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 */
103static 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 */
113int ic_set_manually __initdata = 0; /* IPconfig parameters set manually */
114
115static int ic_enable __initdata; /* IP config enabled? */
116
117/* Protocol choice */
118int 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
130static int ic_host_name_set __initdata; /* Host name set by us? */
131
132__be32 ic_myaddr = NONE; /* My IP address */
133static __be32 ic_netmask = NONE; /* Netmask for local subnet */
134__be32 ic_gateway = NONE; /* Gateway IP address */
135
136#ifdef IPCONFIG_DYNAMIC
137static __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 */
143u8 root_server_path[256] = { 0, }; /* Path to mount as root */
144
145/* vendor class identifier */
146static char vendor_class_identifier[253] __initdata;
147
148#if defined(CONFIG_IP_PNP_DHCP)
149static char dhcp_client_identifier[253] __initdata;
150#endif
151
152/* Persistent data: */
153
154#ifdef IPCONFIG_DYNAMIC
155static int ic_proto_used; /* Protocol used, if any */
156#else
157#define ic_proto_used 0
158#endif
159static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
160static __be32 ic_ntp_servers[CONF_NTP_SERVERS_MAX]; /* NTP server IP addresses */
161static u8 ic_domain[64]; /* DNS (not NIS) domain name */
162
163/*
164 * Private state.
165 */
166
167/* Name of user-selected boot device */
168static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
169
170/* Protocols supported by available interfaces */
171static int ic_proto_have_if __initdata;
172
173/* MTU for boot device */
174static int ic_dev_mtu __initdata;
175
176#ifdef IPCONFIG_DYNAMIC
177static DEFINE_SPINLOCK(ic_recv_lock);
178static volatile int ic_got_reply __initdata; /* Proto(s) that replied */
179#endif
180#ifdef IPCONFIG_DHCP
181static int ic_dhcp_msgtype __initdata; /* DHCP msg type received */
182#endif
183
184
185/*
186 * Network devices
187 */
188
189struct ic_device {
190 struct ic_device *next;
191 struct net_device *dev;
192 unsigned short flags;
193 short able;
194 __be32 xid;
195};
196
197static struct ic_device *ic_first_dev __initdata; /* List of open device */
198static struct ic_device *ic_dev __initdata; /* Selected device */
199
200static 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
210static 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, flags: 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, flags: 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(buf: &d->xid, len: sizeof(__be32));
258 else
259 d->xid = 0;
260 ic_proto_have_if |= able;
261 pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n",
262 dev->name, able, d->xid);
263 }
264 }
265 /* Devices with a complex topology like SFP ethernet interfaces needs
266 * the rtnl_lock at init. The carrier wait-loop must therefore run
267 * without holding it.
268 */
269 rtnl_unlock();
270
271 /* no point in waiting if we could not bring up at least one device */
272 if (!ic_first_dev)
273 goto have_carrier;
274
275 /* wait for a carrier on at least one device */
276 start = jiffies;
277 next_msg = start + msecs_to_jiffies(m: 20000);
278 while (time_before(jiffies, start +
279 msecs_to_jiffies(carrier_timeout * 1000))) {
280 int wait, elapsed;
281
282 rtnl_lock();
283 for_each_netdev(&init_net, dev)
284 if (ic_is_init_dev(dev) && netif_carrier_ok(dev)) {
285 rtnl_unlock();
286 goto have_carrier;
287 }
288 rtnl_unlock();
289
290 msleep(msecs: 1);
291
292 if (time_before(jiffies, next_msg))
293 continue;
294
295 elapsed = jiffies_to_msecs(j: jiffies - start);
296 wait = (carrier_timeout * 1000 - elapsed + 500) / 1000;
297 pr_info("Waiting up to %d more seconds for network.\n", wait);
298 next_msg = jiffies + msecs_to_jiffies(m: 20000);
299 }
300have_carrier:
301
302 *last = NULL;
303
304 if (!ic_first_dev) {
305 if (user_dev_name[0])
306 pr_err("IP-Config: Device `%s' not found\n",
307 user_dev_name);
308 else
309 pr_err("IP-Config: No network devices available\n");
310 return -ENODEV;
311 }
312 return 0;
313}
314
315/* Close all network interfaces except the one we've autoconfigured, and its
316 * lowers, in case it's a stacked virtual interface.
317 */
318static void __init ic_close_devs(void)
319{
320 struct net_device *selected_dev = ic_dev ? ic_dev->dev : NULL;
321 struct ic_device *d, *next;
322 struct net_device *dev;
323
324 rtnl_lock();
325 next = ic_first_dev;
326 while ((d = next)) {
327 bool bring_down = (d != ic_dev);
328 struct net_device *lower;
329 struct list_head *iter;
330
331 next = d->next;
332 dev = d->dev;
333
334 if (selected_dev) {
335 netdev_for_each_lower_dev(selected_dev, lower, iter) {
336 if (dev == lower) {
337 bring_down = false;
338 break;
339 }
340 }
341 }
342 if (bring_down) {
343 pr_debug("IP-Config: Downing %s\n", dev->name);
344 dev_change_flags(dev, flags: d->flags, NULL);
345 }
346 kfree(objp: d);
347 }
348 rtnl_unlock();
349}
350
351/*
352 * Interface to various network functions.
353 */
354
355static inline void
356set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
357{
358 sin->sin_family = AF_INET;
359 sin->sin_addr.s_addr = addr;
360 sin->sin_port = port;
361}
362
363/*
364 * Set up interface addresses and routes.
365 */
366
367static int __init ic_setup_if(void)
368{
369 struct ifreq ir;
370 struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
371 int err;
372
373 memset(&ir, 0, sizeof(ir));
374 strcpy(p: ir.ifr_ifrn.ifrn_name, q: ic_dev->dev->name);
375 set_sockaddr(sin, addr: ic_myaddr, port: 0);
376 if ((err = devinet_ioctl(net: &init_net, SIOCSIFADDR, &ir)) < 0) {
377 pr_err("IP-Config: Unable to set interface address (%d)\n",
378 err);
379 return -1;
380 }
381 set_sockaddr(sin, addr: ic_netmask, port: 0);
382 if ((err = devinet_ioctl(net: &init_net, SIOCSIFNETMASK, &ir)) < 0) {
383 pr_err("IP-Config: Unable to set interface netmask (%d)\n",
384 err);
385 return -1;
386 }
387 set_sockaddr(sin, addr: ic_myaddr | ~ic_netmask, port: 0);
388 if ((err = devinet_ioctl(net: &init_net, SIOCSIFBRDADDR, &ir)) < 0) {
389 pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
390 err);
391 return -1;
392 }
393 /* Handle the case where we need non-standard MTU on the boot link (a network
394 * using jumbo frames, for instance). If we can't set the mtu, don't error
395 * out, we'll try to muddle along.
