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
ic_is_init_dev(struct net_device * dev)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
ic_open_devs(void)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_obj(struct ic_device))) {
248 rtnl_unlock();
249 return -ENOMEM;
250 }
251 d->dev = dev;
252 *last = d;
253 last = &d->next;
254 d->flags = oflags;
255 d->able = able;
256 if (able & IC_BOOTP)
257 get_random_bytes(&d->xid, sizeof(__be32));
258 else
259 d->xid = 0;
260 ic_proto_have_if |= able;
261 pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n",
262 dev->name, able, d->xid);
263 }
264 }
265 /* Devices with a complex topology like SFP ethernet interfaces needs
266 * the rtnl_lock at init. The carrier wait-loop must therefore run
267 * without holding it.
268 */
269 rtnl_unlock();
270
271 /* no point in waiting if we could not bring up at least one device */
272 if (!ic_first_dev)
273 goto have_carrier;
274
275 /* wait for a carrier on at least one device */
276 start = jiffies;
277 next_msg = start + secs_to_jiffies(20);
278 while (time_before(jiffies, start +
279 secs_to_jiffies(carrier_timeout))) {
280 int wait, elapsed;
281
282 rtnl_lock();
283 for_each_netdev(&init_net, dev)
284 if (ic_is_init_dev(dev) && netif_carrier_ok(dev)) {
285 rtnl_unlock();
286 goto have_carrier;
287 }
288 rtnl_unlock();
289
290 msleep(1);
291
292 if (time_before(jiffies, next_msg))
293 continue;
294
295 elapsed = jiffies_to_msecs(jiffies - start);
296 wait = (carrier_timeout * 1000 - elapsed + 500) / 1000;
297 pr_info("Waiting up to %d more seconds for network.\n", wait);
298 next_msg = jiffies + secs_to_jiffies(20);
299 }
300 have_carrier:
301
302 *last = NULL;
303
304 if (!ic_first_dev) {
305 if (user_dev_name[0])
306 pr_err("IP-Config: Device `%s' not found\n",
307 user_dev_name);
308 else
309 pr_err("IP-Config: No network devices available\n");
310 return -ENODEV;
311 }
312 return 0;
313 }
314
315 /* Close all network interfaces except the one we've autoconfigured, and its
316 * lowers, in case it's a stacked virtual interface.
317 */
ic_close_devs(void)318 static void __init ic_close_devs(void)
319 {
320 struct net_device *selected_dev = ic_dev ? ic_dev->dev : NULL;
321 struct ic_device *d, *next;
322 struct net_device *dev;
323
324 rtnl_lock();
325 next = ic_first_dev;
326 while ((d = next)) {
327 bool bring_down = (d != ic_dev);
328 struct net_device *lower;
329 struct list_head *iter;
330
331 next = d->next;
332 dev = d->dev;
333
334 if (selected_dev) {
335 netdev_for_each_lower_dev(selected_dev, lower, iter) {
336 if (dev == lower) {
337 bring_down = false;
338 break;
339 }
340 }
341 }
342 if (bring_down) {
343 pr_debug("IP-Config: Downing %s\n", dev->name);
344 dev_change_flags(dev, d->flags, NULL);
345 }
346 kfree(d);
347 }
348 rtnl_unlock();
349 }
350
351 /*
352 * Interface to various network functions.
353 */
354
355 static inline void
set_sockaddr(struct sockaddr_in * sin,__be32 addr,__be16 port)356 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
357 {
358 sin->sin_family = AF_INET;
359 sin->sin_addr.s_addr = addr;
360 sin->sin_port = port;
361 }
362
363 /*
364 * Set up interface addresses and routes.
365 */
366
ic_setup_if(void)367 static int __init ic_setup_if(void)
368 {
369 struct ifreq ir;
370 struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
371 int err;
372
373 memset(&ir, 0, sizeof(ir));
374 strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name);
375 set_sockaddr(sin, ic_myaddr, 0);
376 if ((err = devinet_ioctl(&init_net, SIOCSIFADDR, &ir)) < 0) {
377 pr_err("IP-Config: Unable to set interface address (%d)\n",
378 err);
379 return -1;
380 }
381 set_sockaddr(sin, ic_netmask, 0);
382 if ((err = devinet_ioctl(&init_net, SIOCSIFNETMASK, &ir)) < 0) {
383 pr_err("IP-Config: Unable to set interface netmask (%d)\n",
384 err);
385 return -1;
386 }
387 set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
388 if ((err = devinet_ioctl(&init_net, SIOCSIFBRDADDR, &ir)) < 0) {
389 pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
390 err);
391 return -1;
392 }
393 /* Handle the case where we need non-standard MTU on the boot link (a network
394 * using jumbo frames, for instance). If we can't set the mtu, don't error
395 * out, we'll try to muddle along.
396 */
397 if (ic_dev_mtu != 0) {
398 rtnl_lock();
399 if ((err = dev_set_mtu(ic_dev->dev, ic_dev_mtu)) < 0)
400 pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
401 ic_dev_mtu, err);
402 rtnl_unlock();
403 }
404 return 0;
405 }
406
ic_setup_routes(void)407 static int __init ic_setup_routes(void)
408 {
409 /* No need to setup device routes, only the default route... */
410
411 if (ic_gateway != NONE) {
412 struct rtentry rm;
413 int err;
414
415 memset(&rm, 0, sizeof(rm));
416 if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
417 pr_err("IP-Config: Gateway not on directly connected network\n");
418 return -1;
419 }
420 set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
421 set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
422 set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
423 rm.rt_flags = RTF_UP | RTF_GATEWAY;
424 if ((err = ip_rt_ioctl(&init_net, SIOCADDRT, &rm)) < 0) {
425 pr_err("IP-Config: Cannot add default route (%d)\n",
426 err);
427 return -1;
428 }
429 }
430
431 return 0;
432 }
433
434 /*
435 * Fill in default values for all missing parameters.
436 */
437
ic_defaults(void)438 static int __init ic_defaults(void)
439 {
440 /*
441 * At this point we have no userspace running so need not
442 * claim locks on system_utsname
443 */
444
445 if (!ic_host_name_set)
446 sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
447
448 if (root_server_addr == NONE)
449 root_server_addr = ic_servaddr;
450
451 if (ic_netmask == NONE) {
452 if (IN_CLASSA(ntohl(ic_myaddr)))
453 ic_netmask = htonl(IN_CLASSA_NET);
454 else if (IN_CLASSB(ntohl(ic_myaddr)))
455 ic_netmask = htonl(IN_CLASSB_NET);
456 else if (IN_CLASSC(ntohl(ic_myaddr)))
457 ic_netmask = htonl(IN_CLASSC_NET);
458 else if (IN_CLASSE(ntohl(ic_myaddr)))
459 ic_netmask = htonl(IN_CLASSE_NET);
460 else {
461 pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
462 &ic_myaddr);
463 return -1;
464 }
465 pr_notice("IP-Config: Guessing netmask %pI4\n",
466 &ic_netmask);
467 }
468
469 return 0;
470 }
471
472 /*
473 * RARP support.
