xref: /openbmc/linux/net/ipv4/ipconfig.c (revision 877013bc)
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 ? ic_dev->dev : NULL;
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;
321 		struct list_head *iter;
322 
323 		next = d->next;
324 		dev = d->dev;
325 
326 		if (selected_dev) {
327 			netdev_for_each_lower_dev(selected_dev, lower, iter) {
328 				if (dev == lower) {
329 					bring_down = false;
330 					break;
331 				}
332 			}
333 		}
334 		if (bring_down) {
335 			pr_debug("IP-Config: Downing %s\n", dev->name);
336 			dev_change_flags(dev, d->flags, NULL);
337 		}
338 		kfree(d);
339 	}
340 	rtnl_unlock();
341 }
342 
343 /*
344  *	Interface to various network functions.
345  */
346 
347 static inline void
348 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
349 {
350 	sin->sin_family = AF_INET;
351 	sin->sin_addr.s_addr = addr;
352 	sin->sin_port = port;
353 }
354 
355 /*
356  *	Set up interface addresses and routes.
357  */
358 
359 static int __init ic_setup_if(void)
360 {
361 	struct ifreq ir;
362 	struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
363 	int err;
364 
365 	memset(&ir, 0, sizeof(ir));
366 	strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name);
367 	set_sockaddr(sin, ic_myaddr, 0);
368 	if ((err = devinet_ioctl(&init_net, SIOCSIFADDR, &ir)) < 0) {
369 		pr_err("IP-Config: Unable to set interface address (%d)\n",
370 		       err);
371 		return -1;
372 	}
373 	set_sockaddr(sin, ic_netmask, 0);
374 	if ((err = devinet_ioctl(&init_net, SIOCSIFNETMASK, &ir)) < 0) {
375 		pr_err("IP-Config: Unable to set interface netmask (%d)\n",
376 		       err);
377 		return -1;
378 	}
379 	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
380 	if ((err = devinet_ioctl(&init_net, SIOCSIFBRDADDR, &ir)) < 0) {
381 		pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
382 		       err);
383 		return -1;
384 	}
385 	/* Handle the case where we need non-standard MTU on the boot link (a network
386 	 * using jumbo frames, for instance).  If we can't set the mtu, don't error
387 	 * out, we'll try to muddle along.
388 	 */
389 	if (ic_dev_mtu != 0) {
390 		rtnl_lock();
391 		if ((err = dev_set_mtu(ic_dev->dev, ic_dev_mtu)) < 0)
392 			pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
393 			       ic_dev_mtu, err);
394 		rtnl_unlock();
395 	}
396 	return 0;
397 }
398 
399 static int __init ic_setup_routes(void)
400 {
401 	/* No need to setup device routes, only the default route... */
402 
403 	if (ic_gateway != NONE) {
404 		struct rtentry rm;
405 		int err;
406 
407 		memset(&rm, 0, sizeof(rm));
408 		if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
409 			pr_err("IP-Config: Gateway not on directly connected network\n");
410 			return -1;
411 		}
412 		set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
413 		set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
414 		set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
415 		rm.rt_flags = RTF_UP | RTF_GATEWAY;
416 		if ((err = ip_rt_ioctl(&init_net, SIOCADDRT, &rm)) < 0) {
417 			pr_err("IP-Config: Cannot add default route (%d)\n",
418 			       err);
419 			return -1;
420 		}
421 	}
422 
423 	return 0;
424 }
425 
426 /*
427  *	Fill in default values for all missing parameters.
428  */
429 
430 static int __init ic_defaults(void)
431 {
432 	/*
433 	 *	At this point we have no userspace running so need not
434 	 *	claim locks on system_utsname
435 	 */
436 
437 	if (!ic_host_name_set)
438 		sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
439 
440 	if (root_server_addr == NONE)
441 		root_server_addr = ic_servaddr;
442 
443 	if (ic_netmask == NONE) {
444 		if (IN_CLASSA(ntohl(ic_myaddr)))
445 			ic_netmask = htonl(IN_CLASSA_NET);
446 		else if (IN_CLASSB(ntohl(ic_myaddr)))
447 			ic_netmask = htonl(IN_CLASSB_NET);
448 		else if (IN_CLASSC(ntohl(ic_myaddr)))
449 			ic_netmask = htonl(IN_CLASSC_NET);
450 		else if (IN_CLASSE(ntohl(ic_myaddr)))
451 			ic_netmask = htonl(IN_CLASSE_NET);
452 		else {
453 			pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
454 			       &ic_myaddr);
455 			return -1;
456 		}
457 		pr_notice("IP-Config: Guessing netmask %pI4\n",
458 			  &ic_netmask);
459 	}
460 
461 	return 0;
462 }
463 
464 /*
465  *	RARP support.
466  */
467 
468 #ifdef IPCONFIG_RARP
469 
470 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
471 
472 static struct packet_type rarp_packet_type __initdata = {
473 	.type =	cpu_to_be16(ETH_P_RARP),
474 	.func =	ic_rarp_recv,
475 };
476 
477 static inline void __init ic_rarp_init(void)
478 {
479 	dev_add_pack(&rarp_packet_type);
480 }
481 
482 static inline void __init ic_rarp_cleanup(void)
483 {
484 	dev_remove_pack(&rarp_packet_type);
485 }
486 
487 /*
488  *  Process received RARP packet.
489  */
490 static int __init
491 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
492 {
493 	struct arphdr *rarp;
494 	unsigned char *rarp_ptr;
495 	__be32 sip, tip;
496 	unsigned char *tha;		/* t for "target" */
497 	struct ic_device *d;
498 
499 	if (!net_eq(dev_net(dev), &init_net))
500 		goto drop;
501 
502 	skb = skb_share_check(skb, GFP_ATOMIC);
503 	if (!skb)
504 		return NET_RX_DROP;
505 
506 	if (!pskb_may_pull(skb, sizeof(struct arphdr)))
507 		goto drop;
508 
509 	/* Basic sanity checks can be done without the lock.  */
510 	rarp = (struct arphdr *)skb_transport_header(skb);
511 
512 	/* If this test doesn't pass, it's not IP, or we should
513 	 * ignore it anyway.
