xref: /openbmc/linux/net/ipv4/devinet.c (revision b627b4ed)
1 /*
2  *	NET3	IP device support routines.
3  *
4  *		This program is free software; you can redistribute it and/or
5  *		modify it under the terms of the GNU General Public License
6  *		as published by the Free Software Foundation; either version
7  *		2 of the License, or (at your option) any later version.
8  *
9  *	Derived from the IP parts of dev.c 1.0.19
10  * 		Authors:	Ross Biro
11  *				Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12  *				Mark Evans, <evansmp@uhura.aston.ac.uk>
13  *
14  *	Additional Authors:
15  *		Alan Cox, <gw4pts@gw4pts.ampr.org>
16  *		Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
17  *
18  *	Changes:
19  *		Alexey Kuznetsov:	pa_* fields are replaced with ifaddr
20  *					lists.
21  *		Cyrus Durgin:		updated for kmod
22  *		Matthias Andree:	in devinet_ioctl, compare label and
23  *					address (4.4BSD alias style support),
24  *					fall back to comparing just the label
25  *					if no match found.
26  */
27 
28 
29 #include <asm/uaccess.h>
30 #include <asm/system.h>
31 #include <linux/bitops.h>
32 #include <linux/capability.h>
33 #include <linux/module.h>
34 #include <linux/types.h>
35 #include <linux/kernel.h>
36 #include <linux/string.h>
37 #include <linux/mm.h>
38 #include <linux/socket.h>
39 #include <linux/sockios.h>
40 #include <linux/in.h>
41 #include <linux/errno.h>
42 #include <linux/interrupt.h>
43 #include <linux/if_addr.h>
44 #include <linux/if_ether.h>
45 #include <linux/inet.h>
46 #include <linux/netdevice.h>
47 #include <linux/etherdevice.h>
48 #include <linux/skbuff.h>
49 #include <linux/init.h>
50 #include <linux/notifier.h>
51 #include <linux/inetdevice.h>
52 #include <linux/igmp.h>
53 #ifdef CONFIG_SYSCTL
54 #include <linux/sysctl.h>
55 #endif
56 #include <linux/kmod.h>
57 
58 #include <net/arp.h>
59 #include <net/ip.h>
60 #include <net/route.h>
61 #include <net/ip_fib.h>
62 #include <net/rtnetlink.h>
63 #include <net/net_namespace.h>
64 
65 static struct ipv4_devconf ipv4_devconf = {
66 	.data = {
67 		[NET_IPV4_CONF_ACCEPT_REDIRECTS - 1] = 1,
68 		[NET_IPV4_CONF_SEND_REDIRECTS - 1] = 1,
69 		[NET_IPV4_CONF_SECURE_REDIRECTS - 1] = 1,
70 		[NET_IPV4_CONF_SHARED_MEDIA - 1] = 1,
71 	},
72 };
73 
74 static struct ipv4_devconf ipv4_devconf_dflt = {
75 	.data = {
76 		[NET_IPV4_CONF_ACCEPT_REDIRECTS - 1] = 1,
77 		[NET_IPV4_CONF_SEND_REDIRECTS - 1] = 1,
78 		[NET_IPV4_CONF_SECURE_REDIRECTS - 1] = 1,
79 		[NET_IPV4_CONF_SHARED_MEDIA - 1] = 1,
80 		[NET_IPV4_CONF_ACCEPT_SOURCE_ROUTE - 1] = 1,
81 	},
82 };
83 
84 #define IPV4_DEVCONF_DFLT(net, attr) \
85 	IPV4_DEVCONF((*net->ipv4.devconf_dflt), attr)
86 
87 static const struct nla_policy ifa_ipv4_policy[IFA_MAX+1] = {
88 	[IFA_LOCAL]     	= { .type = NLA_U32 },
89 	[IFA_ADDRESS]   	= { .type = NLA_U32 },
90 	[IFA_BROADCAST] 	= { .type = NLA_U32 },
91 	[IFA_LABEL]     	= { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
92 };
93 
94 static void rtmsg_ifa(int event, struct in_ifaddr *, struct nlmsghdr *, u32);
95 
96 static BLOCKING_NOTIFIER_HEAD(inetaddr_chain);
97 static void inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
98 			 int destroy);
99 #ifdef CONFIG_SYSCTL
100 static void devinet_sysctl_register(struct in_device *idev);
101 static void devinet_sysctl_unregister(struct in_device *idev);
102 #else
103 static inline void devinet_sysctl_register(struct in_device *idev)
104 {
105 }
106 static inline void devinet_sysctl_unregister(struct in_device *idev)
107 {
108 }
109 #endif
110 
111 /* Locks all the inet devices. */
112 
113 static struct in_ifaddr *inet_alloc_ifa(void)
114 {
115 	return kzalloc(sizeof(struct in_ifaddr), GFP_KERNEL);
116 }
117 
118 static void inet_rcu_free_ifa(struct rcu_head *head)
119 {
120 	struct in_ifaddr *ifa = container_of(head, struct in_ifaddr, rcu_head);
121 	if (ifa->ifa_dev)
122 		in_dev_put(ifa->ifa_dev);
123 	kfree(ifa);
124 }
125 
126 static inline void inet_free_ifa(struct in_ifaddr *ifa)
127 {
128 	call_rcu(&ifa->rcu_head, inet_rcu_free_ifa);
129 }
130 
131 void in_dev_finish_destroy(struct in_device *idev)
132 {
133 	struct net_device *dev = idev->dev;
134 
135 	WARN_ON(idev->ifa_list);
136 	WARN_ON(idev->mc_list);