474 */
475
476 #ifdef IPCONFIG_RARP
477
478 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
479
480 static struct packet_type rarp_packet_type __initdata = {
481 .type = cpu_to_be16(ETH_P_RARP),
482 .func = ic_rarp_recv,
483 };
484
ic_rarp_init(void)485 static inline void __init ic_rarp_init(void)
486 {
487 dev_add_pack(&rarp_packet_type);
488 }
489
ic_rarp_cleanup(void)490 static inline void __init ic_rarp_cleanup(void)
491 {
492 dev_remove_pack(&rarp_packet_type);
493 }
494
495 /*
496 * Process received RARP packet.
497 */
498 static int __init
ic_rarp_recv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)499 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
500 {
501 struct arphdr *rarp;
502 unsigned char *rarp_ptr;
503 __be32 sip, tip;
504 unsigned char *tha; /* t for "target" */
505 struct ic_device *d;
506
507 if (!net_eq(dev_net(dev), &init_net))
508 goto drop;
509
510 skb = skb_share_check(skb, GFP_ATOMIC);
511 if (!skb)
512 return NET_RX_DROP;
513
514 if (!pskb_may_pull(skb, sizeof(struct arphdr)))
515 goto drop;
516
517 /* Basic sanity checks can be done without the lock. */
518 rarp = (struct arphdr *)skb_transport_header(skb);
519
520 /* If this test doesn't pass, it's not IP, or we should
521 * ignore it anyway.
522 */
523 if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
524 goto drop;
525
526 /* If it's not a RARP reply, delete it. */
527 if (rarp->ar_op != htons(ARPOP_RREPLY))
528 goto drop;
529
530 /* If it's not Ethernet, delete it. */
531 if (rarp->ar_pro != htons(ETH_P_IP))
532 goto drop;
533
534 if (!pskb_may_pull(skb, arp_hdr_len(dev)))
535 goto drop;
536
537 /* OK, it is all there and looks valid, process... */
538 rarp = (struct arphdr *)skb_transport_header(skb);
539 rarp_ptr = (unsigned char *) (rarp + 1);
540
541 /* One reply at a time, please. */
542 spin_lock(&ic_recv_lock);
543
544 /* If we already have a reply, just drop the packet */
545 if (ic_got_reply)
546 goto drop_unlock;
547
548 /* Find the ic_device that the packet arrived on */
549 d = ic_first_dev;
550 while (d && d->dev != dev)
551 d = d->next;
552 if (!d)
553 goto drop_unlock; /* should never happen */
554
555 /* Extract variable-width fields */
556 rarp_ptr += dev->addr_len;
557 memcpy(&sip, rarp_ptr, 4);
558 rarp_ptr += 4;
559 tha = rarp_ptr;
560 rarp_ptr += dev->addr_len;
561 memcpy(&tip, rarp_ptr, 4);
562
563 /* Discard packets which are not meant for us. */
564 if (memcmp(tha, dev->dev_addr, dev->addr_len))
565 goto drop_unlock;
566
567 /* Discard packets which are not from specified server. */
568 if (ic_servaddr != NONE && ic_servaddr != sip)
569 goto drop_unlock;
570
571 /* We have a winner! */
572 ic_dev = d;
573 if (ic_myaddr == NONE)
574 ic_myaddr = tip;
575 ic_servaddr = sip;
576 ic_addrservaddr = sip;
577 ic_got_reply = IC_RARP;
578
579 drop_unlock:
580 /* Show's over. Nothing to see here. */
581 spin_unlock(&ic_recv_lock);
582
583 drop:
584 /* Throw the packet out. */
585 kfree_skb(skb);
586 return 0;
587 }
588
589
590 /*
591 * Send RARP request packet over a single interface.
592 */
ic_rarp_send_if(struct ic_device * d)593 static void __init ic_rarp_send_if(struct ic_device *d)
594 {
595 struct net_device *dev = d->dev;
596 arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
597 dev->dev_addr, dev->dev_addr);
598 }
599 #endif
600
601 /*
602 * Predefine Nameservers
603 */
ic_nameservers_predef(void)604 static inline void __init ic_nameservers_predef(void)
605 {
606 int i;
607
608 for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
609 ic_nameservers[i] = NONE;
610 }
611
612 /* Predefine NTP servers */
ic_ntp_servers_predef(void)613 static inline void __init ic_ntp_servers_predef(void)
614 {
615 int i;
616
617 for (i = 0; i < CONF_NTP_SERVERS_MAX; i++)
618 ic_ntp_servers[i] = NONE;
619 }
620
621 /*
622 * DHCP/BOOTP support.
623 */
624
625 #ifdef IPCONFIG_BOOTP
626
627 struct bootp_pkt { /* BOOTP packet format */
628 struct iphdr iph; /* IP header */
629 struct udphdr udph; /* UDP header */
630 u8 op; /* 1=request, 2=reply */
631 u8 htype; /* HW address type */
632 u8 hlen; /* HW address length */
633 u8 hops; /* Used only by gateways */
634 __be32 xid; /* Transaction ID */
635 __be16 secs; /* Seconds since we started */
636 __be16 flags; /* Just what it says */
637 __be32 client_ip; /* Client's IP address if known */
638 __be32 your_ip; /* Assigned IP address */
639 __be32 server_ip; /* (Next, e.g. NFS) Server's IP address */
640 __be32 relay_ip; /* IP address of BOOTP relay */
641 u8 hw_addr[16]; /* Client's HW address */
642 u8 serv_name[64]; /* Server host name */
643 u8 boot_file[128]; /* Name of boot file */
644 u8 exten[312]; /* DHCP options / BOOTP vendor extensions */
645 };
646
647 /* packet ops */
648 #define BOOTP_REQUEST 1
649 #define BOOTP_REPLY 2
650
651 /* DHCP message types */
652 #define DHCPDISCOVER 1
653 #define DHCPOFFER 2
654 #define DHCPREQUEST 3
655 #define DHCPDECLINE 4
656 #define DHCPACK 5
657 #define DHCPNAK 6
658 #define DHCPRELEASE 7
659 #define DHCPINFORM 8
660
661 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
662
663 static struct packet_type bootp_packet_type __initdata = {
664 .type = cpu_to_be16(ETH_P_IP),
665 .func = ic_bootp_recv,
666 };
667
668 /* DHCPACK can overwrite DNS if fallback was set upon first BOOTP reply */
669 static int ic_nameservers_fallback __initdata;
670
671 /*
672 * Initialize DHCP/BOOTP extension fields in the request.