396 */
397 if (ic_dev_mtu != 0) {
398 rtnl_lock();
399 if ((err = dev_set_mtu(ic_dev->dev, ic_dev_mtu)) < 0)
400 pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
401 ic_dev_mtu, err);
402 rtnl_unlock();
403 }
404 return 0;
405}
406
407static int __init ic_setup_routes(void)
408{
409 /* No need to setup device routes, only the default route... */
410
411 if (ic_gateway != NONE) {
412 struct rtentry rm;
413 int err;
414
415 memset(&rm, 0, sizeof(rm));
416 if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
417 pr_err("IP-Config: Gateway not on directly connected network\n");
418 return -1;
419 }
420 set_sockaddr(sin: (struct sockaddr_in *) &rm.rt_dst, addr: 0, port: 0);
421 set_sockaddr(sin: (struct sockaddr_in *) &rm.rt_genmask, addr: 0, port: 0);
422 set_sockaddr(sin: (struct sockaddr_in *) &rm.rt_gateway, addr: ic_gateway, port: 0);
423 rm.rt_flags = RTF_UP | RTF_GATEWAY;
424 if ((err = ip_rt_ioctl(&init_net, SIOCADDRT, rt: &rm)) < 0) {
425 pr_err("IP-Config: Cannot add default route (%d)\n",
426 err);
427 return -1;
428 }
429 }
430
431 return 0;
432}
433
434/*
435 * Fill in default values for all missing parameters.
436 */
437
438static int __init ic_defaults(void)
439{
440 /*
441 * At this point we have no userspace running so need not
442 * claim locks on system_utsname
443 */
444
445 if (!ic_host_name_set)
446 sprintf(buf: init_utsname()->nodename, fmt: "%pI4", &ic_myaddr);
447
448 if (root_server_addr == NONE)
449 root_server_addr = ic_servaddr;
450
451 if (ic_netmask == NONE) {
452 if (IN_CLASSA(ntohl(ic_myaddr)))
453 ic_netmask = htonl(IN_CLASSA_NET);
454 else if (IN_CLASSB(ntohl(ic_myaddr)))
455 ic_netmask = htonl(IN_CLASSB_NET);
456 else if (IN_CLASSC(ntohl(ic_myaddr)))
457 ic_netmask = htonl(IN_CLASSC_NET);
458 else if (IN_CLASSE(ntohl(ic_myaddr)))
459 ic_netmask = htonl(IN_CLASSE_NET);
460 else {
461 pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
462 &ic_myaddr);
463 return -1;
464 }
465 pr_notice("IP-Config: Guessing netmask %pI4\n",
466 &ic_netmask);
467 }
468
469 return 0;
470}
471
472/*
473 * RARP support.
474 */
475
476#ifdef IPCONFIG_RARP
477
478static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
479
480static struct packet_type rarp_packet_type __initdata = {
481 .type = cpu_to_be16(ETH_P_RARP),
482 .func = ic_rarp_recv,
483};
484
485static inline void __init ic_rarp_init(void)
486{
487 dev_add_pack(pt: &rarp_packet_type);
488}
489
490static inline void __init ic_rarp_cleanup(void)
491{
492 dev_remove_pack(pt: &rarp_packet_type);
493}
494
495/*
496 * Process received RARP packet.
497 */
498static int __init
499ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
500{
501 struct arphdr *rarp;
502 unsigned char *rarp_ptr;
503 __be32 sip, tip;
504 unsigned char *tha; /* t for "target" */
505 struct ic_device *d;
506
507 if (!net_eq(net1: dev_net(dev), net2: &init_net))
508 goto drop;
509
510 skb = skb_share_check(skb, GFP_ATOMIC);
511 if (!skb)
512 return NET_RX_DROP;
513
514 if (!pskb_may_pull(skb, len: sizeof(struct arphdr)))
515 goto drop;
516
517 /* Basic sanity checks can be done without the lock. */
518 rarp = (struct arphdr *)skb_transport_header(skb);
519
520 /* If this test doesn't pass, it's not IP, or we should
521 * ignore it anyway.
522 */
523 if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
524 goto drop;
525
526 /* If it's not a RARP reply, delete it. */
527 if (rarp->ar_op != htons(ARPOP_RREPLY))
528 goto drop;
529
530 /* If it's not Ethernet, delete it. */
531 if (rarp->ar_pro != htons(ETH_P_IP))
532 goto drop;
533
534 if (!pskb_may_pull(skb, len: arp_hdr_len(dev)))
535 goto drop;
536
537 /* OK, it is all there and looks valid, process... */
538 rarp = (struct arphdr *)skb_transport_header(skb);
539 rarp_ptr = (unsigned char *) (rarp + 1);
540
541 /* One reply at a time, please. */
542 spin_lock(lock: &ic_recv_lock);
543
544 /* If we already have a reply, just drop the packet */
545 if (ic_got_reply)
546 goto drop_unlock;
547
548 /* Find the ic_device that the packet arrived on */
549 d = ic_first_dev;
550 while (d && d->dev != dev)
551 d = d->next;
552 if (!d)
553 goto drop_unlock; /* should never happen */
554
555 /* Extract variable-width fields */
556 rarp_ptr += dev->addr_len;
557 memcpy(&sip, rarp_ptr, 4);
558 rarp_ptr += 4;
559 tha = rarp_ptr;
560 rarp_ptr += dev->addr_len;
561 memcpy(&tip, rarp_ptr, 4);
562
563 /* Discard packets which are not meant for us. */
564 if (memcmp(p: tha, q: dev->dev_addr, size: dev->addr_len))
565 goto drop_unlock;
566
567 /* Discard packets which are not from specified server. */
568 if (ic_servaddr != NONE && ic_servaddr != sip)
569 goto drop_unlock;
570
571 /* We have a winner! */
572 ic_dev = d;
573 if (ic_myaddr == NONE)
574 ic_myaddr = tip;
575 ic_servaddr = sip;
576 ic_addrservaddr = sip;
577 ic_got_reply = IC_RARP;
578
579drop_unlock:
580 /* Show's over. Nothing to see here. */
581 spin_unlock(lock: &ic_recv_lock);
582
583drop:
584 /* Throw the packet out. */
585 kfree_skb(skb);
586 return 0;
587}
588
589
590/*
591 * Send RARP request packet over a single interface.
592 */
593static void __init ic_rarp_send_if(struct ic_device *d)
594{
595 struct net_device *dev = d->dev;
596 arp_send(ARPOP_RREQUEST, ETH_P_RARP, dest_ip: 0, dev, src_ip: 0, NULL,
597 src_hw: dev->dev_addr, th: dev->dev_addr);
598}
599#endif
600
601/*
602 * Predefine Nameservers
603 */
604static inline void __init ic_nameservers_predef(void)
605{
606 int i;
607
608 for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
609 ic_nameservers[i] = NONE;
610}
611
612/* Predefine NTP servers */
613static inline void __init ic_ntp_servers_predef(void)
614{
615 int i;
616
617 for (i = 0; i < CONF_NTP_SERVERS_MAX; i++)
618 ic_ntp_servers[i] = NONE;
619}
620
621/*
622 * DHCP/BOOTP support.
