	 * [Actually we could now, but the nothing else running note still
1222 	 *  applies.. - AC]
1223 	 */
1224 	pr_notice("Sending %s%s%s requests .",
1225 		  do_bootp
1226 		  ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1227 		  (do_bootp && do_rarp) ? " and " : "",
1228 		  do_rarp ? "RARP" : "");
1229 
1230 	start_jiffies = jiffies;
1231 	d = ic_first_dev;
1232 	retries = CONF_SEND_RETRIES;
1233 	get_random_bytes(&timeout, sizeof(timeout));
1234 	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1235 	for (;;) {
1236 #ifdef IPCONFIG_BOOTP
1237 		if (do_bootp && (d->able & IC_BOOTP))
1238 			ic_bootp_send_if(d, jiffies - start_jiffies);
1239 #endif
1240 #ifdef IPCONFIG_RARP
1241 		if (do_rarp && (d->able & IC_RARP))
1242 			ic_rarp_send_if(d);
1243 #endif
1244 
1245 		if (!d->next) {
1246 			jiff = jiffies + timeout;
1247 			while (time_before(jiffies, jiff) && !ic_got_reply)
1248 				schedule_timeout_uninterruptible(1);
1249 		}
1250 #ifdef IPCONFIG_DHCP
1251 		/* DHCP isn't done until we get a DHCPACK. */
1252 		if ((ic_got_reply & IC_BOOTP) &&
1253 		    (ic_proto_enabled & IC_USE_DHCP) &&
1254 		    ic_dhcp_msgtype != DHCPACK) {
1255 			ic_got_reply = 0;
1256 			/* continue on device that got the reply */
1257 			d = ic_dev;
1258 			pr_cont(",");
1259 			continue;
1260 		}
1261 #endif /* IPCONFIG_DHCP */
1262 
1263 		if (ic_got_reply) {
1264 			pr_cont(" OK\n");
1265 			break;
1266 		}
1267 
1268 		if ((d = d->next))
1269 			continue;
1270 
1271 		if (! --retries) {
1272 			pr_cont(" timed out!\n");
1273 			break;
1274 		}
1275 
1276 		d = ic_first_dev;
1277 
1278 		timeout = timeout CONF_TIMEOUT_MULT;
1279 		if (timeout > CONF_TIMEOUT_MAX)
1280 			timeout = CONF_TIMEOUT_MAX;
1281 
1282 		pr_cont(".");
1283 	}
1284 
1285 #ifdef IPCONFIG_BOOTP
1286 	if (do_bootp)
1287 		ic_bootp_cleanup();
1288 #endif
1289 #ifdef IPCONFIG_RARP
1290 	if (do_rarp)
1291 		ic_rarp_cleanup();
1292 #endif
1293 
1294 	if (!ic_got_reply) {
1295 		ic_myaddr = NONE;
1296 		return -1;
1297 	}
1298 
1299 	pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1300 		((ic_got_reply & IC_RARP) ? "RARP"
1301 		: (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1302 		&ic_addrservaddr, &ic_myaddr);
1303 
1304 	return 0;
1305 }
1306 
1307 #endif /* IPCONFIG_DYNAMIC */
1308 
1309 #ifdef CONFIG_PROC_FS
1310 /* proc_dir_entry for /proc/net/ipconfig */
1311 static struct proc_dir_entry *ipconfig_dir;
1312 
1313 /* Name servers: */
1314 static int pnp_seq_show(struct seq_file *seq, void *v)
1315 {
1316 	int i;
1317 
1318 	if (ic_proto_used & IC_PROTO)
1319 		seq_printf(seq, "#PROTO: %s\n",
1320 			   (ic_proto_used & IC_RARP) ? "RARP"
1321 			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1322 	else
1323 		seq_puts(seq, "#MANUAL\n");
1324 
1325 	if (ic_domain[0])
1326 		seq_printf(seq,
1327 			   "domain %s\n", ic_domain);
1328 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1329 		if (ic_nameservers[i] != NONE)