514 	 */
515 	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
516 		goto drop;
517 
518 	/* If it's not a RARP reply, delete it. */
519 	if (rarp->ar_op != htons(ARPOP_RREPLY))
520 		goto drop;
521 
522 	/* If it's not Ethernet, delete it. */
523 	if (rarp->ar_pro != htons(ETH_P_IP))
524 		goto drop;
525 
526 	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
527 		goto drop;
528 
529 	/* OK, it is all there and looks valid, process... */
530 	rarp = (struct arphdr *)skb_transport_header(skb);
531 	rarp_ptr = (unsigned char *) (rarp + 1);
532 
533 	/* One reply at a time, please. */
534 	spin_lock(&ic_recv_lock);
535 
536 	/* If we already have a reply, just drop the packet */
537 	if (ic_got_reply)
538 		goto drop_unlock;
539 
540 	/* Find the ic_device that the packet arrived on */
541 	d = ic_first_dev;
542 	while (d && d->dev != dev)
543 		d = d->next;
544 	if (!d)
545 		goto drop_unlock;	/* should never happen */
546 
547 	/* Extract variable-width fields */
548 	rarp_ptr += dev->addr_len;
549 	memcpy(&sip, rarp_ptr, 4);
550 	rarp_ptr += 4;
551 	tha = rarp_ptr;
552 	rarp_ptr += dev->addr_len;
553 	memcpy(&tip, rarp_ptr, 4);
554 
555 	/* Discard packets which are not meant for us. */
556 	if (memcmp(tha, dev->dev_addr, dev->addr_len))
557 		goto drop_unlock;
558 
559 	/* Discard packets which are not from specified server. */
560 	if (ic_servaddr != NONE && ic_servaddr != sip)
561 		goto drop_unlock;
562 
563 	/* We have a winner! */
564 	ic_dev = d;
565 	if (ic_myaddr == NONE)
566 		ic_myaddr = tip;
567 	ic_servaddr = sip;
568 	ic_addrservaddr = sip;
569 	ic_got_reply = IC_RARP;
570 
571 drop_unlock:
572 	/* Show's over.  Nothing to see here.  */
573 	spin_unlock(&ic_recv_lock);
574 
575 drop:
576 	/* Throw the packet out. */
577 	kfree_skb(skb);
578 	return 0;
579 }
580 
581 
582 /*
583  *  Send RARP request packet over a single interface.
584  */
585 static void __init ic_rarp_send_if(struct ic_device *d)
586 {
587 	struct net_device *dev = d->dev;
588 	arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
589 		 dev->dev_addr, dev->dev_addr);
590 }
591 #endif
592 
593 /*
594  *  Predefine Nameservers
595  */
596 static inline void __init ic_nameservers_predef(void)
597 {
598 	int i;
599 
600 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
601 		ic_nameservers[i] = NONE;
602 }
603 
604 /* Predefine NTP servers */
605 static inline void __init ic_ntp_servers_predef(void)
606 {
607 	int i;
608 
609 	for (i = 0; i < CONF_NTP_SERVERS_MAX; i++)
610 		ic_ntp_servers[i] = NONE;
611 }
612 
613 /*
614  *	DHCP/BOOTP support.
615  */
616 
617 #ifdef IPCONFIG_BOOTP
618 
619 struct bootp_pkt {		/* BOOTP packet format */
620 	struct iphdr iph;	/* IP header */
621 	struct udphdr udph;	/* UDP header */
622 	u8 op;			/* 1=request, 2=reply */
623 	u8 htype;		/* HW address type */
624 	u8 hlen;		/* HW address length */
625 	u8 hops;		/* Used only by gateways */
626 	__be32 xid;		/* Transaction ID */
627 	__be16 secs;		/* Seconds since we started */
628 	__be16 flags;		/* Just what it says */
629 	__be32 client_ip;		/* Client's IP address if known */
630 	__be32 your_ip;		/* Assigned IP address */
631 	__be32 server_ip;		/* (Next, e.g. NFS) Server's IP address */
632 	__be32 relay_ip;		/* IP address of BOOTP relay */
633 	u8 hw_addr[16];		/* Client's HW address */
634 	u8 serv_name[64];	/* Server host name */
635 	u8 boot_file[128];	/* Name of boot file */
636 	u8 exten[312];		/* DHCP options / BOOTP vendor extensions */
637 };
638 
639 /* packet ops */
640 #define BOOTP_REQUEST	1
641 #define BOOTP_REPLY	2
642 
643 /* DHCP message types */
644 #define DHCPDISCOVER	1
645 #define DHCPOFFER	2
646 #define DHCPREQUEST	3
647 #define DHCPDECLINE	4
648 #define DHCPACK		5
649 #define DHCPNAK		6
650 #define DHCPRELEASE	7
651 #define DHCPINFORM	8
652 
653 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
654 
655 static struct packet_type bootp_packet_type __initdata = {
656 	.type =	cpu_to_be16(ETH_P_IP),
657 	.func =	ic_bootp_recv,
658 };
659 
660 /*
661  *  Initialize DHCP/BOOTP extension fields in the request.