623 */
624
625#ifdef IPCONFIG_BOOTP
626
627struct bootp_pkt { /* BOOTP packet format */
628 struct iphdr iph; /* IP header */
629 struct udphdr udph; /* UDP header */
630 u8 op; /* 1=request, 2=reply */
631 u8 htype; /* HW address type */
632 u8 hlen; /* HW address length */
633 u8 hops; /* Used only by gateways */
634 __be32 xid; /* Transaction ID */
635 __be16 secs; /* Seconds since we started */
636 __be16 flags; /* Just what it says */
637 __be32 client_ip; /* Client's IP address if known */
638 __be32 your_ip; /* Assigned IP address */
639 __be32 server_ip; /* (Next, e.g. NFS) Server's IP address */
640 __be32 relay_ip; /* IP address of BOOTP relay */
641 u8 hw_addr[16]; /* Client's HW address */
642 u8 serv_name[64]; /* Server host name */
643 u8 boot_file[128]; /* Name of boot file */
644 u8 exten[312]; /* DHCP options / BOOTP vendor extensions */
645};
646
647/* packet ops */
648#define BOOTP_REQUEST 1
649#define BOOTP_REPLY 2
650
651/* DHCP message types */
652#define DHCPDISCOVER 1
653#define DHCPOFFER 2
654#define DHCPREQUEST 3
655#define DHCPDECLINE 4
656#define DHCPACK 5
657#define DHCPNAK 6
658#define DHCPRELEASE 7
659#define DHCPINFORM 8
660
661static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
662
663static struct packet_type bootp_packet_type __initdata = {
664 .type = cpu_to_be16(ETH_P_IP),
665 .func = ic_bootp_recv,
666};
667
668/* DHCPACK can overwrite DNS if fallback was set upon first BOOTP reply */
669static int ic_nameservers_fallback __initdata;
670
671/*
672 * Initialize DHCP/BOOTP extension fields in the request.
673 */
674
675static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
676
677#ifdef IPCONFIG_DHCP
678
679static void __init
680ic_dhcp_init_options(u8 *options, struct ic_device *d)
681{
682 u8 mt = ((ic_servaddr == NONE)
683 ? DHCPDISCOVER : DHCPREQUEST);
684 u8 *e = options;
685 int len;
686
687 pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
688
689 memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */
690 e += 4;
691
692 *e++ = 53; /* DHCP message type */
693 *e++ = 1;
694 *e++ = mt;
695
696 if (mt == DHCPREQUEST) {
697 *e++ = 54; /* Server ID (IP address) */
698 *e++ = 4;
699 memcpy(e, &ic_servaddr, 4);
700 e += 4;
701
702 *e++ = 50; /* Requested IP address */
703 *e++ = 4;
704 memcpy(e, &ic_myaddr, 4);
705 e += 4;
706 }
707
708 /* always? */
709 {
710 static const u8 ic_req_params[] = {
711 1, /* Subnet mask */
712 3, /* Default gateway */
713 6, /* DNS server */
714 12, /* Host name */
715 15, /* Domain name */
716 17, /* Boot path */
717 26, /* MTU */
718 40, /* NIS domain name */
719 42, /* NTP servers */
720 };
721
722 *e++ = 55; /* Parameter request list */
723 *e++ = sizeof(ic_req_params);
724 memcpy(e, ic_req_params, sizeof(ic_req_params));
725 e += sizeof(ic_req_params);
726
727 if (ic_host_name_set) {
728 *e++ = 12; /* host-name */
729 len = strlen(utsname()->nodename);
730 *e++ = len;
731 memcpy(e, utsname()->nodename, len);
732 e += len;
733 }
734 if (*vendor_class_identifier) {
735 pr_info("DHCP: sending class identifier \"%s\"\n",
736 vendor_class_identifier);
737 *e++ = 60; /* Class-identifier */
738 len = strlen(vendor_class_identifier);
739 *e++ = len;
740 memcpy(e, vendor_class_identifier, len);
741 e += len;
742 }
743 len = strlen(dhcp_client_identifier + 1);
744 /* the minimum length of identifier is 2, include 1 byte type,
745 * and can not be larger than the length of options
746 */
747 if (len >= 1 && len < 312 - (e - options) - 1) {
748 *e++ = 61;
749 *e++ = len + 1;
750 memcpy(e, dhcp_client_identifier, len + 1);
751 e += len + 1;
752 }
753 }
754
755 *e++ = 255; /* End of the list */
756}
757
758#endif /* IPCONFIG_DHCP */
759
760static void __init ic_bootp_init_ext(u8 *e)
761{
762 memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */
763 e += 4;
764 *e++ = 1; /* Subnet mask request */
765 *e++ = 4;
766 e += 4;
767 *e++ = 3; /* Default gateway request */
768 *e++ = 4;
769 e += 4;
770#if CONF_NAMESERVERS_MAX > 0
771 *e++ = 6; /* (DNS) name server request */
772 *e++ = 4 * CONF_NAMESERVERS_MAX;
773 e += 4 * CONF_NAMESERVERS_MAX;
774#endif
775 *e++ = 12; /* Host name request */
776 *e++ = 32;
777 e += 32;
778 *e++ = 40; /* NIS Domain name request */
779 *e++ = 32;
780 e += 32;
781 *e++ = 17; /* Boot path */
782 *e++ = 40;
783 e += 40;
784
785 *e++ = 57; /* set extension buffer size for reply */
786 *e++ = 2;
787 *e++ = 1; /* 128+236+8+20+14, see dhcpd sources */
788 *e++ = 150;
789
790 *e++ = 255; /* End of the list */
791}
792
793
794/*
795 * Initialize the DHCP/BOOTP mechanism.
796 */
797static inline void __init ic_bootp_init(void)
798{
799 /* Re-initialise all name servers and NTP servers to NONE, in case any
800 * were set via the "ip=" or "nfsaddrs=" kernel command line parameters:
801 * any IP addresses specified there will already have been decoded but
802 * are no longer needed
803 */
804 ic_nameservers_predef();
805 ic_ntp_servers_predef();
806
807 dev_add_pack(pt: &bootp_packet_type);
808}
809
810
811/*
812 * DHCP/BOOTP cleanup.
813 */
814static inline void __init ic_bootp_cleanup(void)
815{
816 dev_remove_pack(pt: &bootp_packet_type);
817}
818
819
820/*
821 * Send DHCP/BOOTP request to single interface.