137 #ifdef NET_REFCNT_DEBUG
138 	printk(KERN_DEBUG "in_dev_finish_destroy: %p=%s\n",
139 	       idev, dev ? dev->name : "NIL");
140 #endif
141 	dev_put(dev);
142 	if (!idev->dead)
143 		printk("Freeing alive in_device %p\n", idev);
144 	else {
145 		kfree(idev);
146 	}
147 }
148 
149 static struct in_device *inetdev_init(struct net_device *dev)
150 {
151 	struct in_device *in_dev;
152 
153 	ASSERT_RTNL();
154 
155 	in_dev = kzalloc(sizeof(*in_dev), GFP_KERNEL);
156 	if (!in_dev)
157 		goto out;
158 	memcpy(&in_dev->cnf, dev_net(dev)->ipv4.devconf_dflt,
159 			sizeof(in_dev->cnf));
160 	in_dev->cnf.sysctl = NULL;
161 	in_dev->dev = dev;
162 	if ((in_dev->arp_parms = neigh_parms_alloc(dev, &arp_tbl)) == NULL)
163 		goto out_kfree;
164 	if (IPV4_DEVCONF(in_dev->cnf, FORWARDING))
165 		dev_disable_lro(dev);
166 	/* Reference in_dev->dev */
167 	dev_hold(dev);
168 	/* Account for reference dev->ip_ptr (below) */
169 	in_dev_hold(in_dev);
170 
171 	devinet_sysctl_register(in_dev);
172 	ip_mc_init_dev(in_dev);
173 	if (dev->flags & IFF_UP)
174 		ip_mc_up(in_dev);
175 
176 	/* we can receive as soon as ip_ptr is set -- do this last */
177 	rcu_assign_pointer(dev->ip_ptr, in_dev);
178 out:
179 	return in_dev;
180 out_kfree:
181 	kfree(in_dev);
182 	in_dev = NULL;
183 	goto out;
184 }
185 
186 static void in_dev_rcu_put(struct rcu_head *head)
187 {
188 	struct in_device *idev = container_of(head, struct in_device, rcu_head);
189 	in_dev_put(idev);
190 }
191 
192 static void inetdev_destroy(struct in_device *in_dev)
193 {
194 	struct in_ifaddr *ifa;
195 	struct net_device *dev;
196 
197 	ASSERT_RTNL();
198 
199 	dev = in_dev->dev;
200 
201 	in_dev->dead = 1;
202 
203 	ip_mc_destroy_dev(in_dev);
204 
205 	while ((ifa = in_dev->ifa_list) != NULL) {
206 		inet_del_ifa(in_dev, &in_dev->ifa_list, 0);
207 		inet_free_ifa(ifa);
208 	}
209 
210 	dev->ip_ptr = NULL;
211 
212 	devinet_sysctl_unregister(in_dev);
213 	neigh_parms_release(&arp_tbl, in_dev->arp_parms);
214 	arp_ifdown(dev);
215 
216 	call_rcu(&in_dev->rcu_head, in_dev_rcu_put);
217 }
218 
219 int inet_addr_onlink(struct in_device *in_dev, __be32 a, __be32 b)
220 {
221 	rcu_read_lock();
222 	for_primary_ifa(in_dev) {
223 		if (inet_ifa_match(a, ifa)) {
224 			if (!b || inet_ifa_match(b, ifa)) {
225 				rcu_read_unlock();
226 				return 1;
227 			}
228 		}
229 	} endfor_ifa(in_dev);
230 	rcu_read_unlock();
231 	return 0;
232 }
233 
234 static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
235 			 int destroy, struct nlmsghdr *nlh, u32 pid)
236 {
237 	struct in_ifaddr *promote = NULL;
238 	struct in_ifaddr *ifa, *ifa1 = *ifap;
239 	struct in_ifaddr *last_prim = in_dev->ifa_list;
240 	struct in_ifaddr *prev_prom = NULL;
241 	int do_promote = IN_DEV_PROMOTE_SECONDARIES(in_dev);
242 
243 	ASSERT_RTNL();
244 
245 	/* 1. Deleting primary ifaddr forces deletion all secondaries
246 	 * unless alias promotion is set
247 	 **/
248 
249 	if (!(ifa1->ifa_flags & IFA_F_SECONDARY)) {
250 		struct in_ifaddr **ifap1 = &ifa1->ifa_next;
251 
252 		while ((ifa = *ifap1) != NULL) {
253 			if (!(ifa->ifa_flags & IFA_F_SECONDARY) &&
254 			    ifa1->ifa_scope <= ifa->ifa_scope)
255 				last_prim = ifa;
256 
257 			if (!(ifa->ifa_flags & IFA_F_SECONDARY) ||
258 			    ifa1->ifa_mask != ifa->ifa_mask ||
259 			    !inet_ifa_match(ifa1->ifa_address, ifa)) {
260 				ifap1 = &ifa->ifa_next;
261 				prev_prom = ifa;
262 				continue;
263 			}
264 
265 			if (!do_promote) {
266 				*ifap1 = ifa->ifa_next;
267 
268 				rtmsg_ifa(RTM_DELADDR, ifa, nlh, pid);
269 				blocking_notifier_call_chain(&inetaddr_chain,
270 						NETDEV_DOWN, ifa);
271 				inet_free_ifa(ifa);
272 			} else {
273 				promote = ifa;
274 				break;
275 			}
276 		}
277 	}
278 
279 	/* 2. Unlink it */
280 
281 	*ifap = ifa1->ifa_next;
282 
283 	/* 3. Announce address deletion */
284 
285 	/* Send message first, then call notifier.
286 	   At first sight, FIB update triggered by notifier
287 	   will refer to already deleted ifaddr, that could confuse
288 	   netlink listeners. It is not true: look, gated sees
289 	   that route deleted and if it still thinks that ifaddr
290 	   is valid, it will try to restore deleted routes... Grr.