673 */
674
675 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
676
677 #ifdef IPCONFIG_DHCP
678
679 static bool __init
ic_dhcp_add_option(u8 ** options,const u8 * end,u8 type,const void * value,int len)680 ic_dhcp_add_option(u8 **options, const u8 *end, u8 type, const void *value,
681 int len)
682 {
683 u8 *e = *options;
684
685 /* leave room for the option header and the END marker */
686 if (len > U8_MAX || end - e < len + 3)
687 return false;
688
689 *e++ = type;
690 *e++ = len;
691 memcpy(e, value, len);
692 *options = e + len;
693
694 return true;
695 }
696
697 static void __init
ic_dhcp_init_options(u8 * options,struct ic_device * d)698 ic_dhcp_init_options(u8 *options, struct ic_device *d)
699 {
700 static const u8 ic_req_params[] = {
701 1, /* Subnet mask */
702 3, /* Default gateway */
703 6, /* DNS server */
704 12, /* Host name */
705 15, /* Domain name */
706 17, /* Boot path */
707 26, /* MTU */
708 40, /* NIS domain name */
709 42, /* NTP servers */
710 };
711 u8 mt = (ic_servaddr == NONE) ? DHCPDISCOVER : DHCPREQUEST;
712 u8 *end = options + sizeof(((struct bootp_pkt *)0)->exten);
713 u8 *e = options;
714 int len;
715
716 pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
717
718 memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */
719 e += 4;
720
721 *e++ = 53; /* DHCP message type */
722 *e++ = 1;
723 *e++ = mt;
724
725 if (mt == DHCPREQUEST) {
726 *e++ = 54; /* Server ID (IP address) */
727 *e++ = 4;
728 memcpy(e, &ic_servaddr, 4);
729 e += 4;
730
731 *e++ = 50; /* Requested IP address */
732 *e++ = 4;
733 memcpy(e, &ic_myaddr, 4);
734 e += 4;
735 }
736
737 *e++ = 55; /* Parameter request list */
738 *e++ = sizeof(ic_req_params);
739 memcpy(e, ic_req_params, sizeof(ic_req_params));
740 e += sizeof(ic_req_params);
741
742 if (ic_host_name_set) {
743 len = strlen(utsname()->nodename);
744 ic_dhcp_add_option(&e, end, 12, utsname()->nodename, len);
745 }
746 if (*vendor_class_identifier) {
747 len = strlen(vendor_class_identifier);
748 if (ic_dhcp_add_option(&e, end, 60, vendor_class_identifier, len))
749 pr_info("DHCP: sending class identifier \"%s\"\n",
750 vendor_class_identifier);
751 }
752 len = strlen(dhcp_client_identifier + 1);
753 /* the minimum length of identifier is 2, include 1 byte type */
754 if (len >= 1)
755 ic_dhcp_add_option(&e, end, 61, dhcp_client_identifier, len + 1);
756
757 *e++ = 255; /* End of the list */
758 }
759
760 #endif /* IPCONFIG_DHCP */
761
ic_bootp_init_ext(u8 * e)762 static void __init ic_bootp_init_ext(u8 *e)
763 {
764 memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */
765 e += 4;
766 *e++ = 1; /* Subnet mask request */
767 *e++ = 4;
768 e += 4;
769 *e++ = 3; /* Default gateway request */
770 *e++ = 4;
771 e += 4;
772 #if CONF_NAMESERVERS_MAX > 0
773 *e++ = 6; /* (DNS) name server request */
774 *e++ = 4 * CONF_NAMESERVERS_MAX;
775 e += 4 * CONF_NAMESERVERS_MAX;
776 #endif
777 *e++ = 12; /* Host name request */
778 *e++ = 32;
779 e += 32;
780 *e++ = 40; /* NIS Domain name request */
781 *e++ = 32;
782 e += 32;
783 *e++ = 17; /* Boot path */
784 *e++ = 40;
785 e += 40;
786
787 *e++ = 57; /* set extension buffer size for reply */
788 *e++ = 2;
789 *e++ = 1; /* 128+236+8+20+14, see dhcpd sources */
790 *e++ = 150;
791
792 *e++ = 255; /* End of the list */
793 }
794
795
796 /*
797 * Initialize the DHCP/BOOTP mechanism.
798 */
ic_bootp_init(void)799 static inline void __init ic_bootp_init(void)
800 {
801 /* Re-initialise all name servers and NTP servers to NONE, in case any
802 * were set via the "ip=" or "nfsaddrs=" kernel command line parameters:
803 * any IP addresses specified there will already have been decoded but
804 * are no longer needed
805 */
806 ic_nameservers_predef();
807 ic_ntp_servers_predef();
808
809 dev_add_pack(&bootp_packet_type);
810 }
811
812
813 /*
814 * DHCP/BOOTP cleanup.
815 */
ic_bootp_cleanup(void)816 static inline void __init ic_bootp_cleanup(void)
817 {
818 dev_remove_pack(&bootp_packet_type);
819 }
820
821
822 /*
823 * Send DHCP/BOOTP request to single interface.