822 */
823static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
824{
825 struct net_device *dev = d->dev;
826 struct sk_buff *skb;
827 struct bootp_pkt *b;
828 struct iphdr *h;
829 int hlen = LL_RESERVED_SPACE(dev);
830 int tlen = dev->needed_tailroom;
831
832 /* Allocate packet */
833 skb = alloc_skb(size: sizeof(struct bootp_pkt) + hlen + tlen + 15,
834 GFP_KERNEL);
835 if (!skb)
836 return;
837 skb_reserve(skb, len: hlen);
838 b = skb_put_zero(skb, len: sizeof(struct bootp_pkt));
839
840 /* Construct IP header */
841 skb_reset_network_header(skb);
842 h = ip_hdr(skb);
843 h->version = 4;
844 h->ihl = 5;
845 h->tot_len = htons(sizeof(struct bootp_pkt));
846 h->frag_off = htons(IP_DF);
847 h->ttl = 64;
848 h->protocol = IPPROTO_UDP;
849 h->daddr = htonl(INADDR_BROADCAST);
850 h->check = ip_fast_csum(iph: (unsigned char *) h, ihl: h->ihl);
851
852 /* Construct UDP header */
853 b->udph.source = htons(68);
854 b->udph.dest = htons(67);
855 b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
856 /* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
857
858 /* Construct DHCP/BOOTP header */
859 b->op = BOOTP_REQUEST;
860 if (dev->type < 256) /* check for false types */
861 b->htype = dev->type;
862 else if (dev->type == ARPHRD_FDDI)
863 b->htype = ARPHRD_ETHER;
864 else {
865 pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
866 dev->name);
867 b->htype = dev->type; /* can cause undefined behavior */
868 }
869
870 /* server_ip and your_ip address are both already zero per RFC2131 */
871 b->hlen = dev->addr_len;
872 memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
873 b->secs = htons(jiffies_diff / HZ);
874 b->xid = d->xid;
875
876 /* add DHCP options or BOOTP extensions */
877#ifdef IPCONFIG_DHCP
878 if (ic_proto_enabled & IC_USE_DHCP)
879 ic_dhcp_init_options(options: b->exten, d);
880 else
881#endif
882 ic_bootp_init_ext(e: b->exten);
883
884 /* Chain packet down the line... */
885 skb->dev = dev;
886 skb->protocol = htons(ETH_P_IP);
887 if (dev_hard_header(skb, dev, ntohs(skb->protocol),
888 daddr: dev->broadcast, saddr: dev->dev_addr, len: skb->len) < 0) {
889 kfree_skb(skb);
890 printk("E");
891 return;
892 }
893
894 if (dev_queue_xmit(skb) < 0)
895 printk("E");
896}
897
898
899/*
900 * Copy BOOTP-supplied string
901 */
902static int __init ic_bootp_string(char *dest, char *src, int len, int max)
903{
904 if (!len)
905 return 0;
906 if (len > max-1)
907 len = max-1;
908 memcpy(dest, src, len);
909 dest[len] = '\0';
910 return 1;
911}
912
913
914/*
915 * Process BOOTP extensions.
916 */
917static void __init ic_do_bootp_ext(u8 *ext)
918{
919 u8 servers;
920 int i;
921 __be16 mtu;
922
923 u8 *c;
924
925 pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
926 for (c=ext+2; c<ext+2+ext[1]; c++)
927 pr_debug(" %02x", *c);
928 pr_debug("\n");
929
930 switch (*ext++) {
931 case 1: /* Subnet mask */
932 if (ic_netmask == NONE)
933 memcpy(&ic_netmask, ext+1, 4);
934 break;
935 case 3: /* Default gateway */
936 if (ic_gateway == NONE)
937 memcpy(&ic_gateway, ext+1, 4);
938 break;
939 case 6: /* DNS server */
940 servers= *ext/4;
941 if (servers > CONF_NAMESERVERS_MAX)
942 servers = CONF_NAMESERVERS_MAX;
943 for (i = 0; i < servers; i++) {
944 if (ic_nameservers[i] == NONE ||
945 ic_nameservers_fallback)
946 memcpy(&ic_nameservers[i], ext+1+4*i, 4);
947 }
948 break;
949 case 12: /* Host name */
950 if (!ic_host_name_set) {
951 ic_bootp_string(dest: utsname()->nodename, src: ext+1, len: *ext,
952 __NEW_UTS_LEN);
953 ic_host_name_set = 1;
954 }
955 break;
956 case 15: /* Domain name (DNS) */
957 if (!ic_domain[0])
958 ic_bootp_string(dest: ic_domain, src: ext+1, len: *ext, max: sizeof(ic_domain));
959 break;
960 case 17: /* Root path */
961 if (!root_server_path[0])
962 ic_bootp_string(dest: root_server_path, src: ext+1, len: *ext,
963 max: sizeof(root_server_path));
964 break;
965 case 26: /* Interface MTU */
966 memcpy(&mtu, ext+1, sizeof(mtu));
967 ic_dev_mtu = ntohs(mtu);
968 break;
969 case 40: /* NIS Domain name (_not_ DNS) */
970 ic_bootp_string(dest: utsname()->domainname, src: ext+1, len: *ext,
971 __NEW_UTS_LEN);
972 break;
973 case 42: /* NTP servers */
974 servers = *ext / 4;
975 if (servers > CONF_NTP_SERVERS_MAX)
976 servers = CONF_NTP_SERVERS_MAX;
977 for (i = 0; i < servers; i++) {
978 if (ic_ntp_servers[i] == NONE)
979 memcpy(&ic_ntp_servers[i], ext+1+4*i, 4);
980 }
981 break;
982 }
983}
984
985
986/*
987 * Receive BOOTP reply.