291 	   So that, this order is correct.
292 	 */
293 	rtmsg_ifa(RTM_DELADDR, ifa1, nlh, pid);
294 	blocking_notifier_call_chain(&inetaddr_chain, NETDEV_DOWN, ifa1);
295 
296 	if (promote) {
297 
298 		if (prev_prom) {
299 			prev_prom->ifa_next = promote->ifa_next;
300 			promote->ifa_next = last_prim->ifa_next;
301 			last_prim->ifa_next = promote;
302 		}
303 
304 		promote->ifa_flags &= ~IFA_F_SECONDARY;
305 		rtmsg_ifa(RTM_NEWADDR, promote, nlh, pid);
306 		blocking_notifier_call_chain(&inetaddr_chain,
307 				NETDEV_UP, promote);
308 		for (ifa = promote->ifa_next; ifa; ifa = ifa->ifa_next) {
309 			if (ifa1->ifa_mask != ifa->ifa_mask ||
310 			    !inet_ifa_match(ifa1->ifa_address, ifa))
311 					continue;
312 			fib_add_ifaddr(ifa);
313 		}
314 
315 	}
316 	if (destroy)
317 		inet_free_ifa(ifa1);
318 }
319 
320 static void inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
321 			 int destroy)
322 {
323 	__inet_del_ifa(in_dev, ifap, destroy, NULL, 0);
324 }
325 
326 static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh,
327 			     u32 pid)
328 {
329 	struct in_device *in_dev = ifa->ifa_dev;
330 	struct in_ifaddr *ifa1, **ifap, **last_primary;
331 
332 	ASSERT_RTNL();
333 
334 	if (!ifa->ifa_local) {
335 		inet_free_ifa(ifa);
336 		return 0;
337 	}
338 
339 	ifa->ifa_flags &= ~IFA_F_SECONDARY;
340 	last_primary = &in_dev->ifa_list;
341 
342 	for (ifap = &in_dev->ifa_list; (ifa1 = *ifap) != NULL;
343 	     ifap = &ifa1->ifa_next) {
344 		if (!(ifa1->ifa_flags & IFA_F_SECONDARY) &&
345 		    ifa->ifa_scope <= ifa1->ifa_scope)
346 			last_primary = &ifa1->ifa_next;
347 		if (ifa1->ifa_mask == ifa->ifa_mask &&
348 		    inet_ifa_match(ifa1->ifa_address, ifa)) {
349 			if (ifa1->ifa_local == ifa->ifa_local) {
350 				inet_free_ifa(ifa);
351 				return -EEXIST;
352 			}
353 			if (ifa1->ifa_scope != ifa->ifa_scope) {
354 				inet_free_ifa(ifa);
355 				return -EINVAL;
356 			}
357 			ifa->ifa_flags |= IFA_F_SECONDARY;
358 		}
359 	}
360 
361 	if (!(ifa->ifa_flags & IFA_F_SECONDARY)) {
362 		net_srandom(ifa->ifa_local);
363 		ifap = last_primary;
364 	}
365 
366 	ifa->ifa_next = *ifap;
367 	*ifap = ifa;
368 
369 	/* Send message first, then call notifier.
370 	   Notifier will trigger FIB update, so that
371 	   listeners of netlink will know about new ifaddr */
372 	rtmsg_ifa(RTM_NEWADDR, ifa, nlh, pid);
373 	blocking_notifier_call_chain(&inetaddr_chain, NETDEV_UP, ifa);
374 
375 	return 0;
376 }
377 
378 static int inet_insert_ifa(struct in_ifaddr *ifa)
379 {
380 	return __inet_insert_ifa(ifa, NULL, 0);
381 }
382 
383 static int inet_set_ifa(struct net_device *dev, struct in_ifaddr *ifa)
384 {
385 	struct in_device *in_dev = __in_dev_get_rtnl(dev);
386 
387 	ASSERT_RTNL();
388 
389 	if (!in_dev) {
390 		inet_free_ifa(ifa);
391 		return -ENOBUFS;
392 	}
393 	ipv4_devconf_setall(in_dev);
394 	if (ifa->ifa_dev != in_dev) {
395 		WARN_ON(ifa->ifa_dev);
396 		in_dev_hold(in_dev);
397 		ifa->ifa_dev = in_dev;
398 	}
399 	if (ipv4_is_loopback(ifa->ifa_local))
400 		ifa->ifa_scope = RT_SCOPE_HOST;
401 	return inet_insert_ifa(ifa);
402 }
403 
404 struct in_device *inetdev_by_index(struct net *net, int ifindex)
405 {
406 	struct net_device *dev;
407 	struct in_device *in_dev = NULL;
408 	read_lock(&dev_base_lock);
409 	dev = __dev_get_by_index(net, ifindex);
410 	if (dev)
411 		in_dev = in_dev_get(dev);
412 	read_unlock(&dev_base_lock);
413 	return in_dev;
414 }
415 
416 /* Called only from RTNL semaphored context. No locks. */
417 
418 struct in_ifaddr *inet_ifa_byprefix(struct in_device *in_dev, __be32 prefix,
419 				    __be32 mask)
420 {
421 	ASSERT_RTNL();
422 
423 	for_primary_ifa(in_dev) {
424 		if (ifa->ifa_mask == mask && inet_ifa_match(prefix, ifa))
425 			return ifa;
426 	} endfor_ifa(in_dev);
427 	return NULL;
428 }
429 
430 static int inet_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
431 {
432 	struct net *net = sock_net(skb->sk);
433 	struct nlattr *tb[IFA_MAX+1];
434 	struct in_device *in_dev;
435 	struct ifaddrmsg *ifm;
436 	struct in_ifaddr *ifa, **ifap;
437 	int err = -EINVAL;
438 
439 	ASSERT_RTNL();
440 
441 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv4_policy);
442 	if (err < 0)
443 		goto errout;
444 
445 	ifm = nlmsg_data(nlh);
446 	in_dev = inetdev_by_index(net, ifm->ifa_index);
447 	if (in_dev == NULL) {
448 		err = -ENODEV;
449 		goto errout;
450 	}
451 
452 	__in_dev_put(in_dev);
453 
454 	for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
455 	     ifap = &ifa->ifa_next) {
456 		if (tb[IFA_LOCAL] &&
457 		    ifa->ifa_local != nla_get_be32(tb[IFA_LOCAL]))
458 			continue;
459 
460 		if (tb[IFA_LABEL] && nla_strcmp(tb[IFA_LABEL], ifa->ifa_label))
461 			continue;
462 
463 		if (tb[IFA_ADDRESS] &&
464 		    (ifm->ifa_prefixlen != ifa->ifa_prefixlen ||
465 		    !inet_ifa_match(nla_get_be32(tb[IFA_ADDRESS]), ifa)))
466 			continue;
467 
468 		__inet_del_ifa(in_dev, ifap, 1, nlh, NETLINK_CB(skb).pid);
469 		return 0;
470 	}
471 
472 	err = -EADDRNOTAVAIL;
473 errout:
474 	return err;
475 }
476 
477 static struct in_ifaddr *rtm_to_ifaddr(struct net *net, struct nlmsghdr *nlh)
478 {
479 	struct nlattr *tb[IFA_MAX+1];
480 	struct in_ifaddr *ifa;
481 	struct ifaddrmsg *ifm;
482 	struct net_device *dev;
483 	struct in_device *in_dev;
484 	int err;
485 
486 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv4_policy);
487 	if (err < 0)
488 		goto errout;
489 
490 	ifm = nlmsg_data(nlh);
491 	err = -EINVAL;
492 	if (ifm->ifa_prefixlen > 32 || tb[IFA_LOCAL] == NULL)
493 		goto errout;
494 
495 	dev = __dev_get_by_index(net, ifm->ifa_index);
496 	err = -ENODEV;
497 	if (dev == NULL)
498 		goto errout;
499 
500 	in_dev = __in_dev_get_rtnl(dev);
501 	err = -ENOBUFS;
502 	if (in_dev == NULL)
503 		goto errout;
504 
505 	ifa = inet_alloc_ifa();
506 	if (ifa == NULL)
507 		/*
508 		 * A potential indev allocation can be left alive, it stays
509 		 * assigned to its device and is destroy with it.