662  */
663 
664 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
665 
666 #ifdef IPCONFIG_DHCP
667 
668 static void __init
669 ic_dhcp_init_options(u8 *options, struct ic_device *d)
670 {
671 	u8 mt = ((ic_servaddr == NONE)
672 		 ? DHCPDISCOVER : DHCPREQUEST);
673 	u8 *e = options;
674 	int len;
675 
676 	pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
677 
678 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
679 	e += 4;
680 
681 	*e++ = 53;		/* DHCP message type */
682 	*e++ = 1;
683 	*e++ = mt;
684 
685 	if (mt == DHCPREQUEST) {
686 		*e++ = 54;	/* Server ID (IP address) */
687 		*e++ = 4;
688 		memcpy(e, &ic_servaddr, 4);
689 		e += 4;
690 
691 		*e++ = 50;	/* Requested IP address */
692 		*e++ = 4;
693 		memcpy(e, &ic_myaddr, 4);
694 		e += 4;
695 	}
696 
697 	/* always? */
698 	{
699 		static const u8 ic_req_params[] = {
700 			1,	/* Subnet mask */
701 			3,	/* Default gateway */
702 			6,	/* DNS server */
703 			12,	/* Host name */
704 			15,	/* Domain name */
705 			17,	/* Boot path */
706 			26,	/* MTU */
707 			40,	/* NIS domain name */
708 			42,	/* NTP servers */
709 		};
710 
711 		*e++ = 55;	/* Parameter request list */
712 		*e++ = sizeof(ic_req_params);
713 		memcpy(e, ic_req_params, sizeof(ic_req_params));
714 		e += sizeof(ic_req_params);
715 
716 		if (ic_host_name_set) {
717 			*e++ = 12;	/* host-name */
718 			len = strlen(utsname()->nodename);
719 			*e++ = len;
720 			memcpy(e, utsname()->nodename, len);
721 			e += len;
722 		}
723 		if (*vendor_class_identifier) {
724 			pr_info("DHCP: sending class identifier \"%s\"\n",
725 				vendor_class_identifier);
726 			*e++ = 60;	/* Class-identifier */
727 			len = strlen(vendor_class_identifier);
728 			*e++ = len;
729 			memcpy(e, vendor_class_identifier, len);
730 			e += len;
731 		}
732 		len = strlen(dhcp_client_identifier + 1);
733 		/* the minimum length of identifier is 2, include 1 byte type,
734 		 * and can not be larger than the length of options
735 		 */
736 		if (len >= 1 && len < 312 - (e - options) - 1) {
737 			*e++ = 61;
738 			*e++ = len + 1;
739 			memcpy(e, dhcp_client_identifier, len + 1);
740 			e += len + 1;
741 		}
742 	}
743 
744 	*e++ = 255;	/* End of the list */
745 }
746 
747 #endif /* IPCONFIG_DHCP */
748 
749 static void __init ic_bootp_init_ext(u8 *e)
750 {
751 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
752 	e += 4;
753 	*e++ = 1;		/* Subnet mask request */
754 	*e++ = 4;
755 	e += 4;
756 	*e++ = 3;		/* Default gateway request */
757 	*e++ = 4;
758 	e += 4;
759 #if CONF_NAMESERVERS_MAX > 0
760 	*e++ = 6;		/* (DNS) name server request */
761 	*e++ = 4 * CONF_NAMESERVERS_MAX;
762 	e += 4 * CONF_NAMESERVERS_MAX;
763 #endif
764 	*e++ = 12;		/* Host name request */
765 	*e++ = 32;
766 	e += 32;
767 	*e++ = 40;		/* NIS Domain name request */
768 	*e++ = 32;
769 	e += 32;
770 	*e++ = 17;		/* Boot path */
771 	*e++ = 40;
772 	e += 40;
773 
774 	*e++ = 57;		/* set extension buffer size for reply */
775 	*e++ = 2;
776 	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
777 	*e++ = 150;
778 
779 	*e++ = 255;		/* End of the list */
780 }
781 
782 
783 /*
784  *  Initialize the DHCP/BOOTP mechanism.
785  */
786 static inline void __init ic_bootp_init(void)
787 {
788 	/* Re-initialise all name servers and NTP servers to NONE, in case any
789 	 * were set via the "ip=" or "nfsaddrs=" kernel command line parameters:
790 	 * any IP addresses specified there will already have been decoded but
791 	 * are no longer needed
792 	 */
793 	ic_nameservers_predef();
794 	ic_ntp_servers_predef();
795 
796 	dev_add_pack(&bootp_packet_type);
797 }
798 
799 
800 /*
801  *  DHCP/BOOTP cleanup.
802  */
803 static inline void __init ic_bootp_cleanup(void)
804 {
805 	dev_remove_pack(&bootp_packet_type);
806 }
807 
808 
809 /*
810  *  Send DHCP/BOOTP request to single interface.
811  */
812 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
813 {
814 	struct net_device *dev = d->dev;
815 	struct sk_buff *skb;
816 	struct bootp_pkt *b;
817 	struct iphdr *h;
818 	int hlen = LL_RESERVED_SPACE(dev);
819 	int tlen = dev->needed_tailroom;
820 
821 	/* Allocate packet */
822 	skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
823 			GFP_KERNEL);
824 	if (!skb)
825 		return;
826 	skb_reserve(skb, hlen);
827 	b = skb_put_zero(skb, sizeof(struct bootp_pkt));
828 
829 	/* Construct IP header */
830 	skb_reset_network_header(skb);
831 	h = ip_hdr(skb);
832 	h->version = 4;
833 	h->ihl = 5;
834 	h->tot_len = htons(sizeof(struct bootp_pkt));
835 	h->frag_off = htons(IP_DF);
836 	h->ttl = 64;
837 	h->protocol = IPPROTO_UDP;
838 	h->daddr = htonl(INADDR_BROADCAST);
839 	h->check = ip_fast_csum((unsigned char *) h, h->ihl);
840 
841 	/* Construct UDP header */
842 	b->udph.source = htons(68);
843 	b->udph.dest = htons(67);
844 	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
845 	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
846 
847 	/* Construct DHCP/BOOTP header */
848 	b->op = BOOTP_REQUEST;
849 	if (dev->type < 256) /* check for false types */
850 		b->htype = dev->type;
851 	else if (dev->type == ARPHRD_FDDI)
852 		b->htype = ARPHRD_ETHER;
853 	else {
854 		pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
855 			dev->name);
856 		b->htype = dev->type; /* can cause undefined behavior */
857 	}
858 
859 	/* server_ip and your_ip address are both already zero per RFC2131 */
860 	b->hlen = dev->addr_len;
861 	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
862 	b->secs = htons(jiffies_diff / HZ);
863 	b->xid = d->xid;
864 
865 	/* add DHCP options or BOOTP extensions */
866 #ifdef IPCONFIG_DHCP
867 	if (ic_proto_enabled & IC_USE_DHCP)
868 		ic_dhcp_init_options(b->exten, d);
869 	else
870 #endif
871 		ic_bootp_init_ext(b->exten);
872 
873 	/* Chain packet down the line... */
874 	skb->dev = dev;
875 	skb->protocol = htons(ETH_P_IP);
876 	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
877 			    dev->broadcast, dev->dev_addr, skb->len) < 0) {
878 		kfree_skb(skb);
879 		printk("E");
880 		return;
881 	}
882 
883 	if (dev_queue_xmit(skb) < 0)
884 		printk("E");
885 }
886 
887 
888 /*
889  *  Copy BOOTP-supplied string if not already set.
890  */
891 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
892 {
893 	if (!len)
894 		return 0;
895 	if (len > max-1)
896 		len = max-1;
897 	memcpy(dest, src, len);
898 	dest[len] = '\0';
899 	return 1;
900 }
901 
902 
903 /*
904  *  Process BOOTP extensions.