988 */
989static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
990{
991 struct bootp_pkt *b;
992 struct iphdr *h;
993 struct ic_device *d;
994 int len, ext_len;
995
996 if (!net_eq(net1: dev_net(dev), net2: &init_net))
997 goto drop;
998
999 /* Perform verifications before taking the lock. */
1000 if (skb->pkt_type == PACKET_OTHERHOST)
1001 goto drop;
1002
1003 skb = skb_share_check(skb, GFP_ATOMIC);
1004 if (!skb)
1005 return NET_RX_DROP;
1006
1007 if (!pskb_may_pull(skb,
1008 len: sizeof(struct iphdr) +
1009 sizeof(struct udphdr)))
1010 goto drop;
1011
1012 b = (struct bootp_pkt *)skb_network_header(skb);
1013 h = &b->iph;
1014
1015 if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
1016 goto drop;
1017
1018 /* Fragments are not supported */
1019 if (ip_is_fragment(iph: h)) {
1020 net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
1021 goto drop;
1022 }
1023
1024 if (skb->len < ntohs(h->tot_len))
1025 goto drop;
1026
1027 if (ip_fast_csum(iph: (char *) h, ihl: h->ihl))
1028 goto drop;
1029
1030 if (b->udph.source != htons(67) || b->udph.dest != htons(68))
1031 goto drop;
1032
1033 if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
1034 goto drop;
1035
1036 len = ntohs(b->udph.len) - sizeof(struct udphdr);
1037 ext_len = len - (sizeof(*b) -
1038 sizeof(struct iphdr) -
1039 sizeof(struct udphdr) -
1040 sizeof(b->exten));
1041 if (ext_len < 0)
1042 goto drop;
1043
1044 /* Ok the front looks good, make sure we can get at the rest. */
1045 if (!pskb_may_pull(skb, len: skb->len))
1046 goto drop;
1047
1048 b = (struct bootp_pkt *)skb_network_header(skb);
1049 h = &b->iph;
1050
1051 /* One reply at a time, please. */
1052 spin_lock(lock: &ic_recv_lock);
1053
1054 /* If we already have a reply, just drop the packet */
1055 if (ic_got_reply)
1056 goto drop_unlock;
1057
1058 /* Find the ic_device that the packet arrived on */
1059 d = ic_first_dev;
1060 while (d && d->dev != dev)
1061 d = d->next;
1062 if (!d)
1063 goto drop_unlock; /* should never happen */
1064
1065 /* Is it a reply to our BOOTP request? */
1066 if (b->op != BOOTP_REPLY ||
1067 b->xid != d->xid) {
1068 net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1069 d->dev->name, b->op, b->xid);
1070 goto drop_unlock;
1071 }
1072
1073 /* Parse extensions */
1074 if (ext_len >= 4 &&
1075 !memcmp(p: b->exten, q: ic_bootp_cookie, size: 4)) { /* Check magic cookie */
1076 u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1077 u8 *ext;
1078
1079#ifdef IPCONFIG_DHCP
1080 if (ic_proto_enabled & IC_USE_DHCP) {
1081 __be32 server_id = NONE;
1082 int mt = 0;
1083
1084 ext = &b->exten[4];
1085 while (ext < end && *ext != 0xff) {
1086 u8 *opt = ext++;
1087 if (*opt == 0) /* Padding */
1088 continue;
1089 ext += *ext + 1;
1090 if (ext >= end)
1091 break;
1092 switch (*opt) {
1093 case 53: /* Message type */
1094 if (opt[1])
1095 mt = opt[2];
1096 break;
1097 case 54: /* Server ID (IP address) */
1098 if (opt[1] >= 4)
1099 memcpy(&server_id, opt + 2, 4);
1100 break;
1101 }
1102 }
1103
1104 pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1105
1106 switch (mt) {
1107 case DHCPOFFER:
1108 /* While in the process of accepting one offer,
1109 * ignore all others.
1110 */
1111 if (ic_myaddr != NONE)
1112 goto drop_unlock;
1113
1114 /* Let's accept that offer. */
1115 ic_myaddr = b->your_ip;
1116 ic_servaddr = server_id;
1117 pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1118 &ic_myaddr, &b->iph.saddr);
1119 /* The DHCP indicated server address takes
1120 * precedence over the bootp header one if
1121 * they are different.
1122 */
1123 if ((server_id != NONE) &&
1124 (b->server_ip != server_id))
1125 b->server_ip = ic_servaddr;
1126 break;
1127
1128 case DHCPACK:
1129 if (memcmp(p: dev->dev_addr, q: b->hw_addr, size: dev->addr_len) != 0)
1130 goto drop_unlock;
1131
1132 /* Yeah! */
1133 break;
1134
1135 default:
1136 /* Urque. Forget it*/
1137 ic_myaddr = NONE;
1138 ic_servaddr = NONE;
1139 goto drop_unlock;
1140 }
1141
1142 ic_dhcp_msgtype = mt;
1143
1144 }
1145#endif /* IPCONFIG_DHCP */
1146
1147 ext = &b->exten[4];
1148 while (ext < end && *ext != 0xff) {
1149 u8 *opt = ext++;
1150 if (*opt == 0) /* Padding */
1151 continue;
1152 ext += *ext + 1;
1153 if (ext < end)
1154 ic_do_bootp_ext(ext: opt);
1155 }
1156 }
1157
1158 /* We have a winner! */
1159 ic_dev = d;
1160 ic_myaddr = b->your_ip;
1161 ic_servaddr = b->server_ip;
1162 ic_addrservaddr = b->iph.saddr;
1163 if (ic_gateway == NONE && b->relay_ip)
1164 ic_gateway = b->relay_ip;
1165 if (ic_nameservers[0] == NONE) {
1166 ic_nameservers[0] = ic_servaddr;
1167 ic_nameservers_fallback = 1;
1168 }
1169 ic_got_reply = IC_BOOTP;
1170
1171drop_unlock:
1172 /* Show's over. Nothing to see here. */
1173 spin_unlock(lock: &ic_recv_lock);
1174
1175drop:
1176 /* Throw the packet out. */
1177 kfree_skb(skb);
1178
1179 return 0;
1180}
1181
1182
1183#endif
1184
1185
1186/*
1187 * Dynamic IP configuration -- DHCP, BOOTP, RARP.
1188 */
1189
1190#ifdef IPCONFIG_DYNAMIC
1191
1192static int __init ic_dynamic(void)
1193{
1194 int retries;
1195 struct ic_device *d;
1196 unsigned long start_jiffies, timeout, jiff;
1197 int do_bootp = ic_proto_have_if & IC_BOOTP;
1198 int do_rarp = ic_proto_have_if & IC_RARP;
1199
1200 /*
1201 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1202 * This routine gets only called when some pieces of information
1203 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1204 */
1205 if (!ic_proto_enabled) {
1206 pr_err("IP-Config: Incomplete network configuration information\n");
1207 return -1;
1208 }
1209
1210#ifdef IPCONFIG_BOOTP
1211 if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1212 pr_err("DHCP/BOOTP: No suitable device found\n");
1213#endif
1214#ifdef IPCONFIG_RARP
1215 if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1216 pr_err("RARP: No suitable device found\n");
1217#endif
1218
1219 if (!ic_proto_have_if)
1220 /* Error message already printed */
1221 return -1;
1222
1223 /*
1224 * Setup protocols
1225 */
1226#ifdef IPCONFIG_BOOTP
1227 if (do_bootp)
1228 ic_bootp_init();
1229#endif
1230#ifdef IPCONFIG_RARP
1231 if (do_rarp)
1232 ic_rarp_init();
1233#endif
1234
1235 /*
1236 * Send requests and wait, until we get an answer. This loop
1237 * seems to be a terrible waste of CPU time, but actually there is
1238 * only one process running at all, so we don't need to use any
1239 * scheduler functions.