824 */
ic_bootp_send_if(struct ic_device * d,unsigned long jiffies_diff)825 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
826 {
827 struct net_device *dev = d->dev;
828 struct sk_buff *skb;
829 struct bootp_pkt *b;
830 struct iphdr *h;
831 int hlen = LL_RESERVED_SPACE(dev);
832 int tlen = dev->needed_tailroom;
833
834 /* Allocate packet */
835 skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
836 GFP_KERNEL);
837 if (!skb)
838 return;
839 skb_reserve(skb, hlen);
840 b = skb_put_zero(skb, sizeof(struct bootp_pkt));
841
842 /* Construct IP header */
843 skb_reset_network_header(skb);
844 h = ip_hdr(skb);
845 h->version = 4;
846 h->ihl = 5;
847 h->tot_len = htons(sizeof(struct bootp_pkt));
848 h->frag_off = htons(IP_DF);
849 h->ttl = 64;
850 h->protocol = IPPROTO_UDP;
851 h->daddr = htonl(INADDR_BROADCAST);
852 h->check = ip_fast_csum((unsigned char *) h, h->ihl);
853
854 /* Construct UDP header */
855 b->udph.source = htons(68);
856 b->udph.dest = htons(67);
857 udp_set_len_short(&b->udph, sizeof(struct bootp_pkt) - sizeof(struct iphdr));
858 /* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
859
860 /* Construct DHCP/BOOTP header */
861 b->op = BOOTP_REQUEST;
862 if (dev->type < 256) /* check for false types */
863 b->htype = dev->type;
864 else if (dev->type == ARPHRD_FDDI)
865 b->htype = ARPHRD_ETHER;
866 else {
867 pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
868 dev->name);
869 b->htype = dev->type; /* can cause undefined behavior */
870 }
871
872 /* server_ip and your_ip address are both already zero per RFC2131 */
873 b->hlen = dev->addr_len;
874 memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
875 b->secs = htons(jiffies_diff / HZ);
876 b->xid = d->xid;
877
878 /* add DHCP options or BOOTP extensions */
879 #ifdef IPCONFIG_DHCP
880 if (ic_proto_enabled & IC_USE_DHCP)
881 ic_dhcp_init_options(b->exten, d);
882 else
883 #endif
884 ic_bootp_init_ext(b->exten);
885
886 /* Chain packet down the line... */
887 skb->dev = dev;
888 skb->protocol = htons(ETH_P_IP);
889 if (dev_hard_header(skb, dev, ntohs(skb->protocol),
890 dev->broadcast, dev->dev_addr, skb->len) < 0) {
891 kfree_skb(skb);
892 printk("E");
893 return;
894 }
895
896 if (dev_queue_xmit(skb) < 0)
897 printk("E");
898 }
899
900
901 /*
902 * Copy BOOTP-supplied string
903 */
ic_bootp_string(char * dest,char * src,int len,int max)904 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
905 {
906 if (!len)
907 return 0;
908 if (len > max-1)
909 len = max-1;
910 memcpy(dest, src, len);
911 dest[len] = '\0';
912 return 1;
913 }
914
915
916 /*
917 * Process BOOTP extensions.
918 */
ic_do_bootp_ext(u8 * ext)919 static void __init ic_do_bootp_ext(u8 *ext)
920 {
921 u8 servers;
922 int i;
923 __be16 mtu;
924
925 u8 *c;
926
927 pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
928 for (c=ext+2; c<ext+2+ext[1]; c++)
929 pr_debug(" %02x", *c);
930 pr_debug("\n");
931
932 switch (*ext++) {
933 case 1: /* Subnet mask */
934 if (ic_netmask == NONE)
935 memcpy(&ic_netmask, ext+1, 4);
936 break;
937 case 3: /* Default gateway */
938 if (ic_gateway == NONE)
939 memcpy(&ic_gateway, ext+1, 4);
940 break;
941 case 6: /* DNS server */
942 servers= *ext/4;
943 if (servers > CONF_NAMESERVERS_MAX)
944 servers = CONF_NAMESERVERS_MAX;
945 for (i = 0; i < servers; i++) {
946 if (ic_nameservers[i] == NONE ||
947 ic_nameservers_fallback)
948 memcpy(&ic_nameservers[i], ext+1+4*i, 4);
949 }
950 break;
951 case 12: /* Host name */
952 if (!ic_host_name_set) {
953 ic_bootp_string(utsname()->nodename, ext+1, *ext,
954 __NEW_UTS_LEN);
955 ic_host_name_set = 1;
956 }
957 break;
958 case 15: /* Domain name (DNS) */
959 if (!ic_domain[0])
960 ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
961 break;
962 case 17: /* Root path */
963 if (!root_server_path[0])
964 ic_bootp_string(root_server_path, ext+1, *ext,
965 sizeof(root_server_path));
966 break;
967 case 26: /* Interface MTU */
968 memcpy(&mtu, ext+1, sizeof(mtu));
969 ic_dev_mtu = ntohs(mtu);
970 break;
971 case 40: /* NIS Domain name (_not_ DNS) */
972 ic_bootp_string(utsname()->domainname, ext+1, *ext,
973 __NEW_UTS_LEN);
974 break;
975 case 42: /* NTP servers */
976 servers = *ext / 4;
977 if (servers > CONF_NTP_SERVERS_MAX)
978 servers = CONF_NTP_SERVERS_MAX;
979 for (i = 0; i < servers; i++) {
980 if (ic_ntp_servers[i] == NONE)
981 memcpy(&ic_ntp_servers[i], ext+1+4*i, 4);
982 }
983 break;
984 }
985 }
986
987
988 /*
989 * Receive BOOTP reply.
990 */
ic_bootp_recv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)991 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
992 {
993 struct bootp_pkt *b;
994 struct iphdr *h;
995 struct ic_device *d;
996 int len, ext_len;
997
998 if (!net_eq(dev_net(dev), &init_net))
999 goto drop;
1000
1001 /* Perform verifications before taking the lock. */
1002 if (skb->pkt_type == PACKET_OTHERHOST)
1003 goto drop;
1004
1005 skb = skb_share_check(skb, GFP_ATOMIC);
1006 if (!skb)
1007 return NET_RX_DROP;
1008
1009 if (!pskb_may_pull(skb,
1010 sizeof(struct iphdr) +
1011 sizeof(struct udphdr)))
1012 goto drop;
1013
1014 b = (struct bootp_pkt *)skb_network_header(skb);
1015 h = &b->iph;
1016
1017 if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
1018 goto drop;
1019
1020 /* Fragments are not supported */
1021 if (ip_is_fragment(h)) {
1022 net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
1023 goto drop;
1024 }
1025
1026 if (skb->len < ntohs(h->tot_len))
1027 goto drop;
1028
1029 if (ip_fast_csum((char *) h, h->ihl))
1030 goto drop;
1031
1032 if (b->udph.source != htons(67) || b->udph.dest != htons(68))
1033 goto drop;
1034
1035 if (ntohs(h->tot_len) < udp_get_len_short(&b->udph) + sizeof(struct iphdr))
1036 goto drop;
1037
1038 len = udp_get_len_short(&b->udph) - sizeof(struct udphdr);
1039 ext_len = len - (sizeof(*b) -
1040 sizeof(struct iphdr) -
1041 sizeof(struct udphdr) -
1042 sizeof(b->exten));
1043 if (ext_len < 0)
1044 goto drop;
1045
1046 /* Ok the front looks good, make sure we can get at the rest. */
1047 if (!pskb_may_pull(skb, skb->len))
1048 goto drop;
1049
1050 b = (struct bootp_pkt *)skb_network_header(skb);
1051 h = &b->iph;
1052
1053 /* One reply at a time, please. */
1054 spin_lock(&ic_recv_lock);
1055
1056 /* If we already have a reply, just drop the packet */
1057 if (ic_got_reply)
1058 goto drop_unlock;
1059
1060 /* Find the ic_device that the packet arrived on */
1061 d = ic_first_dev;
1062 while (d && d->dev != dev)
1063 d = d->next;
1064 if (!d)
1065 goto drop_unlock; /* should never happen */
1066
1067 /* Is it a reply to our BOOTP request? */
1068 if (b->op != BOOTP_REPLY ||
1069 b->xid != d->xid) {
1070 net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1071 d->dev->name, b->op, b->xid);
1072 goto drop_unlock;
1073 }
1074
1075 /* Parse extensions */
1076 if (ext_len >= 4 &&
1077 !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1078 u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1079 u8 *ext;
1080
1081 #ifdef IPCONFIG_DHCP
1082 if (ic_proto_enabled & IC_USE_DHCP) {
1083 __be32 server_id = NONE;
1084 int mt = 0;
1085
1086 ext = &b->exten[4];
1087 while (ext < end && *ext != 0xff) {
1088 u8 *opt = ext++;
1089 if (*opt == 0) /* Padding */
1090 continue;
1091 ext += *ext + 1;
1092 if (ext >= end)
1093 break;
1094 switch (*opt) {
1095 case 53: /* Message type */
1096 if (opt[1])
1097 mt = opt[2];
1098 break;
1099 case 54: /* Server ID (IP address) */
1100 if (opt[1] >= 4)
1101 memcpy(&server_id, opt + 2, 4);
1102 break;
1103 }
1104 }
1105
1106 pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1107
1108 switch (mt) {
1109 case DHCPOFFER:
1110 /* While in the process of accepting one offer,
1111 * ignore all others.