905  */
906 static void __init ic_do_bootp_ext(u8 *ext)
907 {
908 	u8 servers;
909 	int i;
910 	__be16 mtu;
911 
912 	u8 *c;
913 
914 	pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
915 	for (c=ext+2; c<ext+2+ext[1]; c++)
916 		pr_debug(" %02x", *c);
917 	pr_debug("\n");
918 
919 	switch (*ext++) {
920 	case 1:		/* Subnet mask */
921 		if (ic_netmask == NONE)
922 			memcpy(&ic_netmask, ext+1, 4);
923 		break;
924 	case 3:		/* Default gateway */
925 		if (ic_gateway == NONE)
926 			memcpy(&ic_gateway, ext+1, 4);
927 		break;
928 	case 6:		/* DNS server */
929 		servers= *ext/4;
930 		if (servers > CONF_NAMESERVERS_MAX)
931 			servers = CONF_NAMESERVERS_MAX;
932 		for (i = 0; i < servers; i++) {
933 			if (ic_nameservers[i] == NONE)
934 				memcpy(&ic_nameservers[i], ext+1+4*i, 4);
935 		}
936 		break;
937 	case 12:	/* Host name */
938 		ic_bootp_string(utsname()->nodename, ext+1, *ext,
939 				__NEW_UTS_LEN);
940 		ic_host_name_set = 1;
941 		break;
942 	case 15:	/* Domain name (DNS) */
943 		ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
944 		break;
945 	case 17:	/* Root path */
946 		if (!root_server_path[0])
947 			ic_bootp_string(root_server_path, ext+1, *ext,
948 					sizeof(root_server_path));
949 		break;
950 	case 26:	/* Interface MTU */
951 		memcpy(&mtu, ext+1, sizeof(mtu));
952 		ic_dev_mtu = ntohs(mtu);
953 		break;
954 	case 40:	/* NIS Domain name (_not_ DNS) */
955 		ic_bootp_string(utsname()->domainname, ext+1, *ext,
956 				__NEW_UTS_LEN);
957 		break;
958 	case 42:	/* NTP servers */
959 		servers = *ext / 4;
960 		if (servers > CONF_NTP_SERVERS_MAX)
961 			servers = CONF_NTP_SERVERS_MAX;
962 		for (i = 0; i < servers; i++) {
963 			if (ic_ntp_servers[i] == NONE)
964 				memcpy(&ic_ntp_servers[i], ext+1+4*i, 4);
965 		}
966 		break;
967 	}
968 }
969 
970 
971 /*
972  *  Receive BOOTP reply.
973  */
974 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
975 {
976 	struct bootp_pkt *b;
977 	struct iphdr *h;
978 	struct ic_device *d;
979 	int len, ext_len;
980 
981 	if (!net_eq(dev_net(dev), &init_net))
982 		goto drop;
983 
984 	/* Perform verifications before taking the lock.  */
985 	if (skb->pkt_type == PACKET_OTHERHOST)
986 		goto drop;
987 
988 	skb = skb_share_check(skb, GFP_ATOMIC);
989 	if (!skb)
990 		return NET_RX_DROP;
991 
992 	if (!pskb_may_pull(skb,
993 			   sizeof(struct iphdr) +
994 			   sizeof(struct udphdr)))
995 		goto drop;
996 
997 	b = (struct bootp_pkt *)skb_network_header(skb);
998 	h = &b->iph;
999 
1000 	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
1001 		goto drop;
1002 
1003 	/* Fragments are not supported */
1004 	if (ip_is_fragment(h)) {
1005 		net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
1006 		goto drop;
1007 	}
1008 
1009 	if (skb->len < ntohs(h->tot_len))
1010 		goto drop;
1011 
1012 	if (ip_fast_csum((char *) h, h->ihl))
1013 		goto drop;
1014 
1015 	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
1016 		goto drop;
1017 
1018 	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
1019 		goto drop;
1020 
1021 	len = ntohs(b->udph.len) - sizeof(struct udphdr);
1022 	ext_len = len - (sizeof(*b) -
1023 			 sizeof(struct iphdr) -
1024 			 sizeof(struct udphdr) -
1025 			 sizeof(b->exten));
1026 	if (ext_len < 0)
1027 		goto drop;
1028 
1029 	/* Ok the front looks good, make sure we can get at the rest.  */
1030 	if (!pskb_may_pull(skb, skb->len))
1031 		goto drop;
1032 
1033 	b = (struct bootp_pkt *)skb_network_header(skb);
1034 	h = &b->iph;
1035 
1036 	/* One reply at a time, please. */
1037 	spin_lock(&ic_recv_lock);
1038 
1039 	/* If we already have a reply, just drop the packet */
1040 	if (ic_got_reply)
1041 		goto drop_unlock;
1042 
1043 	/* Find the ic_device that the packet arrived on */
1044 	d = ic_first_dev;
1045 	while (d && d->dev != dev)
1046 		d = d->next;
1047 	if (!d)
1048 		goto drop_unlock;  /* should never happen */
1049 
1050 	/* Is it a reply to our BOOTP request? */
1051 	if (b->op != BOOTP_REPLY ||
1052 	    b->xid != d->xid) {
1053 		net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1054 				    d->dev->name, b->op, b->xid);
1055 		goto drop_unlock;
1056 	}
1057 
1058 	/* Parse extensions */
1059 	if (ext_len >= 4 &&
1060 	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1061 		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1062 		u8 *ext;
1063 
1064 #ifdef IPCONFIG_DHCP
1065 		if (ic_proto_enabled & IC_USE_DHCP) {
1066 			__be32 server_id = NONE;
1067 			int mt = 0;
1068 
1069 			ext = &b->exten[4];
1070 			while (ext < end && *ext != 0xff) {
1071 				u8 *opt = ext++;
1072 				if (*opt == 0)	/* Padding */
1073 					continue;
1074 				ext += *ext + 1;
1075 				if (ext >= end)
1076 					break;
1077 				switch (*opt) {
1078 				case 53:	/* Message type */
1079 					if (opt[1])
1080 						mt = opt[2];
1081 					break;
1082 				case 54:	/* Server ID (IP address) */
1083 					if (opt[1] >= 4)
1084 						memcpy(&server_id, opt + 2, 4);
1085 					break;
1086 				}
1087 			}
1088 
1089 			pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1090 
1091 			switch (mt) {
1092 			case DHCPOFFER:
1093 				/* While in the process of accepting one offer,
1094 				 * ignore all others.