1240 * [Actually we could now, but the nothing else running note still
1241 * applies.. - AC]
1242 */
1243 pr_notice("Sending %s%s%s requests .",
1244 do_bootp
1245 ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1246 (do_bootp && do_rarp) ? " and " : "",
1247 do_rarp ? "RARP" : "");
1248
1249 start_jiffies = jiffies;
1250 d = ic_first_dev;
1251 retries = CONF_SEND_RETRIES;
1252 get_random_bytes(buf: &timeout, len: sizeof(timeout));
1253 timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1254 for (;;) {
1255#ifdef IPCONFIG_BOOTP
1256 if (do_bootp && (d->able & IC_BOOTP))
1257 ic_bootp_send_if(d, jiffies_diff: jiffies - start_jiffies);
1258#endif
1259#ifdef IPCONFIG_RARP
1260 if (do_rarp && (d->able & IC_RARP))
1261 ic_rarp_send_if(d);
1262#endif
1263
1264 if (!d->next) {
1265 jiff = jiffies + timeout;
1266 while (time_before(jiffies, jiff) && !ic_got_reply)
1267 schedule_timeout_uninterruptible(timeout: 1);
1268 }
1269#ifdef IPCONFIG_DHCP
1270 /* DHCP isn't done until we get a DHCPACK. */
1271 if ((ic_got_reply & IC_BOOTP) &&
1272 (ic_proto_enabled & IC_USE_DHCP) &&
1273 ic_dhcp_msgtype != DHCPACK) {
1274 ic_got_reply = 0;
1275 /* continue on device that got the reply */
1276 d = ic_dev;
1277 pr_cont(",");
1278 continue;
1279 }
1280#endif /* IPCONFIG_DHCP */
1281
1282 if (ic_got_reply) {
1283 pr_cont(" OK\n");
1284 break;
1285 }
1286
1287 if ((d = d->next))
1288 continue;
1289
1290 if (! --retries) {
1291 pr_cont(" timed out!\n");
1292 break;
1293 }
1294
1295 d = ic_first_dev;
1296
1297 timeout = timeout CONF_TIMEOUT_MULT;
1298 if (timeout > CONF_TIMEOUT_MAX)
1299 timeout = CONF_TIMEOUT_MAX;
1300
1301 pr_cont(".");
1302 }
1303
1304#ifdef IPCONFIG_BOOTP
1305 if (do_bootp)
1306 ic_bootp_cleanup();
1307#endif
1308#ifdef IPCONFIG_RARP
1309 if (do_rarp)
1310 ic_rarp_cleanup();
1311#endif
1312
1313 if (!ic_got_reply) {
1314 ic_myaddr = NONE;
1315 return -1;
1316 }
1317
1318 pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1319 ((ic_got_reply & IC_RARP) ? "RARP"
1320 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1321 &ic_addrservaddr, &ic_myaddr);
1322
1323 return 0;
1324}
1325
1326#endif /* IPCONFIG_DYNAMIC */
1327
1328#ifdef CONFIG_PROC_FS
1329/* proc_dir_entry for /proc/net/ipconfig */
1330static struct proc_dir_entry *ipconfig_dir;
1331
1332/* Name servers: */
1333static int pnp_seq_show(struct seq_file *seq, void *v)
1334{
1335 int i;
1336
1337 if (ic_proto_used & IC_PROTO)
1338 seq_printf(m: seq, fmt: "#PROTO: %s\n",
1339 (ic_proto_used & IC_RARP) ? "RARP"
1340 : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1341 else
1342 seq_puts(m: seq, s: "#MANUAL\n");
1343
1344 if (ic_domain[0])
1345 seq_printf(m: seq,
1346 fmt: "domain %s\n", ic_domain);
1347 for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1348 if (ic_nameservers[i] != NONE)
1349 seq_printf(m: seq, fmt: "nameserver %pI4\n",
1350 &ic_nameservers[i]);
1351 }
1352 if (ic_servaddr != NONE)
1353 seq_printf(m: seq, fmt: "bootserver %pI4\n",
1354 &ic_servaddr);
1355 return 0;
1356}
1357
1358/* Create the /proc/net/ipconfig directory */
1359static int __init ipconfig_proc_net_init(void)
1360{
1361 ipconfig_dir = proc_net_mkdir(net: &init_net, name: "ipconfig", parent: init_net.proc_net);
1362 if (!ipconfig_dir)
1363 return -ENOMEM;
1364
1365 return 0;
1366}
1367
1368/* Create a new file under /proc/net/ipconfig */
1369static int ipconfig_proc_net_create(const char *name,
1370 const struct proc_ops *proc_ops)
1371{
1372 char *pname;
1373 struct proc_dir_entry *p;
1374
1375 if (!ipconfig_dir)
1376 return -ENOMEM;
1377
1378 pname = kasprintf(GFP_KERNEL, fmt: "%s%s", "ipconfig/", name);
1379 if (!pname)
1380 return -ENOMEM;
1381
1382 p = proc_create(name: pname, mode: 0444, parent: init_net.proc_net, proc_ops);
1383 kfree(objp: pname);
1384 if (!p)
1385 return -ENOMEM;
1386
1387 return 0;
1388}
1389
1390/* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */
1391static int ntp_servers_show(struct seq_file *seq, void *v)
1392{
1393 int i;
1394
1395 for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1396 if (ic_ntp_servers[i] != NONE)
1397 seq_printf(m: seq, fmt: "%pI4\n", &ic_ntp_servers[i]);
1398 }
1399 return 0;
1400}
1401DEFINE_PROC_SHOW_ATTRIBUTE(ntp_servers);
1402#endif /* CONFIG_PROC_FS */
1403
1404/*
1405 * Extract IP address from the parameter string if needed. Note that we
1406 * need to have root_server_addr set _before_ IPConfig gets called as it
1407 * can override it.
1408 */
1409__be32 __init root_nfs_parse_addr(char *name)
1410{
1411 __be32 addr;
1412 int octets = 0;
1413 char *cp, *cq;
1414
1415 cp = cq = name;
1416 while (octets < 4) {
1417 while (*cp >= '0' && *cp <= '9')
1418 cp++;
1419 if (cp == cq || cp - cq > 3)
1420 break;
1421 if (*cp == '.' || octets == 3)
1422 octets++;
1423 if (octets < 4)
1424 cp++;
1425 cq = cp;
1426 }
1427 if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1428 if (*cp == ':')
1429 *cp++ = '\0';
1430 addr = in_aton(str: name);
1431 memmove(name, cp, strlen(cp) + 1);
1432 } else
1433 addr = NONE;
1434
1435 return addr;
1436}
1437
1438#define DEVICE_WAIT_MAX 12 /* 12 seconds */
1439
1440static int __init wait_for_devices(void)
1441{
1442 int i;
1443 bool try_init_devs = true;
1444
1445 for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1446 struct net_device *dev;
1447 int found = 0;
1448
1449 /* make sure deferred device probes are finished */
1450 wait_for_device_probe();
1451
1452 rtnl_lock();
1453 for_each_netdev(&init_net, dev) {
1454 if (ic_is_init_dev(dev)) {
1455 found = 1;
1456 break;
1457 }
1458 }
1459 rtnl_unlock();
1460 if (found)
1461 return 0;
1462 if (try_init_devs &&
1463 (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) {
1464 try_init_devs = false;
1465 wait_for_init_devices_probe();
1466 }
1467 ssleep(seconds: 1);
1468 }
1469 return -ENODEV;
1470}
1471
1472/*
1473 * IP Autoconfig dispatcher.