510 		 */
511 		goto errout;
512 
513 	ipv4_devconf_setall(in_dev);
514 	in_dev_hold(in_dev);
515 
516 	if (tb[IFA_ADDRESS] == NULL)
517 		tb[IFA_ADDRESS] = tb[IFA_LOCAL];
518 
519 	ifa->ifa_prefixlen = ifm->ifa_prefixlen;
520 	ifa->ifa_mask = inet_make_mask(ifm->ifa_prefixlen);
521 	ifa->ifa_flags = ifm->ifa_flags;
522 	ifa->ifa_scope = ifm->ifa_scope;
523 	ifa->ifa_dev = in_dev;
524 
525 	ifa->ifa_local = nla_get_be32(tb[IFA_LOCAL]);
526 	ifa->ifa_address = nla_get_be32(tb[IFA_ADDRESS]);
527 
528 	if (tb[IFA_BROADCAST])
529 		ifa->ifa_broadcast = nla_get_be32(tb[IFA_BROADCAST]);
530 
531 	if (tb[IFA_LABEL])
532 		nla_strlcpy(ifa->ifa_label, tb[IFA_LABEL], IFNAMSIZ);
533 	else
534 		memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
535 
536 	return ifa;
537 
538 errout:
539 	return ERR_PTR(err);
540 }
541 
542 static int inet_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
543 {
544 	struct net *net = sock_net(skb->sk);
545 	struct in_ifaddr *ifa;
546 
547 	ASSERT_RTNL();
548 
549 	ifa = rtm_to_ifaddr(net, nlh);
550 	if (IS_ERR(ifa))
551 		return PTR_ERR(ifa);
552 
553 	return __inet_insert_ifa(ifa, nlh, NETLINK_CB(skb).pid);
554 }
555 
556 /*
557  *	Determine a default network mask, based on the IP address.
558  */
559 
560 static __inline__ int inet_abc_len(__be32 addr)
561 {
562 	int rc = -1;	/* Something else, probably a multicast. */
563 
564 	if (ipv4_is_zeronet(addr))
565 		rc = 0;
566 	else {
567 		__u32 haddr = ntohl(addr);
568 
569 		if (IN_CLASSA(haddr))
570 			rc = 8;
571 		else if (IN_CLASSB(haddr))
572 			rc = 16;
573 		else if (IN_CLASSC(haddr))
574 			rc = 24;
575 	}
576 
577 	return rc;
578 }
579 
580 
581 int devinet_ioctl(struct net *net, unsigned int cmd, void __user *arg)
582 {
583 	struct ifreq ifr;
584 	struct sockaddr_in sin_orig;
585 	struct sockaddr_in *sin = (struct sockaddr_in *)&ifr.ifr_addr;
586 	struct in_device *in_dev;
587 	struct in_ifaddr **ifap = NULL;
588 	struct in_ifaddr *ifa = NULL;
589 	struct net_device *dev;
590 	char *colon;
591 	int ret = -EFAULT;
592 	int tryaddrmatch = 0;
593 
594 	/*
595 	 *	Fetch the caller's info block into kernel space
596 	 */
597 
598 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
599 		goto out;
600 	ifr.ifr_name[IFNAMSIZ - 1] = 0;
601 
602 	/* save original address for comparison */
603 	memcpy(&sin_orig, sin, sizeof(*sin));
604 
605 	colon = strchr(ifr.ifr_name, ':');
606 	if (colon)
607 		*colon = 0;
608 
609 	dev_load(net, ifr.ifr_name);
610 
611 	switch (cmd) {
612 	case SIOCGIFADDR:	/* Get interface address */
613 	case SIOCGIFBRDADDR:	/* Get the broadcast address */
614 	case SIOCGIFDSTADDR:	/* Get the destination address */
615 	case SIOCGIFNETMASK:	/* Get the netmask for the interface */
616 		/* Note that these ioctls will not sleep,
617 		   so that we do not impose a lock.
618 		   One day we will be forced to put shlock here (I mean SMP)
619 		 */
620 		tryaddrmatch = (sin_orig.sin_family == AF_INET);
621 		memset(sin, 0, sizeof(*sin));
622 		sin->sin_family = AF_INET;
623 		break;
624 
625 	case SIOCSIFFLAGS:
626 		ret = -EACCES;
627 		if (!capable(CAP_NET_ADMIN))
628 			goto out;
629 		break;
630 	case SIOCSIFADDR:	/* Set interface address (and family) */
631 	case SIOCSIFBRDADDR:	/* Set the broadcast address */
632 	case SIOCSIFDSTADDR:	/* Set the destination address */
633 	case SIOCSIFNETMASK: 	/* Set the netmask for the interface */
634 		ret = -EACCES;
635 		if (!capable(CAP_NET_ADMIN))
636 			goto out;
637 		ret = -EINVAL;
638 		if (sin->sin_family != AF_INET)
639 			goto out;
640 		break;
641 	default:
642 		ret = -EINVAL;
643 		goto out;
644 	}
645 
646 	rtnl_lock();
647 
648 	ret = -ENODEV;
649 	if ((dev = __dev_get_by_name(net, ifr.ifr_name)) == NULL)
650 		goto done;
651 
652 	if (colon)
653 		*colon = ':';
654 
655 	if ((in_dev = __in_dev_get_rtnl(dev)) != NULL) {
656 		if (tryaddrmatch) {
657 			/* Matthias Andree */
658 			/* compare label and address (4.4BSD style) */
659 			/* note: we only do this for a limited set of ioctls
660 			   and only if the original address family was AF_INET.