1095 				 */
1096 				if (ic_myaddr != NONE)
1097 					goto drop_unlock;
1098 
1099 				/* Let's accept that offer. */
1100 				ic_myaddr = b->your_ip;
1101 				ic_servaddr = server_id;
1102 				pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1103 					 &ic_myaddr, &b->iph.saddr);
1104 				/* The DHCP indicated server address takes
1105 				 * precedence over the bootp header one if
1106 				 * they are different.
1107 				 */
1108 				if ((server_id != NONE) &&
1109 				    (b->server_ip != server_id))
1110 					b->server_ip = ic_servaddr;
1111 				break;
1112 
1113 			case DHCPACK:
1114 				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1115 					goto drop_unlock;
1116 
1117 				/* Yeah! */
1118 				break;
1119 
1120 			default:
1121 				/* Urque.  Forget it*/
1122 				ic_myaddr = NONE;
1123 				ic_servaddr = NONE;
1124 				goto drop_unlock;
1125 			}
1126 
1127 			ic_dhcp_msgtype = mt;
1128 
1129 		}
1130 #endif /* IPCONFIG_DHCP */
1131 
1132 		ext = &b->exten[4];
1133 		while (ext < end && *ext != 0xff) {
1134 			u8 *opt = ext++;
1135 			if (*opt == 0)	/* Padding */
1136 				continue;
1137 			ext += *ext + 1;
1138 			if (ext < end)
1139 				ic_do_bootp_ext(opt);
1140 		}
1141 	}
1142 
1143 	/* We have a winner! */
1144 	ic_dev = d;
1145 	ic_myaddr = b->your_ip;
1146 	ic_servaddr = b->server_ip;
1147 	ic_addrservaddr = b->iph.saddr;
1148 	if (ic_gateway == NONE && b->relay_ip)
1149 		ic_gateway = b->relay_ip;
1150 	if (ic_nameservers[0] == NONE)
1151 		ic_nameservers[0] = ic_servaddr;
1152 	ic_got_reply = IC_BOOTP;
1153 
1154 drop_unlock:
1155 	/* Show's over.  Nothing to see here.  */
1156 	spin_unlock(&ic_recv_lock);
1157 
1158 drop:
1159 	/* Throw the packet out. */
1160 	kfree_skb(skb);
1161 
1162 	return 0;
1163 }
1164 
1165 
1166 #endif
1167 
1168 
1169 /*
1170  *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
1171  */
1172 
1173 #ifdef IPCONFIG_DYNAMIC
1174 
1175 static int __init ic_dynamic(void)
1176 {
1177 	int retries;
1178 	struct ic_device *d;
1179 	unsigned long start_jiffies, timeout, jiff;
1180 	int do_bootp = ic_proto_have_if & IC_BOOTP;
1181 	int do_rarp = ic_proto_have_if & IC_RARP;
1182 
1183 	/*
1184 	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1185 	 * This routine gets only called when some pieces of information
1186 	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1187 	 */
1188 	if (!ic_proto_enabled) {
1189 		pr_err("IP-Config: Incomplete network configuration information\n");
1190 		return -1;
1191 	}
1192 
1193 #ifdef IPCONFIG_BOOTP
1194 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1195 		pr_err("DHCP/BOOTP: No suitable device found\n");
1196 #endif
1197 #ifdef IPCONFIG_RARP
1198 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1199 		pr_err("RARP: No suitable device found\n");
1200 #endif
1201 
1202 	if (!ic_proto_have_if)
1203 		/* Error message already printed */
1204 		return -1;
1205 
1206 	/*
1207 	 * Setup protocols
1208 	 */
1209 #ifdef IPCONFIG_BOOTP
1210 	if (do_bootp)
1211 		ic_bootp_init();
1212 #endif
1213 #ifdef IPCONFIG_RARP
1214 	if (do_rarp)
1215 		ic_rarp_init();
1216 #endif
1217 
1218 	/*
1219 	 * Send requests and wait, until we get an answer. This loop
1220 	 * seems to be a terrible waste of CPU time, but actually there is
1221 	 * only one process running at all, so we don't need to use any
1222 	 * scheduler functions.
1223 	 * [Actually we could now, but the nothing else running note still
1224 	 *  applies.. - AC]
1225 	 */
1226 	pr_notice("Sending %s%s%s requests .",
1227 		  do_bootp
1228 		  ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1229 		  (do_bootp && do_rarp) ? " and " : "",
1230 		  do_rarp ? "RARP" : "");
1231 
1232 	start_jiffies = jiffies;
1233 	d = ic_first_dev;
1234 	retries = CONF_SEND_RETRIES;
1235 	get_random_bytes(&timeout, sizeof(timeout));
1236 	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1237 	for (;;) {
1238 #ifdef IPCONFIG_BOOTP
1239 		if (do_bootp && (d->able & IC_BOOTP))
1240 			ic_bootp_send_if(d, jiffies - start_jiffies);
1241 #endif
1242 #ifdef IPCONFIG_RARP
1243 		if (do_rarp && (d->able & IC_RARP))
1244 			ic_rarp_send_if(d);
1245 #endif
1246 
1247 		if (!d->next) {
1248 			jiff = jiffies + timeout;
1249 			while (time_before(jiffies, jiff) && !ic_got_reply)
1250 				schedule_timeout_uninterruptible(1);
1251 		}
1252 #ifdef IPCONFIG_DHCP
1253 		/* DHCP isn't done until we get a DHCPACK. */
1254 		if ((ic_got_reply & IC_BOOTP) &&
1255 		    (ic_proto_enabled & IC_USE_DHCP) &&
1256 		    ic_dhcp_msgtype != DHCPACK) {
1257 			ic_got_reply = 0;
1258 			/* continue on device that got the reply */
1259 			d = ic_dev;