1474 */
1475
1476static int __init ip_auto_config(void)
1477{
1478 __be32 addr;
1479#ifdef IPCONFIG_DYNAMIC
1480 int retries = CONF_OPEN_RETRIES;
1481#endif
1482 int err;
1483 unsigned int i, count;
1484
1485 /* Initialise all name servers and NTP servers to NONE (but only if the
1486 * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded,
1487 * otherwise we'll overwrite the IP addresses specified there)
1488 */
1489 if (ic_set_manually == 0) {
1490 ic_nameservers_predef();
1491 ic_ntp_servers_predef();
1492 }
1493
1494#ifdef CONFIG_PROC_FS
1495 proc_create_single("pnp", 0444, init_net.proc_net, pnp_seq_show);
1496
1497 if (ipconfig_proc_net_init() == 0)
1498 ipconfig_proc_net_create(name: "ntp_servers", proc_ops: &ntp_servers_proc_ops);
1499#endif /* CONFIG_PROC_FS */
1500
1501 if (!ic_enable)
1502 return 0;
1503
1504 pr_debug("IP-Config: Entered.\n");
1505#ifdef IPCONFIG_DYNAMIC
1506 try_try_again:
1507#endif
1508 /* Wait for devices to appear */
1509 err = wait_for_devices();
1510 if (err)
1511 return err;
1512
1513 /* Setup all network devices */
1514 err = ic_open_devs();
1515 if (err)
1516 return err;
1517
1518 /* Give drivers a chance to settle */
1519 msleep(CONF_POST_OPEN);
1520
1521 /*
1522 * If the config information is insufficient (e.g., our IP address or
1523 * IP address of the boot server is missing or we have multiple network
1524 * interfaces and no default was set), use BOOTP or RARP to get the
1525 * missing values.
1526 */
1527 if (ic_myaddr == NONE ||
1528#if defined(CONFIG_ROOT_NFS) || defined(CONFIG_CIFS_ROOT)
1529 (root_server_addr == NONE &&
1530 ic_servaddr == NONE &&
1531 (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) ||
1532#endif
1533 ic_first_dev->next) {
1534#ifdef IPCONFIG_DYNAMIC
1535 if (ic_dynamic() < 0) {
1536 ic_close_devs();
1537
1538 /*
1539 * I don't know why, but sometimes the
1540 * eepro100 driver (at least) gets upset and
1541 * doesn't work the first time it's opened.
1542 * But then if you close it and reopen it, it
1543 * works just fine. So we need to try that at
1544 * least once before giving up.
1545 *
1546 * Also, if the root will be NFS-mounted, we
1547 * have nowhere to go if DHCP fails. So we
1548 * just have to keep trying forever.
1549 *
1550 * -- Chip
1551 */
1552#ifdef CONFIG_ROOT_NFS
1553 if (ROOT_DEV == Root_NFS) {
1554 pr_err("IP-Config: Retrying forever (NFS root)...\n");
1555 goto try_try_again;
1556 }
1557#endif
1558#ifdef CONFIG_CIFS_ROOT
1559 if (ROOT_DEV == Root_CIFS) {
1560 pr_err("IP-Config: Retrying forever (CIFS root)...\n");
1561 goto try_try_again;
1562 }
1563#endif
1564
1565 if (--retries) {
1566 pr_err("IP-Config: Reopening network devices...\n");
1567 goto try_try_again;
1568 }
1569
1570 /* Oh, well. At least we tried. */
1571 pr_err("IP-Config: Auto-configuration of network failed\n");
1572 return -1;
1573 }
1574#else /* !DYNAMIC */
1575 pr_err("IP-Config: Incomplete network configuration information\n");
1576 ic_close_devs();
1577 return -1;
1578#endif /* IPCONFIG_DYNAMIC */
1579 } else {
1580 /* Device selected manually or only one device -> use it */
1581 ic_dev = ic_first_dev;
1582 }
1583
1584 addr = root_nfs_parse_addr(name: root_server_path);
1585 if (root_server_addr == NONE)
1586 root_server_addr = addr;
1587
1588 /*
1589 * Use defaults wherever applicable.
1590 */
1591 if (ic_defaults() < 0)
1592 return -1;
1593
1594 /*
1595 * Record which protocol was actually used.
1596 */
1597#ifdef IPCONFIG_DYNAMIC
1598 ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1599#endif
1600
1601#ifndef IPCONFIG_SILENT
1602 /*
1603 * Clue in the operator.
1604 */
1605 pr_info("IP-Config: Complete:\n");
1606
1607 pr_info(" device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1608 ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1609 &ic_myaddr, &ic_netmask, &ic_gateway);
1610 pr_info(" host=%s, domain=%s, nis-domain=%s\n",
1611 utsname()->nodename, ic_domain, utsname()->domainname);
1612 pr_info(" bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1613 &ic_servaddr, &root_server_addr, root_server_path);
1614 if (ic_dev_mtu)
1615 pr_cont(", mtu=%d", ic_dev_mtu);
1616 /* Name servers (if any): */
1617 for (i = 0, count = 0; i < CONF_NAMESERVERS_MAX; i++) {
1618 if (ic_nameservers[i] != NONE) {
1619 if (i == 0)
1620 pr_info(" nameserver%u=%pI4",
1621 i, &ic_nameservers[i]);
1622 else
1623 pr_cont(", nameserver%u=%pI4",
1624 i, &ic_nameservers[i]);
1625
1626 count++;
1627 }
1628 if ((i + 1 == CONF_NAMESERVERS_MAX) && count > 0)
1629 pr_cont("\n");
1630 }
1631 /* NTP servers (if any): */
1632 for (i = 0, count = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1633 if (ic_ntp_servers[i] != NONE) {
1634 if (i == 0)
1635 pr_info(" ntpserver%u=%pI4",
1636 i, &ic_ntp_servers[i]);
1637 else
1638 pr_cont(", ntpserver%u=%pI4",
1639 i, &ic_ntp_servers[i]);
1640
1641 count++;
1642 }
1643 if ((i + 1 == CONF_NTP_SERVERS_MAX) && count > 0)
1644 pr_cont("\n");
1645 }
1646#endif /* !SILENT */
1647
1648 /*
1649 * Close all network devices except the device we've
1650 * autoconfigured and set up routes.