1330 			seq_printf(seq, "nameserver %pI4\n",
1331 				   &ic_nameservers[i]);
1332 	}
1333 	if (ic_servaddr != NONE)
1334 		seq_printf(seq, "bootserver %pI4\n",
1335 			   &ic_servaddr);
1336 	return 0;
1337 }
1338 
1339 /* Create the /proc/net/ipconfig directory */
1340 static int __init ipconfig_proc_net_init(void)
1341 {
1342 	ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net);
1343 	if (!ipconfig_dir)
1344 		return -ENOMEM;
1345 
1346 	return 0;
1347 }
1348 
1349 /* Create a new file under /proc/net/ipconfig */
1350 static int ipconfig_proc_net_create(const char *name,
1351 				    const struct proc_ops *proc_ops)
1352 {
1353 	char *pname;
1354 	struct proc_dir_entry *p;
1355 
1356 	if (!ipconfig_dir)
1357 		return -ENOMEM;
1358 
1359 	pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name);
1360 	if (!pname)
1361 		return -ENOMEM;
1362 
1363 	p = proc_create(pname, 0444, init_net.proc_net, proc_ops);
1364 	kfree(pname);
1365 	if (!p)
1366 		return -ENOMEM;
1367 
1368 	return 0;
1369 }
1370 
1371 /* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */
1372 static int ntp_servers_show(struct seq_file *seq, void *v)
1373 {
1374 	int i;
1375 
1376 	for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1377 		if (ic_ntp_servers[i] != NONE)
1378 			seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]);
1379 	}
1380 	return 0;
1381 }
1382 DEFINE_PROC_SHOW_ATTRIBUTE(ntp_servers);
1383 #endif /* CONFIG_PROC_FS */
1384 
1385 /*
1386  *  Extract IP address from the parameter string if needed. Note that we
1387  *  need to have root_server_addr set _before_ IPConfig gets called as it
1388  *  can override it.
1389  */
1390 __be32 __init root_nfs_parse_addr(char *name)
1391 {
1392 	__be32 addr;
1393 	int octets = 0;
1394 	char *cp, *cq;
1395 
1396 	cp = cq = name;
1397 	while (octets < 4) {
1398 		while (*cp >= '0' && *cp <= '9')
1399 			cp++;
1400 		if (cp == cq || cp - cq > 3)
1401 			break;
1402 		if (*cp == '.' || octets == 3)
1403 			octets++;
1404 		if (octets < 4)
1405 			cp++;
1406 		cq = cp;
1407 	}
1408 	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1409 		if (*cp == ':')
1410 			*cp++ = '\0';
1411 		addr = in_aton(name);
1412 		memmove(name, cp, strlen(cp) + 1);
1413 	} else
1414 		addr = NONE;
1415 
1416 	return addr;
1417 }
1418 
1419 #define DEVICE_WAIT_MAX		12 /* 12 seconds */
1420 
1421 static int __init wait_for_devices(void)
1422 {
1423 	int i;
1424 
1425 	for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1426 		struct net_device *dev;
1427 		int found = 0;
1428 
1429 		/* make sure deferred device probes are finished */
1430 		wait_for_device_probe();
1431 
1432 		rtnl_lock();
1433 		for_each_netdev(&init_net, dev) {
1434 			if (ic_is_init_dev(dev)) {
1435 				found = 1;
1436 				break;
1437 			}
1438 		}
1439 		rtnl_unlock();
1440 		if (found)
1441 			return 0;
1442 		ssleep(1);
1443 	}
1444 	return -ENODEV;
1445 }
1446 
1447 /*
1448  *	IP Autoconfig dispatcher.