1260 			pr_cont(",");
1261 			continue;
1262 		}
1263 #endif /* IPCONFIG_DHCP */
1264 
1265 		if (ic_got_reply) {
1266 			pr_cont(" OK\n");
1267 			break;
1268 		}
1269 
1270 		if ((d = d->next))
1271 			continue;
1272 
1273 		if (! --retries) {
1274 			pr_cont(" timed out!\n");
1275 			break;
1276 		}
1277 
1278 		d = ic_first_dev;
1279 
1280 		timeout = timeout CONF_TIMEOUT_MULT;
1281 		if (timeout > CONF_TIMEOUT_MAX)
1282 			timeout = CONF_TIMEOUT_MAX;
1283 
1284 		pr_cont(".");
1285 	}
1286 
1287 #ifdef IPCONFIG_BOOTP
1288 	if (do_bootp)
1289 		ic_bootp_cleanup();
1290 #endif
1291 #ifdef IPCONFIG_RARP
1292 	if (do_rarp)
1293 		ic_rarp_cleanup();
1294 #endif
1295 
1296 	if (!ic_got_reply) {
1297 		ic_myaddr = NONE;
1298 		return -1;
1299 	}
1300 
1301 	pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1302 		((ic_got_reply & IC_RARP) ? "RARP"
1303 		: (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1304 		&ic_addrservaddr, &ic_myaddr);
1305 
1306 	return 0;
1307 }
1308 
1309 #endif /* IPCONFIG_DYNAMIC */
1310 
1311 #ifdef CONFIG_PROC_FS
1312 /* proc_dir_entry for /proc/net/ipconfig */
1313 static struct proc_dir_entry *ipconfig_dir;
1314 
1315 /* Name servers: */
1316 static int pnp_seq_show(struct seq_file *seq, void *v)
1317 {
1318 	int i;
1319 
1320 	if (ic_proto_used & IC_PROTO)
1321 		seq_printf(seq, "#PROTO: %s\n",
1322 			   (ic_proto_used & IC_RARP) ? "RARP"
1323 			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1324 	else
1325 		seq_puts(seq, "#MANUAL\n");
1326 
1327 	if (ic_domain[0])
1328 		seq_printf(seq,
1329 			   "domain %s\n", ic_domain);
1330 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1331 		if (ic_nameservers[i] != NONE)
1332 			seq_printf(seq, "nameserver %pI4\n",
1333 				   &ic_nameservers[i]);
1334 	}
1335 	if (ic_servaddr != NONE)
1336 		seq_printf(seq, "bootserver %pI4\n",
1337 			   &ic_servaddr);
1338 	return 0;
1339 }
1340 
1341 /* Create the /proc/net/ipconfig directory */
1342 static int __init ipconfig_proc_net_init(void)
1343 {
1344 	ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net);
1345 	if (!ipconfig_dir)
1346 		return -ENOMEM;
1347 
1348 	return 0;
1349 }
1350 
1351 /* Create a new file under /proc/net/ipconfig */
1352 static int ipconfig_proc_net_create(const char *name,
1353 				    const struct proc_ops *proc_ops)
1354 {
1355 	char *pname;
1356 	struct proc_dir_entry *p;
1357 
1358 	if (!ipconfig_dir)
1359 		return -ENOMEM;
1360 
1361 	pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name);
1362 	if (!pname)
1363 		return -ENOMEM;
1364 
1365 	p = proc_create(pname, 0444, init_net.proc_net, proc_ops);
1366 	kfree(pname);
1367 	if (!p)
1368 		return -ENOMEM;
1369 
1370 	return 0;
1371 }
1372 
1373 /* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */
1374 static int ntp_servers_show(struct seq_file *seq, void *v)
1375 {
1376 	int i;
1377 
1378 	for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1379 		if (ic_ntp_servers[i] != NONE)
1380 			seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]);
1381 	}
1382 	return 0;
1383 }
1384 DEFINE_PROC_SHOW_ATTRIBUTE(ntp_servers);
1385 #endif /* CONFIG_PROC_FS */
1386 
1387 /*
1388  *  Extract IP address from the parameter string if needed. Note that we
1389  *  need to have root_server_addr set _before_ IPConfig gets called as it
1390  *  can override it.
1391  */
1392 __be32 __init root_nfs_parse_addr(char *name)
1393 {
1394 	__be32 addr;
1395 	int octets = 0;
1396 	char *cp, *cq;
1397 
1398 	cp = cq = name;
1399 	while (octets < 4) {
1400 		while (*cp >= '0' && *cp <= '9')
1401 			cp++;
1402 		if (cp == cq || cp - cq > 3)
1403 			break;
1404 		if (*cp == '.' || octets == 3)
1405 			octets++;
1406 		if (octets < 4)
1407 			cp++;
1408 		cq = cp;
1409 	}
1410 	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1411 		if (*cp == ':')
1412 			*cp++ = '\0';
1413 		addr = in_aton(name);
1414 		memmove(name, cp, strlen(cp) + 1);
1415 	} else
1416 		addr = NONE;
1417 
1418 	return addr;
1419 }
1420 
1421 #define DEVICE_WAIT_MAX		12 /* 12 seconds */
1422 
1423 static int __init wait_for_devices(void)
1424 {
1425 	int i;
1426 
1427 	for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1428 		struct net_device *dev;
1429 		int found = 0;
1430 
1431 		/* make sure deferred device probes are finished */
1432 		wait_for_device_probe();
1433 
1434 		rtnl_lock();
1435 		for_each_netdev(&init_net, dev) {
1436 			if (ic_is_init_dev(dev)) {
1437 				found = 1;
1438 				break;
1439 			}
1440 		}
1441 		rtnl_unlock();
1442 		if (found)
1443 			return 0;
1444 		ssleep(1);
1445 	}
1446 	return -ENODEV;
1447 }
1448 
1449 /*
1450  *	IP Autoconfig dispatcher.