661 			   This is checked above. */
662 			for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
663 			     ifap = &ifa->ifa_next) {
664 				if (!strcmp(ifr.ifr_name, ifa->ifa_label) &&
665 				    sin_orig.sin_addr.s_addr ==
666 							ifa->ifa_address) {
667 					break; /* found */
668 				}
669 			}
670 		}
671 		/* we didn't get a match, maybe the application is
672 		   4.3BSD-style and passed in junk so we fall back to
673 		   comparing just the label */
674 		if (!ifa) {
675 			for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
676 			     ifap = &ifa->ifa_next)
677 				if (!strcmp(ifr.ifr_name, ifa->ifa_label))
678 					break;
679 		}
680 	}
681 
682 	ret = -EADDRNOTAVAIL;
683 	if (!ifa && cmd != SIOCSIFADDR && cmd != SIOCSIFFLAGS)
684 		goto done;
685 
686 	switch (cmd) {
687 	case SIOCGIFADDR:	/* Get interface address */
688 		sin->sin_addr.s_addr = ifa->ifa_local;
689 		goto rarok;
690 
691 	case SIOCGIFBRDADDR:	/* Get the broadcast address */
692 		sin->sin_addr.s_addr = ifa->ifa_broadcast;
693 		goto rarok;
694 
695 	case SIOCGIFDSTADDR:	/* Get the destination address */
696 		sin->sin_addr.s_addr = ifa->ifa_address;
697 		goto rarok;
698 
699 	case SIOCGIFNETMASK:	/* Get the netmask for the interface */
700 		sin->sin_addr.s_addr = ifa->ifa_mask;
701 		goto rarok;
702 
703 	case SIOCSIFFLAGS:
704 		if (colon) {
705 			ret = -EADDRNOTAVAIL;
706 			if (!ifa)
707 				break;
708 			ret = 0;
709 			if (!(ifr.ifr_flags & IFF_UP))
710 				inet_del_ifa(in_dev, ifap, 1);
711 			break;
712 		}
713 		ret = dev_change_flags(dev, ifr.ifr_flags);
714 		break;
715 
716 	case SIOCSIFADDR:	/* Set interface address (and family) */
717 		ret = -EINVAL;
718 		if (inet_abc_len(sin->sin_addr.s_addr) < 0)
719 			break;
720 
721 		if (!ifa) {
722 			ret = -ENOBUFS;
723 			if ((ifa = inet_alloc_ifa()) == NULL)
724 				break;
725 			if (colon)
726 				memcpy(ifa->ifa_label, ifr.ifr_name, IFNAMSIZ);
727 			else
728 				memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
729 		} else {
730 			ret = 0;
731 			if (ifa->ifa_local == sin->sin_addr.s_addr)
732 				break;
733 			inet_del_ifa(in_dev, ifap, 0);
734 			ifa->ifa_broadcast = 0;
735 			ifa->ifa_scope = 0;
736 		}
737 
738 		ifa->ifa_address = ifa->ifa_local = sin->sin_addr.s_addr;
739 
740 		if (!(dev->flags & IFF_POINTOPOINT)) {
741 			ifa->ifa_prefixlen = inet_abc_len(ifa->ifa_address);
742 			ifa->ifa_mask = inet_make_mask(ifa->ifa_prefixlen);
743 			if ((dev->flags & IFF_BROADCAST) &&
744 			    ifa->ifa_prefixlen < 31)
745 				ifa->ifa_broadcast = ifa->ifa_address |
746 						     ~ifa->ifa_mask;
747 		} else {
748 			ifa->ifa_prefixlen = 32;
749 			ifa->ifa_mask = inet_make_mask(32);
750 		}
751 		ret = inet_set_ifa(dev, ifa);
752 		break;
753 
754 	case SIOCSIFBRDADDR:	/* Set the broadcast address */
755 		ret = 0;
756 		if (ifa->ifa_broadcast != sin->sin_addr.s_addr) {
757 			inet_del_ifa(in_dev, ifap, 0);
758 			ifa->ifa_broadcast = sin->sin_addr.s_addr;
759 			inet_insert_ifa(ifa);
760 		}
761 		break;
762 
763 	case SIOCSIFDSTADDR:	/* Set the destination address */
764 		ret = 0;
765 		if (ifa->ifa_address == sin->sin_addr.s_addr)
766 			break;
767 		ret = -EINVAL;
768 		if (inet_abc_len(sin->sin_addr.s_addr) < 0)
769 			break;
770 		ret = 0;
771 		inet_del_ifa(in_dev, ifap, 0);
772 		ifa->ifa_address = sin->sin_addr.s_addr;
773 		inet_insert_ifa(ifa);
774 		break;
775 
776 	case SIOCSIFNETMASK: 	/* Set the netmask for the interface */
777 
778 		/*
779 		 *	The mask we set must be legal.
780 		 */
781 		ret = -EINVAL;
782 		if (bad_mask(sin->sin_addr.s_addr, 0))
783 			break;
784 		ret = 0;
785 		if (ifa->ifa_mask != sin->sin_addr.s_addr) {
786 			__be32 old_mask = ifa->ifa_mask;
787 			inet_del_ifa(in_dev, ifap, 0);
788 			ifa->ifa_mask = sin->sin_addr.s_addr;
789 			ifa->ifa_prefixlen = inet_mask_len(ifa->ifa_mask);
790 
791 			/* See if current broadcast address matches
792 			 * with current netmask, then recalculate
793 			 * the broadcast address. Otherwise it's a
794 			 * funny address, so don't touch it since
795 			 * the user seems to know what (s)he's doing...