1449  */
1450 
1451 static int __init ip_auto_config(void)
1452 {
1453 	__be32 addr;
1454 #ifdef IPCONFIG_DYNAMIC
1455 	int retries = CONF_OPEN_RETRIES;
1456 #endif
1457 	int err;
1458 	unsigned int i, count;
1459 
1460 	/* Initialise all name servers and NTP servers to NONE (but only if the
1461 	 * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded,
1462 	 * otherwise we'll overwrite the IP addresses specified there)
1463 	 */
1464 	if (ic_set_manually == 0) {
1465 		ic_nameservers_predef();
1466 		ic_ntp_servers_predef();
1467 	}
1468 
1469 #ifdef CONFIG_PROC_FS
1470 	proc_create_single("pnp", 0444, init_net.proc_net, pnp_seq_show);
1471 
1472 	if (ipconfig_proc_net_init() == 0)
1473 		ipconfig_proc_net_create("ntp_servers", &ntp_servers_proc_ops);
1474 #endif /* CONFIG_PROC_FS */
1475 
1476 	if (!ic_enable)
1477 		return 0;
1478 
1479 	pr_debug("IP-Config: Entered.\n");
1480 #ifdef IPCONFIG_DYNAMIC
1481  try_try_again:
1482 #endif
1483 	/* Wait for devices to appear */
1484 	err = wait_for_devices();
1485 	if (err)
1486 		return err;
1487 
1488 	/* Setup all network devices */
1489 	err = ic_open_devs();
1490 	if (err)
1491 		return err;
1492 
1493 	/* Give drivers a chance to settle */
1494 	msleep(CONF_POST_OPEN);
1495 
1496 	/*
1497 	 * If the config information is insufficient (e.g., our IP address or
1498 	 * IP address of the boot server is missing or we have multiple network
1499 	 * interfaces and no default was set), use BOOTP or RARP to get the
1500 	 * missing values.
1501 	 */
1502 	if (ic_myaddr == NONE ||
1503 #if defined(CONFIG_ROOT_NFS) || defined(CONFIG_CIFS_ROOT)
1504 	    (root_server_addr == NONE &&
1505 	     ic_servaddr == NONE &&
1506 	     (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) ||
1507 #endif
1508 	    ic_first_dev->next) {
1509 #ifdef IPCONFIG_DYNAMIC
1510 		if (ic_dynamic() < 0) {
1511 			ic_close_devs();
1512 
1513 			/*
1514 			 * I don't know why, but sometimes the
1515 			 * eepro100 driver (at least) gets upset and
1516 			 * doesn't work the first time it's opened.
1517 			 * But then if you close it and reopen it, it
1518 			 * works just fine.  So we need to try that at
1519 			 * least once before giving up.
1520 			 *
1521 			 * Also, if the root will be NFS-mounted, we
1522 			 * have nowhere to go if DHCP fails.  So we
1523 			 * just have to keep trying forever.
1524 			 *
1525 			 * 				-- Chip
1526 			 */
1527 #ifdef CONFIG_ROOT_NFS
1528 			if (ROOT_DEV ==  Root_NFS) {
1529 				pr_err("IP-Config: Retrying forever (NFS root)...\n");
1530 				goto try_try_again;
1531 			}
1532 #endif
1533 #ifdef CONFIG_CIFS_ROOT
1534 			if (ROOT_DEV == Root_CIFS) {
1535 				pr_err("IP-Config: Retrying forever (CIFS root)...\n");
1536 				goto try_try_again;
1537 			}
1538 #endif
1539 
1540 			if (--retries) {
1541 				pr_err("IP-Config: Reopening network devices...\n");
1542 				goto try_try_again;
1543 			}
1544 
1545 			/* Oh, well.  At least we tried. */
1546 			pr_err("IP-Config: Auto-configuration of network failed\n");
1547 			return -1;
1548 		}
1549 #else /* !DYNAMIC */
1550 		pr_err("IP-Config: Incomplete network configuration information\n");
1551 		ic_close_devs();
1552 		return -1;
1553 #endif /* IPCONFIG_DYNAMIC */
1554 	} else {
1555 		/* Device selected manually or only one device -> use it */
1556 		ic_dev = ic_first_dev;
1557 	}
1558 
1559 	addr = root_nfs_parse_addr(root_server_path);
1560 	if (root_server_addr == NONE)
1561 		root_server_addr = addr;
1562 
1563 	/*
1564 	 * Use defaults wherever applicable.
1565 	 */
1566 	if (ic_defaults() < 0)
1567 		return -1;
1568 
1569 	/*
1570 	 * Record which protocol was actually used.
1571 	 */
1572 #ifdef IPCONFIG_DYNAMIC
1573 	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1574 #endif
1575 
1576 #ifndef IPCONFIG_SILENT
1577 	/*
1578 	 * Clue in the operator.