1112 */
1113 if (ic_myaddr != NONE)
1114 goto drop_unlock;
1115
1116 /* Let's accept that offer. */
1117 ic_myaddr = b->your_ip;
1118 ic_servaddr = server_id;
1119 pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1120 &ic_myaddr, &b->iph.saddr);
1121 /* The DHCP indicated server address takes
1122 * precedence over the bootp header one if
1123 * they are different.
1124 */
1125 if ((server_id != NONE) &&
1126 (b->server_ip != server_id))
1127 b->server_ip = ic_servaddr;
1128 break;
1129
1130 case DHCPACK:
1131 if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1132 goto drop_unlock;
1133
1134 /* Yeah! */
1135 break;
1136
1137 default:
1138 /* Urque. Forget it*/
1139 ic_myaddr = NONE;
1140 ic_servaddr = NONE;
1141 goto drop_unlock;
1142 }
1143
1144 ic_dhcp_msgtype = mt;
1145
1146 }
1147 #endif /* IPCONFIG_DHCP */
1148
1149 ext = &b->exten[4];
1150 while (ext < end && *ext != 0xff) {
1151 u8 *opt = ext++;
1152 if (*opt == 0) /* Padding */
1153 continue;
1154 ext += *ext + 1;
1155 if (ext < end)
1156 ic_do_bootp_ext(opt);
1157 }
1158 }
1159
1160 /* We have a winner! */
1161 ic_dev = d;
1162 ic_myaddr = b->your_ip;
1163 ic_servaddr = b->server_ip;
1164 ic_addrservaddr = b->iph.saddr;
1165 if (ic_gateway == NONE && b->relay_ip)
1166 ic_gateway = b->relay_ip;
1167 if (ic_nameservers[0] == NONE) {
1168 ic_nameservers[0] = ic_servaddr;
1169 ic_nameservers_fallback = 1;
1170 }
1171 ic_got_reply = IC_BOOTP;
1172
1173 drop_unlock:
1174 /* Show's over. Nothing to see here. */
1175 spin_unlock(&ic_recv_lock);
1176
1177 drop:
1178 /* Throw the packet out. */
1179 kfree_skb(skb);
1180
1181 return 0;
1182 }
1183
1184
1185 #endif
1186
1187
1188 /*
1189 * Dynamic IP configuration -- DHCP, BOOTP, RARP.
1190 */
1191
1192 #ifdef IPCONFIG_DYNAMIC
1193
ic_dynamic(void)1194 static int __init ic_dynamic(void)
1195 {
1196 int retries;
1197 struct ic_device *d;
1198 unsigned long start_jiffies, timeout, jiff;
1199 int do_bootp = ic_proto_have_if & IC_BOOTP;
1200 int do_rarp = ic_proto_have_if & IC_RARP;
1201
1202 /*
1203 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1204 * This routine gets only called when some pieces of information
1205 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1206 */
1207 if (!ic_proto_enabled) {
1208 pr_err("IP-Config: Incomplete network configuration information\n");
1209 return -1;
1210 }
1211
1212 #ifdef IPCONFIG_BOOTP
1213 if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1214 pr_err("DHCP/BOOTP: No suitable device found\n");
1215 #endif
1216 #ifdef IPCONFIG_RARP
1217 if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1218 pr_err("RARP: No suitable device found\n");
1219 #endif
1220
1221 if (!ic_proto_have_if)
1222 /* Error message already printed */
1223 return -1;
1224
1225 /*
1226 * Setup protocols
1227 */
1228 #ifdef IPCONFIG_BOOTP
1229 if (do_bootp)
1230 ic_bootp_init();
1231 #endif
1232 #ifdef IPCONFIG_RARP
1233 if (do_rarp)
1234 ic_rarp_init();
1235 #endif
1236
1237 /*
1238 * Send requests and wait, until we get an answer. This loop
1239 * seems to be a terrible waste of CPU time, but actually there is
1240 * only one process running at all, so we don't need to use any
1241 * scheduler functions.