1451  */
1452 
1453 static int __init ip_auto_config(void)
1454 {
1455 	__be32 addr;
1456 #ifdef IPCONFIG_DYNAMIC
1457 	int retries = CONF_OPEN_RETRIES;
1458 #endif
1459 	int err;
1460 	unsigned int i, count;
1461 
1462 	/* Initialise all name servers and NTP servers to NONE (but only if the
1463 	 * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded,
1464 	 * otherwise we'll overwrite the IP addresses specified there)
1465 	 */
1466 	if (ic_set_manually == 0) {
1467 		ic_nameservers_predef();
1468 		ic_ntp_servers_predef();
1469 	}
1470 
1471 #ifdef CONFIG_PROC_FS
1472 	proc_create_single("pnp", 0444, init_net.proc_net, pnp_seq_show);
1473 
1474 	if (ipconfig_proc_net_init() == 0)
1475 		ipconfig_proc_net_create("ntp_servers", &ntp_servers_proc_ops);
1476 #endif /* CONFIG_PROC_FS */
1477 
1478 	if (!ic_enable)
1479 		return 0;
1480 
1481 	pr_debug("IP-Config: Entered.\n");
1482 #ifdef IPCONFIG_DYNAMIC
1483  try_try_again:
1484 #endif
1485 	/* Wait for devices to appear */
1486 	err = wait_for_devices();
1487 	if (err)
1488 		return err;
1489 
1490 	/* Setup all network devices */
1491 	err = ic_open_devs();
1492 	if (err)
1493 		return err;
1494 
1495 	/* Give drivers a chance to settle */
1496 	msleep(CONF_POST_OPEN);
1497 
1498 	/*
1499 	 * If the config information is insufficient (e.g., our IP address or
1500 	 * IP address of the boot server is missing or we have multiple network
1501 	 * interfaces and no default was set), use BOOTP or RARP to get the
1502 	 * missing values.
1503 	 */
1504 	if (ic_myaddr == NONE ||
1505 #if defined(CONFIG_ROOT_NFS) || defined(CONFIG_CIFS_ROOT)
1506 	    (root_server_addr == NONE &&
1507 	     ic_servaddr == NONE &&
1508 	     (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) ||
1509 #endif
1510 	    ic_first_dev->next) {
1511 #ifdef IPCONFIG_DYNAMIC
1512 		if (ic_dynamic() < 0) {
1513 			ic_close_devs();
1514 
1515 			/*
1516 			 * I don't know why, but sometimes the
1517 			 * eepro100 driver (at least) gets upset and
1518 			 * doesn't work the first time it's opened.
1519 			 * But then if you close it and reopen it, it
1520 			 * works just fine.  So we need to try that at
1521 			 * least once before giving up.
1522 			 *
1523 			 * Also, if the root will be NFS-mounted, we
1524 			 * have nowhere to go if DHCP fails.  So we
1525 			 * just have to keep trying forever.
1526 			 *
1527 			 * 				-- Chip
1528 			 */
1529 #ifdef CONFIG_ROOT_NFS
1530 			if (ROOT_DEV ==  Root_NFS) {
1531 				pr_err("IP-Config: Retrying forever (NFS root)...\n");
1532 				goto try_try_again;
1533 			}
1534 #endif
1535 #ifdef CONFIG_CIFS_ROOT
1536 			if (ROOT_DEV == Root_CIFS) {
1537 				pr_err("IP-Config: Retrying forever (CIFS root)...\n");
1538 				goto try_try_again;
1539 			}
1540 #endif
1541 
1542 			if (--retries) {
1543 				pr_err("IP-Config: Reopening network devices...\n");
1544 				goto try_try_again;
1545 			}
1546 
1547 			/* Oh, well.  At least we tried. */
1548 			pr_err("IP-Config: Auto-configuration of network failed\n");
1549 			return -1;
1550 		}
1551 #else /* !DYNAMIC */
1552 		pr_err("IP-Config: Incomplete network configuration information\n");
1553 		ic_close_devs();
1554 		return -1;
1555 #endif /* IPCONFIG_DYNAMIC */
1556 	} else {
1557 		/* Device selected manually or only one device -> use it */
1558 		ic_dev = ic_first_dev;
1559 	}
1560 
1561 	addr = root_nfs_parse_addr(root_server_path);
1562 	if (root_server_addr == NONE)
1563 		root_server_addr = addr;
1564 
1565 	/*
1566 	 * Use defaults wherever applicable.
1567 	 */
1568 	if (ic_defaults() < 0)
1569 		return -1;
1570 
1571 	/*
1572 	 * Record which protocol was actually used.
1573 	 */
1574 #ifdef IPCONFIG_DYNAMIC
1575 	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1576 #endif
1577 
1578 #ifndef IPCONFIG_SILENT
1579 	/*
1580 	 * Clue in the operator.
1581 	 */
1582 	pr_info("IP-Config: Complete:\n");
1583 
1584 	pr_info("     device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1585 		ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1586 		&ic_myaddr, &ic_netmask, &ic_gateway);
1587 	pr_info("     host=%s, domain=%s, nis-domain=%s\n",
1588 		utsname()->nodename, ic_domain, utsname()->domainname);
1589 	pr_info("     bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1590 		&ic_servaddr, &root_server_addr, root_server_path);
1591 	if (ic_dev_mtu)
1592 		pr_cont(", mtu=%d", ic_dev_mtu);
1593 	/* Name servers (if any): */
1594 	for (i = 0, count = 0; i < CONF_NAMESERVERS_MAX; i++) {
1595 		if (ic_nameservers[i] != NONE) {
1596 			if (i == 0)
1597 				pr_info("     nameserver%u=%pI4",
1598 					i, &ic_nameservers[i]);
1599 			else
1600 				pr_cont(", nameserver%u=%pI4",
1601 					i, &ic_nameservers[i]);
1602 
1603 			count++;
1604 		}
1605 		if ((i + 1 == CONF_NAMESERVERS_MAX) && count > 0)
1606 			pr_cont("\n");
1607 	}
1608 	/* NTP servers (if any): */
1609 	for (i = 0, count = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1610 		if (ic_ntp_servers[i] != NONE) {
1611 			if (i == 0)
1612 				pr_info("     ntpserver%u=%pI4",
1613 					i, &ic_ntp_servers[i]);
1614 			else
1615 				pr_cont(", ntpserver%u=%pI4",
1616 					i, &ic_ntp_servers[i]);
1617 
1618 			count++;
1619 		}
1620 		if ((i + 1 == CONF_NTP_SERVERS_MAX) && count > 0)
1621 			pr_cont("\n");
1622 	}
1623 #endif /* !SILENT */
1624 
1625 	/*
1626 	 * Close all network devices except the device we've
1627 	 * autoconfigured and set up routes.
1628 	 */
1629 	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1630 		err = -1;
1631 	else
1632 		err = 0;
1633 
1634 	ic_close_devs();
1635 
1636 	return err;
1637 }
1638 
1639 late_initcall(ip_auto_config);
1640 
1641 
1642 /*
1643  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1644  *  command line parameter.  See Documentation/admin-guide/nfs/nfsroot.rst.