1579 	 */
1580 	pr_info("IP-Config: Complete:\n");
1581 
1582 	pr_info("     device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1583 		ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1584 		&ic_myaddr, &ic_netmask, &ic_gateway);
1585 	pr_info("     host=%s, domain=%s, nis-domain=%s\n",
1586 		utsname()->nodename, ic_domain, utsname()->domainname);
1587 	pr_info("     bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1588 		&ic_servaddr, &root_server_addr, root_server_path);
1589 	if (ic_dev_mtu)
1590 		pr_cont(", mtu=%d", ic_dev_mtu);
1591 	/* Name servers (if any): */
1592 	for (i = 0, count = 0; i < CONF_NAMESERVERS_MAX; i++) {
1593 		if (ic_nameservers[i] != NONE) {
1594 			if (i == 0)
1595 				pr_info("     nameserver%u=%pI4",
1596 					i, &ic_nameservers[i]);
1597 			else
1598 				pr_cont(", nameserver%u=%pI4",
1599 					i, &ic_nameservers[i]);
1600 
1601 			count++;
1602 		}
1603 		if ((i + 1 == CONF_NAMESERVERS_MAX) && count > 0)
1604 			pr_cont("\n");
1605 	}
1606 	/* NTP servers (if any): */
1607 	for (i = 0, count = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1608 		if (ic_ntp_servers[i] != NONE) {
1609 			if (i == 0)
1610 				pr_info("     ntpserver%u=%pI4",
1611 					i, &ic_ntp_servers[i]);
1612 			else
1613 				pr_cont(", ntpserver%u=%pI4",
1614 					i, &ic_ntp_servers[i]);
1615 
1616 			count++;
1617 		}
1618 		if ((i + 1 == CONF_NTP_SERVERS_MAX) && count > 0)
1619 			pr_cont("\n");
1620 	}
1621 #endif /* !SILENT */
1622 
1623 	/*
1624 	 * Close all network devices except the device we've
1625 	 * autoconfigured and set up routes.
1626 	 */
1627 	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1628 		err = -1;
1629 	else
1630 		err = 0;
1631 
1632 	ic_close_devs();
1633 
1634 	return err;
1635 }
1636 
1637 late_initcall(ip_auto_config);
1638 
1639 
1640 /*
1641  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1642  *  command line parameter.  See Documentation/admin-guide/nfs/nfsroot.rst.
1643  */
1644 static int __init ic_proto_name(char *name)
1645 {
1646 	if (!strcmp(name, "on") || !strcmp(name, "any")) {
1647 		return 1;
1648 	}
1649 	if (!strcmp(name, "off") || !strcmp(name, "none")) {
1650 		return 0;
1651 	}
1652 #ifdef CONFIG_IP_PNP_DHCP
1653 	else if (!strncmp(name, "dhcp", 4)) {
1654 		char *client_id;
1655 
1656 		ic_proto_enabled &= ~IC_RARP;
1657 		client_id = strstr(name, "dhcp,");
1658 		if (client_id) {
1659 			char *v;
1660 
1661 			client_id = client_id + 5;
1662 			v = strchr(client_id, ',');
1663 			if (!v)
1664 				return 1;
1665 			*v = 0;
1666 			if (kstrtou8(client_id, 0, dhcp_client_identifier))
1667 				pr_debug("DHCP: Invalid client identifier type\n");
1668 			strncpy(dhcp_client_identifier + 1, v + 1, 251);
1669 			*v = ',';
1670 		}
1671 		return 1;
1672 	}
1673 #endif
1674 #ifdef CONFIG_IP_PNP_BOOTP
1675 	else if (!strcmp(name, "bootp")) {
1676 		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1677 		return 1;
1678 	}
1679 #endif
1680 #ifdef CONFIG_IP_PNP_RARP
1681 	else if (!strcmp(name, "rarp")) {
1682 		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1683 		return 1;
1684 	}
1685 #endif
1686 #ifdef IPCONFIG_DYNAMIC
1687 	else if (!strcmp(name, "both")) {
1688 		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1689 		return 1;
1690 	}
1691 #endif
1692 	return 0;
1693 }
1694 
1695 static int __init ip_auto_config_setup(char *addrs)
1696 {
1697 	char *cp, *ip, *dp;
1698 	int num = 0;
1699 
1700 	ic_set_manually = 1;
1701 	ic_enable = 1;
1702 
1703 	/*
1704 	 * If any dhcp, bootp etc options are set, leave autoconfig on
1705 	 * and skip the below static IP processing.