1242 * [Actually we could now, but the nothing else running note still
1243 * applies.. - AC]
1244 */
1245 pr_notice("Sending %s%s%s requests .",
1246 do_bootp
1247 ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1248 (do_bootp && do_rarp) ? " and " : "",
1249 do_rarp ? "RARP" : "");
1250
1251 start_jiffies = jiffies;
1252 d = ic_first_dev;
1253 retries = CONF_SEND_RETRIES;
1254 get_random_bytes(&timeout, sizeof(timeout));
1255 timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1256 for (;;) {
1257 #ifdef IPCONFIG_BOOTP
1258 if (do_bootp && (d->able & IC_BOOTP))
1259 ic_bootp_send_if(d, jiffies - start_jiffies);
1260 #endif
1261 #ifdef IPCONFIG_RARP
1262 if (do_rarp && (d->able & IC_RARP))
1263 ic_rarp_send_if(d);
1264 #endif
1265
1266 if (!d->next) {
1267 jiff = jiffies + timeout;
1268 while (time_before(jiffies, jiff) && !ic_got_reply)
1269 schedule_timeout_uninterruptible(1);
1270 }
1271 #ifdef IPCONFIG_DHCP
1272 /* DHCP isn't done until we get a DHCPACK. */
1273 if ((ic_got_reply & IC_BOOTP) &&
1274 (ic_proto_enabled & IC_USE_DHCP) &&
1275 ic_dhcp_msgtype != DHCPACK) {
1276 ic_got_reply = 0;
1277 /* continue on device that got the reply */
1278 d = ic_dev;
1279 pr_cont(",");
1280 continue;
1281 }
1282 #endif /* IPCONFIG_DHCP */
1283
1284 if (ic_got_reply) {
1285 pr_cont(" OK\n");
1286 break;
1287 }
1288
1289 if ((d = d->next))
1290 continue;
1291
1292 if (! --retries) {
1293 pr_cont(" timed out!\n");
1294 break;
1295 }
1296
1297 d = ic_first_dev;
1298
1299 timeout = timeout CONF_TIMEOUT_MULT;
1300 if (timeout > CONF_TIMEOUT_MAX)
1301 timeout = CONF_TIMEOUT_MAX;
1302
1303 pr_cont(".");
1304 }
1305
1306 #ifdef IPCONFIG_BOOTP
1307 if (do_bootp)
1308 ic_bootp_cleanup();
1309 #endif
1310 #ifdef IPCONFIG_RARP
1311 if (do_rarp)
1312 ic_rarp_cleanup();
1313 #endif
1314
1315 if (!ic_got_reply) {
1316 ic_myaddr = NONE;
1317 return -1;
1318 }
1319
1320 pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1321 ((ic_got_reply & IC_RARP) ? "RARP"
1322 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1323 &ic_addrservaddr, &ic_myaddr);
1324
1325 return 0;
1326 }
1327
1328 #endif /* IPCONFIG_DYNAMIC */
1329
1330 #ifdef CONFIG_PROC_FS
1331 /* proc_dir_entry for /proc/net/ipconfig */
1332 static struct proc_dir_entry *ipconfig_dir;
1333
1334 /* Name servers: */
pnp_seq_show(struct seq_file * seq,void * v)1335 static int pnp_seq_show(struct seq_file *seq, void *v)
1336 {
1337 int i;
1338
1339 if (ic_proto_used & IC_PROTO)
1340 seq_printf(seq, "#PROTO: %s\n",
1341 (ic_proto_used & IC_RARP) ? "RARP"
1342 : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1343 else
1344 seq_puts(seq, "#MANUAL\n");
1345
1346 if (ic_domain[0])
1347 seq_printf(seq,
1348 "domain %s\n", ic_domain);
1349 for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1350 if (ic_nameservers[i] != NONE)
1351 seq_printf(seq, "nameserver %pI4\n",
1352 &ic_nameservers[i]);
1353 }
1354 if (ic_servaddr != NONE)
1355 seq_printf(seq, "bootserver %pI4\n",
1356 &ic_servaddr);
1357 return 0;
1358 }
1359
1360 /* Create the /proc/net/ipconfig directory */
ipconfig_proc_net_init(void)1361 static int __init ipconfig_proc_net_init(void)
1362 {
1363 ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net);
1364 if (!ipconfig_dir)
1365 return -ENOMEM;
1366
1367 return 0;
1368 }
1369
1370 /* Create a new file under /proc/net/ipconfig */
ipconfig_proc_net_create(const char * name,const struct proc_ops * proc_ops)1371 static int ipconfig_proc_net_create(const char *name,
1372 const struct proc_ops *proc_ops)
1373 {
1374 char *pname;
1375 struct proc_dir_entry *p;
1376
1377 if (!ipconfig_dir)
1378 return -ENOMEM;
1379
1380 pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name);
1381 if (!pname)
1382 return -ENOMEM;
1383
1384 p = proc_create(pname, 0444, init_net.proc_net, proc_ops);
1385 kfree(pname);
1386 if (!p)
1387 return -ENOMEM;
1388
1389 return 0;
1390 }
1391
1392 /* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */
ntp_servers_show(struct seq_file * seq,void * v)1393 static int ntp_servers_show(struct seq_file *seq, void *v)
1394 {
1395 int i;
1396
1397 for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1398 if (ic_ntp_servers[i] != NONE)
1399 seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]);
1400 }
1401 return 0;
1402 }
1403 DEFINE_PROC_SHOW_ATTRIBUTE(ntp_servers);
1404 #endif /* CONFIG_PROC_FS */
1405
1406 /*
1407 * Extract IP address from the parameter string if needed. Note that we
1408 * need to have root_server_addr set _before_ IPConfig gets called as it
1409 * can override it.
1410 */
root_nfs_parse_addr(char * name)1411 __be32 __init root_nfs_parse_addr(char *name)
1412 {
1413 __be32 addr;
1414 int octets = 0;
1415 char *cp, *cq;
1416
1417 cp = cq = name;
1418 while (octets < 4) {
1419 while (*cp >= '0' && *cp <= '9')
1420 cp++;
1421 if (cp == cq || cp - cq > 3)
1422 break;
1423 if (*cp == '.' || octets == 3)
1424 octets++;
1425 if (octets < 4)
1426 cp++;
1427 cq = cp;
1428 }
1429 if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1430 if (*cp == ':')
1431 *cp++ = '\0';
1432 addr = in_aton(name);
1433 memmove(name, cp, strlen(cp) + 1);
1434 } else
1435 addr = NONE;
1436
1437 return addr;
1438 }
1439
1440 #define DEVICE_WAIT_MAX 12 /* 12 seconds */
1441
wait_for_devices(void)1442 static int __init wait_for_devices(void)
1443 {
1444 int i;
1445 bool try_init_devs = true;
1446
1447 for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1448 struct net_device *dev;
1449 int found = 0;
1450
1451 /* make sure deferred device probes are finished */
1452 wait_for_device_probe();
1453
1454 rtnl_lock();
1455 for_each_netdev(&init_net, dev) {
1456 if (ic_is_init_dev(dev)) {
1457 found = 1;
1458 break;
1459 }
1460 }
1461 rtnl_unlock();
1462 if (found)
1463 return 0;
1464 if (try_init_devs &&
1465 (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) {
1466 try_init_devs = false;
1467 wait_for_init_devices_probe();
1468 }
1469 ssleep(1);
1470 }
1471 return -ENODEV;
1472 }
1473
1474 /*
1475 * IP Autoconfig dispatcher.