1645  */
1646 static int __init ic_proto_name(char *name)
1647 {
1648 	if (!strcmp(name, "on") || !strcmp(name, "any")) {
1649 		return 1;
1650 	}
1651 	if (!strcmp(name, "off") || !strcmp(name, "none")) {
1652 		return 0;
1653 	}
1654 #ifdef CONFIG_IP_PNP_DHCP
1655 	else if (!strncmp(name, "dhcp", 4)) {
1656 		char *client_id;
1657 
1658 		ic_proto_enabled &= ~IC_RARP;
1659 		client_id = strstr(name, "dhcp,");
1660 		if (client_id) {
1661 			char *v;
1662 
1663 			client_id = client_id + 5;
1664 			v = strchr(client_id, ',');
1665 			if (!v)
1666 				return 1;
1667 			*v = 0;
1668 			if (kstrtou8(client_id, 0, dhcp_client_identifier))
1669 				pr_debug("DHCP: Invalid client identifier type\n");
1670 			strncpy(dhcp_client_identifier + 1, v + 1, 251);
1671 			*v = ',';
1672 		}
1673 		return 1;
1674 	}
1675 #endif
1676 #ifdef CONFIG_IP_PNP_BOOTP
1677 	else if (!strcmp(name, "bootp")) {
1678 		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1679 		return 1;
1680 	}
1681 #endif
1682 #ifdef CONFIG_IP_PNP_RARP
1683 	else if (!strcmp(name, "rarp")) {
1684 		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1685 		return 1;
1686 	}
1687 #endif
1688 #ifdef IPCONFIG_DYNAMIC
1689 	else if (!strcmp(name, "both")) {
1690 		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1691 		return 1;
1692 	}
1693 #endif
1694 	return 0;
1695 }
1696 
1697 static int __init ip_auto_config_setup(char *addrs)
1698 {
1699 	char *cp, *ip, *dp;
1700 	int num = 0;
1701 
1702 	ic_set_manually = 1;
1703 	ic_enable = 1;
1704 
1705 	/*
1706 	 * If any dhcp, bootp etc options are set, leave autoconfig on
1707 	 * and skip the below static IP processing.
1708 	 */
1709 	if (ic_proto_name(addrs))
1710 		return 1;
1711 
1712 	/* If no static IP is given, turn off autoconfig and bail.  */
1713 	if (*addrs == 0 ||
1714 	    strcmp(addrs, "off") == 0 ||
1715 	    strcmp(addrs, "none") == 0) {
1716 		ic_enable = 0;
1717 		return 1;
1718 	}
1719 
1720 	/* Initialise all name servers and NTP servers to NONE */
1721 	ic_nameservers_predef();
1722 	ic_ntp_servers_predef();
1723 
1724 	/* Parse string for static IP assignment.  */
1725 	ip = addrs;
1726 	while (ip && *ip) {
1727 		if ((cp = strchr(ip, ':')))
1728 			*cp++ = '\0';
1729 		if (strlen(ip) > 0) {
1730 			pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1731 			switch (num) {
1732 			case 0:
1733 				if ((ic_myaddr = in_aton(ip)) == ANY)
1734 					ic_myaddr = NONE;
1735 				break;
1736 			case 1:
1737 				if ((ic_servaddr = in_aton(ip)) == ANY)
1738 					ic_servaddr = NONE;
1739 				break;
1740 			case 2:
1741 				if ((ic_gateway = in_aton(ip)) == ANY)
1742 					ic_gateway = NONE;
1743 				break;
1744 			case 3:
1745 				if ((ic_netmask = in_aton(ip)) == ANY)
1746 					ic_netmask = NONE;
1747 				break;
1748 			case 4:
1749 				if ((dp = strchr(ip, '.'))) {
1750 					*dp++ = '\0';
1751 					strlcpy(utsname()->domainname, dp,
1752 						sizeof(utsname()->domainname));
1753 				}
1754 				strlcpy(utsname()->nodename, ip,
1755 					sizeof(utsname()->nodename));
1756 				ic_host_name_set = 1;
1757 				break;
1758 			case 5:
1759 				strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1760 				break;
1761 			case 6:
1762 				if (ic_proto_name(ip) == 0 &&
1763 				    ic_myaddr == NONE) {
1764 					ic_enable = 0;
1765 				}
1766 				break;
1767 			case 7:
1768 				if (CONF_NAMESERVERS_MAX >= 1) {
1769 					ic_nameservers[0] = in_aton(ip);
1770 					if (ic_nameservers[0] == ANY)
1771 						ic_nameservers[0] = NONE;
1772 				}
1773 				break;
1774 			case 8:
1775 				if (CONF_NAMESERVERS_MAX >= 2) {
1776 					ic_nameservers[1] = in_aton(ip);
1777 					if (ic_nameservers[1] == ANY)
1778 						ic_nameservers[1] = NONE;
1779 				}
1780 				break;
1781 			case 9:
1782 				if (CONF_NTP_SERVERS_MAX >= 1) {
1783 					ic_ntp_servers[0] = in_aton(ip);
1784 					if (ic_ntp_servers[0] == ANY)
1785 						ic_ntp_servers[0] = NONE;
1786 				}
1787 				break;
1788 			}
1789 		}
1790 		ip = cp;
1791 		num++;
1792 	}
1793 
1794 	return 1;
1795 }
1796 __setup("ip=", ip_auto_config_setup);
1797 
1798 static int __init nfsaddrs_config_setup(char *addrs)
1799 {
1800 	return ip_auto_config_setup(addrs);
1801 }
1802 __setup("nfsaddrs=", nfsaddrs_config_setup);
1803 
1804 static int __init vendor_class_identifier_setup(char *addrs)
1805 {
1806 	if (strlcpy(vendor_class_identifier, addrs,
1807 		    sizeof(vendor_class_identifier))
1808 	    >= sizeof(vendor_class_identifier))
1809 		pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1810 			vendor_class_identifier);
1811 	return 1;
1812 }
1813 __setup("dhcpclass=", vendor_class_identifier_setup);
1814 
1815 static int __init set_carrier_timeout(char *str)
1816 {
1817 	ssize_t ret;
1818 
1819 	if (!str)
1820 		return 0;
1821 
1822 	ret = kstrtouint(str, 0, &carrier_timeout);
1823 	if (ret)
1824 		return 0;
1825 
1826 	return 1;
1827 }
1828 __setup("carrier_timeout=", set_carrier_timeout);
1829