1706 	 */
1707 	if (ic_proto_name(addrs))
1708 		return 1;
1709 
1710 	/* If no static IP is given, turn off autoconfig and bail.  */
1711 	if (*addrs == 0 ||
1712 	    strcmp(addrs, "off") == 0 ||
1713 	    strcmp(addrs, "none") == 0) {
1714 		ic_enable = 0;
1715 		return 1;
1716 	}
1717 
1718 	/* Initialise all name servers and NTP servers to NONE */
1719 	ic_nameservers_predef();
1720 	ic_ntp_servers_predef();
1721 
1722 	/* Parse string for static IP assignment.  */
1723 	ip = addrs;
1724 	while (ip && *ip) {
1725 		if ((cp = strchr(ip, ':')))
1726 			*cp++ = '\0';
1727 		if (strlen(ip) > 0) {
1728 			pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1729 			switch (num) {
1730 			case 0:
1731 				if ((ic_myaddr = in_aton(ip)) == ANY)
1732 					ic_myaddr = NONE;
1733 				break;
1734 			case 1:
1735 				if ((ic_servaddr = in_aton(ip)) == ANY)
1736 					ic_servaddr = NONE;
1737 				break;
1738 			case 2:
1739 				if ((ic_gateway = in_aton(ip)) == ANY)
1740 					ic_gateway = NONE;
1741 				break;
1742 			case 3:
1743 				if ((ic_netmask = in_aton(ip)) == ANY)
1744 					ic_netmask = NONE;
1745 				break;
1746 			case 4:
1747 				if ((dp = strchr(ip, '.'))) {
1748 					*dp++ = '\0';
1749 					strlcpy(utsname()->domainname, dp,
1750 						sizeof(utsname()->domainname));
1751 				}
1752 				strlcpy(utsname()->nodename, ip,
1753 					sizeof(utsname()->nodename));
1754 				ic_host_name_set = 1;
1755 				break;
1756 			case 5:
1757 				strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1758 				break;
1759 			case 6:
1760 				if (ic_proto_name(ip) == 0 &&
1761 				    ic_myaddr == NONE) {
1762 					ic_enable = 0;
1763 				}
1764 				break;
1765 			case 7:
1766 				if (CONF_NAMESERVERS_MAX >= 1) {
1767 					ic_nameservers[0] = in_aton(ip);
1768 					if (ic_nameservers[0] == ANY)
1769 						ic_nameservers[0] = NONE;
1770 				}
1771 				break;
1772 			case 8:
1773 				if (CONF_NAMESERVERS_MAX >= 2) {
1774 					ic_nameservers[1] = in_aton(ip);
1775 					if (ic_nameservers[1] == ANY)
1776 						ic_nameservers[1] = NONE;
1777 				}
1778 				break;
1779 			case 9:
1780 				if (CONF_NTP_SERVERS_MAX >= 1) {
1781 					ic_ntp_servers[0] = in_aton(ip);
1782 					if (ic_ntp_servers[0] == ANY)
1783 						ic_ntp_servers[0] = NONE;
1784 				}
1785 				break;
1786 			}
1787 		}
1788 		ip = cp;
1789 		num++;
1790 	}
1791 
1792 	return 1;
1793 }
1794 __setup("ip=", ip_auto_config_setup);
1795 
1796 static int __init nfsaddrs_config_setup(char *addrs)
1797 {
1798 	return ip_auto_config_setup(addrs);
1799 }
1800 __setup("nfsaddrs=", nfsaddrs_config_setup);
1801 
1802 static int __init vendor_class_identifier_setup(char *addrs)
1803 {
1804 	if (strlcpy(vendor_class_identifier, addrs,
1805 		    sizeof(vendor_class_identifier))
1806 	    >= sizeof(vendor_class_identifier))
1807 		pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1808 			vendor_class_identifier);
1809 	return 1;
1810 }
1811 __setup("dhcpclass=", vendor_class_identifier_setup);
1812 
1813 static int __init set_carrier_timeout(char *str)
1814 {
1815 	ssize_t ret;
1816 
1817 	if (!str)
1818 		return 0;
1819 
1820 	ret = kstrtouint(str, 0, &carrier_timeout);
1821 	if (ret)
1822 		return 0;
1823 
1824 	return 1;
1825 }
1826 __setup("carrier_timeout=", set_carrier_timeout);
1827