1476 */
1477
ip_auto_config(void)1478 static int __init ip_auto_config(void)
1479 {
1480 __be32 addr;
1481 #ifdef IPCONFIG_DYNAMIC
1482 int retries = CONF_OPEN_RETRIES;
1483 #endif
1484 int err;
1485 unsigned int i, count;
1486
1487 /* Initialise all name servers and NTP servers to NONE (but only if the
1488 * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded,
1489 * otherwise we'll overwrite the IP addresses specified there)
1490 */
1491 if (ic_set_manually == 0) {
1492 ic_nameservers_predef();
1493 ic_ntp_servers_predef();
1494 }
1495
1496 #ifdef CONFIG_PROC_FS
1497 proc_create_single("pnp", 0444, init_net.proc_net, pnp_seq_show);
1498
1499 if (ipconfig_proc_net_init() == 0)
1500 ipconfig_proc_net_create("ntp_servers", &ntp_servers_proc_ops);
1501 #endif /* CONFIG_PROC_FS */
1502
1503 if (!ic_enable)
1504 return 0;
1505
1506 pr_debug("IP-Config: Entered.\n");
1507 #ifdef IPCONFIG_DYNAMIC
1508 try_try_again:
1509 #endif
1510 /* Wait for devices to appear */
1511 err = wait_for_devices();
1512 if (err)
1513 return err;
1514
1515 /* Setup all network devices */
1516 err = ic_open_devs();
1517 if (err)
1518 return err;
1519
1520 /* Give drivers a chance to settle */
1521 msleep(CONF_POST_OPEN);
1522
1523 /*
1524 * If the config information is insufficient (e.g., our IP address or
1525 * IP address of the boot server is missing or we have multiple network
1526 * interfaces and no default was set), use BOOTP or RARP to get the
1527 * missing values.
1528 */
1529 if (ic_myaddr == NONE ||
1530 #if defined(CONFIG_ROOT_NFS) || defined(CONFIG_CIFS_ROOT)
1531 (root_server_addr == NONE &&
1532 ic_servaddr == NONE &&
1533 (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) ||
1534 #endif
1535 ic_first_dev->next) {
1536 #ifdef IPCONFIG_DYNAMIC
1537 if (ic_dynamic() < 0) {
1538 ic_close_devs();
1539
1540 /*
1541 * I don't know why, but sometimes the
1542 * eepro100 driver (at least) gets upset and
1543 * doesn't work the first time it's opened.
1544 * But then if you close it and reopen it, it
1545 * works just fine. So we need to try that at
1546 * least once before giving up.
1547 *
1548 * Also, if the root will be NFS-mounted, we
1549 * have nowhere to go if DHCP fails. So we
1550 * just have to keep trying forever.
1551 *
1552 * -- Chip
1553 */
1554 #ifdef CONFIG_ROOT_NFS
1555 if (ROOT_DEV == Root_NFS) {
1556 pr_err("IP-Config: Retrying forever (NFS root)...\n");
1557 goto try_try_again;
1558 }
1559 #endif
1560 #ifdef CONFIG_CIFS_ROOT
1561 if (ROOT_DEV == Root_CIFS) {
1562 pr_err("IP-Config: Retrying forever (CIFS root)...\n");
1563 goto try_try_again;
1564 }
1565 #endif
1566
1567 if (--retries) {
1568 pr_err("IP-Config: Reopening network devices...\n");
1569 goto try_try_again;
1570 }
1571
1572 /* Oh, well. At least we tried. */
1573 pr_err("IP-Config: Auto-configuration of network failed\n");
1574 return -1;
1575 }
1576 #else /* !DYNAMIC */
1577 pr_err("IP-Config: Incomplete network configuration information\n");
1578 ic_close_devs();
1579 return -1;
1580 #endif /* IPCONFIG_DYNAMIC */
1581 } else {
1582 /* Device selected manually or only one device -> use it */
1583 ic_dev = ic_first_dev;
1584 }
1585
1586 addr = root_nfs_parse_addr(root_server_path);
1587 if (root_server_addr == NONE)
1588 root_server_addr = addr;
1589
1590 /*
1591 * Use defaults wherever applicable.
1592 */
1593 if (ic_defaults() < 0)
1594 return -1;
1595
1596 /*
1597 * Record which protocol was actually used.
1598 */
1599 #ifdef IPCONFIG_DYNAMIC
1600 ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1601 #endif
1602
1603 #ifndef IPCONFIG_SILENT
1604 /*
1605 * Clue in the operator.
1606 */
1607 pr_info("IP-Config: Complete:\n");
1608
1609 pr_info(" device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1610 ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1611 &ic_myaddr, &ic_netmask, &ic_gateway);
1612 pr_info(" host=%s, domain=%s, nis-domain=%s\n",
1613 utsname()->nodename, ic_domain, utsname()->domainname);
1614 pr_info(" bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1615 &ic_servaddr, &root_server_addr, root_server_path);
1616 if (ic_dev_mtu)
1617 pr_cont(", mtu=%d", ic_dev_mtu);
1618 /* Name servers (if any): */
1619 for (i = 0, count = 0; i < CONF_NAMESERVERS_MAX; i++) {
1620 if (ic_nameservers[i] != NONE) {
1621 if (i == 0)
1622 pr_info(" nameserver%u=%pI4",
1623 i, &ic_nameservers[i]);
1624 else
1625 pr_cont(", nameserver%u=%pI4",
1626 i, &ic_nameservers[i]);
1627
1628 count++;
1629 }
1630 if ((i + 1 == CONF_NAMESERVERS_MAX) && count > 0)
1631 pr_cont("\n");
1632 }
1633 /* NTP servers (if any): */
1634 for (i = 0, count = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1635 if (ic_ntp_servers[i] != NONE) {
1636 if (i == 0)
1637 pr_info(" ntpserver%u=%pI4",
1638 i, &ic_ntp_servers[i]);
1639 else
1640 pr_cont(", ntpserver%u=%pI4",
1641 i, &ic_ntp_servers[i]);
1642
1643 count++;
1644 }
1645 if ((i + 1 == CONF_NTP_SERVERS_MAX) && count > 0)
1646 pr_cont("\n");
1647 }
1648 #endif /* !SILENT */
1649
1650 /*
1651 * Close all network devices except the device we've
1652 * autoconfigured and set up routes.