796 			 */
797 			if ((dev->flags & IFF_BROADCAST) &&
798 			    (ifa->ifa_prefixlen < 31) &&
799 			    (ifa->ifa_broadcast ==
800 			     (ifa->ifa_local|~old_mask))) {
801 				ifa->ifa_broadcast = (ifa->ifa_local |
802 						      ~sin->sin_addr.s_addr);
803 			}
804 			inet_insert_ifa(ifa);
805 		}
806 		break;
807 	}
808 done:
809 	rtnl_unlock();
810 out:
811 	return ret;
812 rarok:
813 	rtnl_unlock();
814 	ret = copy_to_user(arg, &ifr, sizeof(struct ifreq)) ? -EFAULT : 0;
815 	goto out;
816 }
817 
818 static int inet_gifconf(struct net_device *dev, char __user *buf, int len)
819 {
820 	struct in_device *in_dev = __in_dev_get_rtnl(dev);
821 	struct in_ifaddr *ifa;
822 	struct ifreq ifr;
823 	int done = 0;
824 
825 	if (!in_dev || (ifa = in_dev->ifa_list) == NULL)
826 		goto out;
827 
828 	for (; ifa; ifa = ifa->ifa_next) {
829 		if (!buf) {
830 			done += sizeof(ifr);
831 			continue;
832 		}
833 		if (len < (int) sizeof(ifr))
834 			break;
835 		memset(&ifr, 0, sizeof(struct ifreq));
836 		if (ifa->ifa_label)
837 			strcpy(ifr.ifr_name, ifa->ifa_label);
838 		else
839 			strcpy(ifr.ifr_name, dev->name);
840 
841 		(*(struct sockaddr_in *)&ifr.ifr_addr).sin_family = AF_INET;
842 		(*(struct sockaddr_in *)&ifr.ifr_addr).sin_addr.s_addr =
843 								ifa->ifa_local;
844 
845 		if (copy_to_user(buf, &ifr, sizeof(struct ifreq))) {
846 			done = -EFAULT;
847 			break;
848 		}
849 		buf  += sizeof(struct ifreq);
850 		len  -= sizeof(struct ifreq);
851 		done += sizeof(struct ifreq);
852 	}
853 out:
854 	return done;
855 }
856 
857 __be32 inet_select_addr(const struct net_device *dev, __be32 dst, int scope)
858 {
859 	__be32 addr = 0;
860 	struct in_device *in_dev;
861 	struct net *net = dev_net(dev);
862 
863 	rcu_read_lock();
864 	in_dev = __in_dev_get_rcu(dev);
865 	if (!in_dev)
866 		goto no_in_dev;
867 
868 	for_primary_ifa(in_dev) {
869 		if (ifa->ifa_scope > scope)
870 			continue;
871 		if (!dst || inet_ifa_match(dst, ifa)) {
872 			addr = ifa->ifa_local;
873 			break;
874 		}
875 		if (!addr)
876 			addr = ifa->ifa_local;
877 	} endfor_ifa(in_dev);
878 no_in_dev:
879 	rcu_read_unlock();
880 
881 	if (addr)
882 		goto out;
883 
884 	/* Not loopback addresses on loopback should be preferred
885 	   in this case. It is importnat that lo is the first interface
886 	   in dev_base list.
887 	 */
888 	read_lock(&dev_base_lock);
889 	rcu_read_lock();
890 	for_each_netdev(net, dev) {
891 		if ((in_dev = __in_dev_get_rcu(dev)) == NULL)
892 			continue;
893 
894 		for_primary_ifa(in_dev) {
895 			if (ifa->ifa_scope != RT_SCOPE_LINK &&
896 			    ifa->ifa_scope <= scope) {
897 				addr = ifa->ifa_local;
898 				goto out_unlock_both;
899 			}
900 		} endfor_ifa(in_dev);
901 	}
902 out_unlock_both:
903 	read_unlock(&dev_base_lock);
904 	rcu_read_unlock();
905 out:
906 	return addr;
907 }
908 
909 static __be32 confirm_addr_indev(struct in_device *in_dev, __be32 dst,
910 			      __be32 local, int scope)
911 {
912 	int same = 0;
913 	__be32 addr = 0;
914 
915 	for_ifa(in_dev) {
916 		if (!addr &&
917 		    (local == ifa->ifa_local || !local) &&
918 		    ifa->ifa_scope <= scope) {
919 			addr = ifa->ifa_local;
920 			if (same)
921 				break;
922 		}
923 		if (!same) {
924 			same = (!local || inet_ifa_match(local, ifa)) &&
925 				(!dst || inet_ifa_match(dst, ifa));
926 			if (same && addr) {
927 				if (local || !dst)
928 					break;
929 				/* Is the selected addr into dst subnet? */
930 				if (inet_ifa_match(addr, ifa))
931 					break;
932 				/* No, then can we use new local src? */
933 				if (ifa->ifa_scope <= scope) {
934 					addr = ifa->ifa_local;
935 					break;
936 				}
937 				/* search for large dst subnet for addr */
938 				same = 0;
939 			}
940 		}
941 	} endfor_ifa(in_dev);
942 
943 	return same? addr : 0;
944 }
945 
946 /*
947  * Confirm that local IP address exists using wildcards:
948  * - in_dev: only on this interface, 0=any interface
949  * - dst: only in the same subnet as dst, 0=any dst
950  * - local: address, 0=autoselect the local address
951  * - scope: maximum allowed scope value for the local address
952  */
953 __be32 inet_confirm_addr(struct in_device *in_dev,
954 			 __be32 dst, __be32 local, int scope)
955 {
956 	__be32 addr = 0;
957 	struct net_device *dev;
958 	struct net *net;
959 
960 	if (scope != RT_SCOPE_LINK)
961 		return confirm_addr_indev(in_dev, dst, local, scope);
962 
963 	net = dev_net(in_dev->dev);
964 	read_lock(&dev_base_lock);
965 	rcu_read_lock();
966 	for_each_netdev(net, dev) {
967 		if ((in_dev = __in_dev_get_rcu(dev))) {
968 			addr = confirm_addr_indev(in_dev, dst, local, scope);
969 			if (addr)
970 				break;
971 		}
972 	}
973 	rcu_read_unlock();
974 	read_unlock(&dev_base_lock);
975 
976 	return addr;
977 }
978 
979 /*
980  *	Device notifier
981  */
982 
983 int register_inetaddr_notifier(struct notifier_block *nb)
984 {
985 	return blocking_notifier_chain_register(&inetaddr_chain, nb);
986 }
987 
988 int unregister_inetaddr_notifier(struct notifier_block *nb)
989 {
990 	return blocking_notifier_chain_unregister(&inetaddr_chain, nb);
991 }
992 
993 /* Rename ifa_labels for a device name change. Make some effort to preserve existing
994  * alias numbering and to create unique labels if possible.