1651 */
1652 if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1653 err = -1;
1654 else
1655 err = 0;
1656
1657 ic_close_devs();
1658
1659 return err;
1660}
1661
1662late_initcall(ip_auto_config);
1663
1664
1665/*
1666 * Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1667 * command line parameter. See Documentation/admin-guide/nfs/nfsroot.rst.
1668 */
1669static int __init ic_proto_name(char *name)
1670{
1671 if (!strcmp(name, "on") || !strcmp(name, "any")) {
1672 return 1;
1673 }
1674 if (!strcmp(name, "off") || !strcmp(name, "none")) {
1675 return 0;
1676 }
1677#ifdef CONFIG_IP_PNP_DHCP
1678 else if (!strncmp(name, "dhcp", 4)) {
1679 char *client_id;
1680
1681 ic_proto_enabled &= ~IC_RARP;
1682 client_id = strstr(name, "dhcp,");
1683 if (client_id) {
1684 char *v;
1685
1686 client_id = client_id + 5;
1687 v = strchr(client_id, ',');
1688 if (!v)
1689 return 1;
1690 *v = 0;
1691 if (kstrtou8(s: client_id, base: 0, res: dhcp_client_identifier))
1692 pr_debug("DHCP: Invalid client identifier type\n");
1693 strncpy(p: dhcp_client_identifier + 1, q: v + 1, size: 251);
1694 *v = ',';
1695 }
1696 return 1;
1697 }
1698#endif
1699#ifdef CONFIG_IP_PNP_BOOTP
1700 else if (!strcmp(name, "bootp")) {
1701 ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1702 return 1;
1703 }
1704#endif
1705#ifdef CONFIG_IP_PNP_RARP
1706 else if (!strcmp(name, "rarp")) {
1707 ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1708 return 1;
1709 }
1710#endif
1711#ifdef IPCONFIG_DYNAMIC
1712 else if (!strcmp(name, "both")) {
1713 ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1714 return 1;
1715 }
1716#endif
1717 return 0;
1718}
1719
1720static int __init ip_auto_config_setup(char *addrs)
1721{
1722 char *cp, *ip, *dp;
1723 int num = 0;
1724
1725 ic_set_manually = 1;
1726 ic_enable = 1;
1727
1728 /*
1729 * If any dhcp, bootp etc options are set, leave autoconfig on
1730 * and skip the below static IP processing.
1731 */
1732 if (ic_proto_name(name: addrs))
1733 return 1;
1734
1735 /* If no static IP is given, turn off autoconfig and bail. */
1736 if (*addrs == 0 ||
1737 strcmp(addrs, "off") == 0 ||
1738 strcmp(addrs, "none") == 0) {
1739 ic_enable = 0;
1740 return 1;
1741 }
1742
1743 /* Initialise all name servers and NTP servers to NONE */
1744 ic_nameservers_predef();
1745 ic_ntp_servers_predef();
1746
1747 /* Parse string for static IP assignment. */
1748 ip = addrs;
1749 while (ip && *ip) {
1750 if ((cp = strchr(ip, ':')))
1751 *cp++ = '\0';
1752 if (strlen(ip) > 0) {
1753 pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1754 switch (num) {
1755 case 0:
1756 if ((ic_myaddr = in_aton(str: ip)) == ANY)
1757 ic_myaddr = NONE;
1758 break;
1759 case 1:
1760 if ((ic_servaddr = in_aton(str: ip)) == ANY)
1761 ic_servaddr = NONE;
1762 break;
1763 case 2:
1764 if ((ic_gateway = in_aton(str: ip)) == ANY)
1765 ic_gateway = NONE;
1766 break;
1767 case 3:
1768 if ((ic_netmask = in_aton(str: ip)) == ANY)
1769 ic_netmask = NONE;
1770 break;
1771 case 4:
1772 if ((dp = strchr(ip, '.'))) {
1773 *dp++ = '\0';
1774 strscpy(utsname()->domainname, dp,
1775 sizeof(utsname()->domainname));
1776 }
1777 strscpy(utsname()->nodename, ip,
1778 sizeof(utsname()->nodename));
1779 ic_host_name_set = 1;
1780 break;
1781 case 5:
1782 strscpy(user_dev_name, ip, sizeof(user_dev_name));
1783 break;
1784 case 6:
1785 if (ic_proto_name(name: ip) == 0 &&
1786 ic_myaddr == NONE) {
1787 ic_enable = 0;
1788 }
1789 break;
1790 case 7:
1791 if (CONF_NAMESERVERS_MAX >= 1) {
1792 ic_nameservers[0] = in_aton(str: ip);
1793 if (ic_nameservers[0] == ANY)
1794 ic_nameservers[0] = NONE;
1795 }
1796 break;
1797 case 8:
1798 if (CONF_NAMESERVERS_MAX >= 2) {
1799 ic_nameservers[1] = in_aton(str: ip);
1800 if (ic_nameservers[1] == ANY)
1801 ic_nameservers[1] = NONE;
1802 }
1803 break;
1804 case 9:
1805 if (CONF_NTP_SERVERS_MAX >= 1) {
1806 ic_ntp_servers[0] = in_aton(str: ip);
1807 if (ic_ntp_servers[0] == ANY)
1808 ic_ntp_servers[0] = NONE;
1809 }
1810 break;
1811 }
1812 }
1813 ip = cp;
1814 num++;
1815 }
1816
1817 return 1;
1818}
1819__setup("ip=", ip_auto_config_setup);
1820
1821static int __init nfsaddrs_config_setup(char *addrs)
1822{
1823 return ip_auto_config_setup(addrs);
1824}
1825__setup("nfsaddrs=", nfsaddrs_config_setup);
1826
1827static int __init vendor_class_identifier_setup(char *addrs)
1828{
1829 if (strscpy(vendor_class_identifier, addrs,
1830 sizeof(vendor_class_identifier))
1831 >= sizeof(vendor_class_identifier))
1832 pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1833 vendor_class_identifier);
1834 return 1;
1835}
1836__setup("dhcpclass=", vendor_class_identifier_setup);
1837
1838static int __init set_carrier_timeout(char *str)
1839{
1840 ssize_t ret;
1841
1842 if (!str)
1843 return 0;
1844
1845 ret = kstrtouint(s: str, base: 0, res: &carrier_timeout);
1846 if (ret)
1847 return 0;
1848
1849 return 1;
1850}
1851__setup("carrier_timeout=", set_carrier_timeout);
1852

source code of linux/net/ipv4/ipconfig.c