1653 */
1654 if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1655 err = -1;
1656 else
1657 err = 0;
1658
1659 ic_close_devs();
1660
1661 return err;
1662 }
1663
1664 late_initcall(ip_auto_config);
1665
1666
1667 /*
1668 * Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1669 * command line parameter. See Documentation/admin-guide/nfs/nfsroot.rst.
1670 */
ic_proto_name(char * name)1671 static int __init ic_proto_name(char *name)
1672 {
1673 if (!strcmp(name, "on") || !strcmp(name, "any")) {
1674 return 1;
1675 }
1676 if (!strcmp(name, "off") || !strcmp(name, "none")) {
1677 return 0;
1678 }
1679 #ifdef CONFIG_IP_PNP_DHCP
1680 else if (!strncmp(name, "dhcp", 4)) {
1681 char *client_id;
1682
1683 ic_proto_enabled &= ~IC_RARP;
1684 client_id = strstr(name, "dhcp,");
1685 if (client_id) {
1686 char *v;
1687
1688 client_id = client_id + 5;
1689 v = strchr(client_id, ',');
1690 if (!v)
1691 return 1;
1692 *v = 0;
1693 if (kstrtou8(client_id, 0, dhcp_client_identifier))
1694 pr_debug("DHCP: Invalid client identifier type\n");
1695 strscpy(dhcp_client_identifier + 1, v + 1,
1696 sizeof(dhcp_client_identifier) - 1);
1697 *v = ',';
1698 }
1699 return 1;
1700 }
1701 #endif
1702 #ifdef CONFIG_IP_PNP_BOOTP
1703 else if (!strcmp(name, "bootp")) {
1704 ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1705 return 1;
1706 }
1707 #endif
1708 #ifdef CONFIG_IP_PNP_RARP
1709 else if (!strcmp(name, "rarp")) {
1710 ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1711 return 1;
1712 }
1713 #endif
1714 #ifdef IPCONFIG_DYNAMIC
1715 else if (!strcmp(name, "both")) {
1716 ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1717 return 1;
1718 }
1719 #endif
1720 return 0;
1721 }
1722
ip_auto_config_setup(char * addrs)1723 static int __init ip_auto_config_setup(char *addrs)
1724 {
1725 char *cp, *ip, *dp;
1726 int num = 0;
1727
1728 ic_set_manually = 1;
1729 ic_enable = 1;
1730
1731 /*
1732 * If any dhcp, bootp etc options are set, leave autoconfig on
1733 * and skip the below static IP processing.
1734 */
1735 if (ic_proto_name(addrs))
1736 return 1;
1737
1738 /* If no static IP is given, turn off autoconfig and bail. */
1739 if (*addrs == 0 ||
1740 strcmp(addrs, "off") == 0 ||
1741 strcmp(addrs, "none") == 0) {
1742 ic_enable = 0;
1743 return 1;
1744 }
1745
1746 /* Initialise all name servers and NTP servers to NONE */
1747 ic_nameservers_predef();
1748 ic_ntp_servers_predef();
1749
1750 /* Parse string for static IP assignment. */
1751 ip = addrs;
1752 while (ip && *ip) {
1753 if ((cp = strchr(ip, ':')))
1754 *cp++ = '\0';
1755 if (strlen(ip) > 0) {
1756 pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1757 switch (num) {
1758 case 0:
1759 if ((ic_myaddr = in_aton(ip)) == ANY)
1760 ic_myaddr = NONE;
1761 break;
1762 case 1:
1763 if ((ic_servaddr = in_aton(ip)) == ANY)
1764 ic_servaddr = NONE;
1765 break;
1766 case 2:
1767 if ((ic_gateway = in_aton(ip)) == ANY)
1768 ic_gateway = NONE;
1769 break;
1770 case 3:
1771 if ((ic_netmask = in_aton(ip)) == ANY)
1772 ic_netmask = NONE;
1773 break;
1774 case 4:
1775 if ((dp = strchr(ip, '.'))) {
1776 *dp++ = '\0';
1777 strscpy(utsname()->domainname, dp,
1778 sizeof(utsname()->domainname));
1779 }
1780 strscpy(utsname()->nodename, ip,
1781 sizeof(utsname()->nodename));
1782 ic_host_name_set = 1;
1783 break;
1784 case 5:
1785 strscpy(user_dev_name, ip, sizeof(user_dev_name));
1786 break;
1787 case 6:
1788 if (ic_proto_name(ip) == 0 &&
1789 ic_myaddr == NONE) {
1790 ic_enable = 0;
1791 }
1792 break;
1793 case 7:
1794 if (CONF_NAMESERVERS_MAX >= 1) {
1795 ic_nameservers[0] = in_aton(ip);
1796 if (ic_nameservers[0] == ANY)
1797 ic_nameservers[0] = NONE;
1798 }
1799 break;
1800 case 8:
1801 if (CONF_NAMESERVERS_MAX >= 2) {
1802 ic_nameservers[1] = in_aton(ip);
1803 if (ic_nameservers[1] == ANY)
1804 ic_nameservers[1] = NONE;
1805 }
1806 break;
1807 case 9:
1808 if (CONF_NTP_SERVERS_MAX >= 1) {
1809 ic_ntp_servers[0] = in_aton(ip);
1810 if (ic_ntp_servers[0] == ANY)
1811 ic_ntp_servers[0] = NONE;
1812 }
1813 break;
1814 }
1815 }
1816 ip = cp;
1817 num++;
1818 }
1819
1820 return 1;
1821 }
1822 __setup("ip=", ip_auto_config_setup);
1823
nfsaddrs_config_setup(char * addrs)1824 static int __init nfsaddrs_config_setup(char *addrs)
1825 {
1826 return ip_auto_config_setup(addrs);
1827 }
1828 __setup("nfsaddrs=", nfsaddrs_config_setup);
1829
vendor_class_identifier_setup(char * addrs)1830 static int __init vendor_class_identifier_setup(char *addrs)
1831 {
1832 if (strscpy(vendor_class_identifier, addrs,
1833 sizeof(vendor_class_identifier))
1834 >= sizeof(vendor_class_identifier))
1835 pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1836 vendor_class_identifier);
1837 return 1;
1838 }
1839 __setup("dhcpclass=", vendor_class_identifier_setup);
1840
set_carrier_timeout(char * str)1841 static int __init set_carrier_timeout(char *str)
1842 {
1843 ssize_t ret;
1844
1845 if (!str)
1846 return 0;
1847
1848 ret = kstrtouint(str, 0, &carrier_timeout);
1849 if (ret)
1850 return 0;
1851
1852 return 1;
1853 }
1854 __setup("carrier_timeout=", set_carrier_timeout);
1855