995 */
996 static void inetdev_changename(struct net_device *dev, struct in_device *in_dev)
997 {
998 	struct in_ifaddr *ifa;
999 	int named = 0;
1000 
1001 	for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
1002 		char old[IFNAMSIZ], *dot;
1003 
1004 		memcpy(old, ifa->ifa_label, IFNAMSIZ);
1005 		memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
1006 		if (named++ == 0)
1007 			goto skip;
1008 		dot = strchr(old, ':');
1009 		if (dot == NULL) {
1010 			sprintf(old, ":%d", named);
1011 			dot = old;
1012 		}
1013 		if (strlen(dot) + strlen(dev->name) < IFNAMSIZ) {
1014 			strcat(ifa->ifa_label, dot);
1015 		} else {
1016 			strcpy(ifa->ifa_label + (IFNAMSIZ - strlen(dot) - 1), dot);
1017 		}
1018 skip:
1019 		rtmsg_ifa(RTM_NEWADDR, ifa, NULL, 0);
1020 	}
1021 }
1022 
1023 static inline bool inetdev_valid_mtu(unsigned mtu)
1024 {
1025 	return mtu >= 68;
1026 }
1027 
1028 /* Called only under RTNL semaphore */
1029 
1030 static int inetdev_event(struct notifier_block *this, unsigned long event,
1031 			 void *ptr)
1032 {
1033 	struct net_device *dev = ptr;
1034 	struct in_device *in_dev = __in_dev_get_rtnl(dev);
1035 
1036 	ASSERT_RTNL();
1037 
1038 	if (!in_dev) {
1039 		if (event == NETDEV_REGISTER) {
1040 			in_dev = inetdev_init(dev);
1041 			if (!in_dev)
1042 				return notifier_from_errno(-ENOMEM);
1043 			if (dev->flags & IFF_LOOPBACK) {
1044 				IN_DEV_CONF_SET(in_dev, NOXFRM, 1);
1045 				IN_DEV_CONF_SET(in_dev, NOPOLICY, 1);
1046 			}
1047 		} else if (event == NETDEV_CHANGEMTU) {
1048 			/* Re-enabling IP */
1049 			if (inetdev_valid_mtu(dev->mtu))
1050 				in_dev = inetdev_init(dev);
1051 		}
1052 		goto out;
1053 	}
1054 
1055 	switch (event) {
1056 	case NETDEV_REGISTER:
1057 		printk(KERN_DEBUG "inetdev_event: bug\n");
1058 		dev->ip_ptr = NULL;
1059 		break;
1060 	case NETDEV_UP:
1061 		if (!inetdev_valid_mtu(dev->mtu))
1062 			break;
1063 		if (dev->flags & IFF_LOOPBACK) {
1064 			struct in_ifaddr *ifa;
1065 			if ((ifa = inet_alloc_ifa()) != NULL) {
1066 				ifa->ifa_local =
1067 				  ifa->ifa_address = htonl(INADDR_LOOPBACK);
1068 				ifa->ifa_prefixlen = 8;
1069 				ifa->ifa_mask = inet_make_mask(8);
1070 				in_dev_hold(in_dev);
1071 				ifa->ifa_dev = in_dev;
1072 				ifa->ifa_scope = RT_SCOPE_HOST;
1073 				memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
1074 				inet_insert_ifa(ifa);
1075 			}
1076 		}
1077 		ip_mc_up(in_dev);
1078 		/* fall through */
1079 	case NETDEV_CHANGEADDR:
1080 		if (IN_DEV_ARP_NOTIFY(in_dev))
1081 			arp_send(ARPOP_REQUEST, ETH_P_ARP,
1082 				 in_dev->ifa_list->ifa_address,
1083 				 dev,
1084 				 in_dev->ifa_list->ifa_address,
1085 				 NULL, dev->dev_addr, NULL);
1086 		break;
1087 	case NETDEV_DOWN:
1088 		ip_mc_down(in_dev);
1089 		break;
1090 	case NETDEV_CHANGEMTU:
1091 		if (inetdev_valid_mtu(dev->mtu))
1092 			break;
1093 		/* disable IP when MTU is not enough */
1094 	case NETDEV_UNREGISTER:
1095 		inetdev_destroy(in_dev);
1096 		break;
1097 	case NETDEV_CHANGENAME:
1098 		/* Do not notify about label change, this event is
1099 		 * not interesting to applications using netlink.
1100 		 */
1101 		inetdev_changename(dev, in_dev);
1102 
1103 		devinet_sysctl_unregister(in_dev);
1104 		devinet_sysctl_register(in_dev);
1105 		break;
1106 	}
1107 out:
1108 	return NOTIFY_DONE;
1109 }
1110 
1111 static struct notifier_block ip_netdev_notifier = {
1112 	.notifier_call = inetdev_event,
1113 };
1114 
1115 static inline size_t inet_nlmsg_size(void)
1116 {
1117 	return NLMSG_ALIGN(sizeof(struct ifaddrmsg))
1118 	       + nla_total_size(4) /* IFA_ADDRESS */
1119 	       + nla_total_size(4) /* IFA_LOCAL */
1120 	       + nla_total_size(4) /* IFA_BROADCAST */
1121 	       + nla_total_size(IFNAMSIZ); /* IFA_LABEL */
1122 }
1123 
1124 static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa,
1125 			    u32 pid, u32 seq, int event, unsigned int flags)
1126 {
1127 	struct ifaddrmsg *ifm;
1128 	struct nlmsghdr  *nlh;
1129 
1130 	nlh = nlmsg_put(skb, pid, seq, event, sizeof(*ifm), flags);
1131 	if (nlh == NULL)
1132 		return -EMSGSIZE;
1133 
1134 	ifm = nlmsg_data(nlh);
1135 	ifm->ifa_family = AF_INET;
1136 	ifm->ifa_prefixlen = ifa->ifa_prefixlen;
1137 	ifm->ifa_flags = ifa->ifa_flags|IFA_F_PERMANENT;
1138 	ifm->ifa_scope = ifa->ifa_scope;
1139 	ifm->ifa_index = ifa->ifa_dev->dev->ifindex;
1140 
1141 	if (ifa->ifa_address)
1142 		NLA_PUT_BE32(skb, IFA_ADDRESS, ifa->ifa_address);
1143 
1144 	if (ifa->ifa_local)
1145 		NLA_PUT_BE32(skb, IFA_LOCAL, ifa->ifa_local);
1146 
1147 	if (ifa->ifa_broadcast)
1148 		NLA_PUT_BE32(skb, IFA_BROADCAST, ifa->ifa_broadcast);
1149 
1150 	if (ifa->ifa_label[0])
1151 		NLA_PUT_STRING(skb, IFA_LABEL, ifa->ifa_label);
1152 
1153 	return nlmsg_end(skb, nlh);
1154 
1155 nla_put_failure:
1156 	nlmsg_cancel(skb, nlh);
1157 	return -EMSGSIZE;
1158 }
1159 
1160 static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
1161 {
1162 	struct net *net = sock_net(skb->sk);
1163 	int idx, ip_idx;
1164 	struct net_device *dev;
1165 	struct in_device *in_dev;
1166 	struct in_ifaddr *ifa;
1167 	int s_ip_idx, s_idx = cb->args[0];
1168 
1169 	s_ip_idx = ip_idx = cb->args[1];
1170 	idx = 0;
1171 	for_each_netdev(net, dev) {
1172 		if (idx < s_idx)
1173 			goto cont;
1174 		if (idx > s_idx)
1175 			s_ip_idx = 0;
1176 		if ((in_dev = __in_dev_get_rtnl(dev)) == NULL)
1177 			goto cont;
1178 
1179 		for (ifa = in_dev->ifa_list, ip_idx = 0; ifa;
1180 		     ifa = ifa->ifa_next, ip_idx++) {
1181 			if (ip_idx < s_ip_idx)
1182 				continue;
1183 			if (inet_fill_ifaddr(skb, ifa, NETLINK_CB(cb->skb).pid,
1184 					     cb->nlh->nlmsg_seq,
1185 					     RTM_NEWADDR, NLM_F_MULTI) <= 0)
1186 				goto done;
1187 		}
1188 cont:
1189 		idx++;
1190 	}
1191 
1192 done:
1193 	cb->args[0] = idx;
1194 	cb->args[1] = ip_idx;
1195 
1196 	return skb->len;
1197 }
1198 
1199 static void rtmsg_ifa(int event, struct in_ifaddr *ifa, struct nlmsghdr *nlh,
1200 		      u32 pid)
1201 {
1202 	struct sk_buff *skb;
1203 	u32 seq = nlh ? nlh->nlmsg_seq : 0;
1204 	int err = -ENOBUFS;
1205 	struct net *net;
1206 
1207 	net = dev_net(ifa->ifa_dev->dev);
1208 	skb = nlmsg_new(inet_nlmsg_size(), GFP_KERNEL);
1209 	if (skb == NULL)
1210 		goto errout;
1211 
1212 	err = inet_fill_ifaddr(skb, ifa, pid, seq, event, 0);
1213 	if (err < 0) {
1214 		/* -EMSGSIZE implies BUG in inet_nlmsg_size() */
1215 		WARN_ON(err == -EMSGSIZE);
1216 		kfree_skb(skb);
1217 		goto errout;
1218 	}
1219 	rtnl_notify(skb, net, pid, RTNLGRP_IPV4_IFADDR, nlh, GFP_KERNEL);
1220 	return;
1221 errout:
1222 	if (err < 0)
1223 		rtnl_set_sk_err(net, RTNLGRP_IPV4_IFADDR, err);
1224 }
1225 
1226 #ifdef CONFIG_SYSCTL
1227 
1228 static void devinet_copy_dflt_conf(struct net *net, int i)
1229 {
1230 	struct net_device *dev;
1231 
1232 	read_lock(&dev_base_lock);
1233 	for_each_netdev(net, dev) {
1234 		struct in_device *in_dev;
1235 		rcu_read_lock();
1236 		in_dev = __in_dev_get_rcu(dev);
1237 		if (in_dev && !test_bit(i, in_dev->cnf.state))
1238 			in_dev->cnf.data[i] = net->ipv4.devconf_dflt->data[i];
1239 		rcu_read_unlock();
1240 	}
1241 	read_unlock(&dev_base_lock);
1242 }
1243 
1244 static void inet_forward_change(struct net *net)
1245 {
1246 	struct net_device *dev;
1247 	int on = IPV4_DEVCONF_ALL(net, FORWARDING);
1248 
1249 	IPV4_DEVCONF_ALL(net, ACCEPT_REDIRECTS) = !on;
1250 	IPV4_DEVCONF_DFLT(net, FORWARDING) = on;
1251 
1252 	read_lock(&dev_base_lock);
1253 	for_each_netdev(net, dev) {
1254 		struct in_device *in_dev;
1255 		if (on)
1256 			dev_disable_lro(dev);
1257 		rcu_read_lock();
1258 		in_dev = __in_dev_get_rcu(dev);
1259 		if (in_dev)
1260 			IN_DEV_CONF_SET(in_dev, FORWARDING, on);
1261 		rcu_read_unlock();
1262 	}
1263 	read_unlock(&dev_base_lock);
1264 }
1265 
1266 static int devinet_conf_proc(ctl_table *ctl, int write,
1267 			     struct file *filp, void __user *buffer,
1268 			     size_t *lenp, loff_t *ppos)
1269 {
1270 	int ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
1271 
1272 	if (write) {
1273 		struct ipv4_devconf *cnf = ctl->extra1;
1274 		struct net *net = ctl->extra2;
1275 		int i = (int *)ctl->data - cnf->data;
1276 
1277 		set_bit(i, cnf->state);
1278 
1279 		if (cnf == net->ipv4.devconf_dflt)
1280 			devinet_copy_dflt_conf(net, i);
1281 	}
1282 
1283 	return ret;
1284 }
1285 
1286 static int devinet_conf_sysctl(ctl_table *table,
1287 			       void __user *oldval, size_t __user *oldlenp,
1288 			       void __user *newval, size_t newlen)
1289 {
1290 	struct ipv4_devconf *cnf;
1291 	struct net *net;
1292 	int *valp = table->data;
1293 	int new;
1294 	int i;
1295 
1296 	if (!newval || !newlen)
1297 		return 0;
1298 
1299 	if (newlen != sizeof(int))
1300 		return -EINVAL;
1301 
1302 	if (get_user(new, (int __user *)newval))
1303 		return -EFAULT;
1304 
1305 	if (new == *valp)
1306 		return 0;
1307 
1308 	if (oldval && oldlenp) {
1309 		size_t len;
1310 
1311 		if (get_user(len, oldlenp))
1312 			return -EFAULT;
1313 
1314 		if (len) {
1315 			if (len > table->maxlen)
1316 				len = table->maxlen;
1317 			if (copy_to_user(oldval, valp, len))
1318 				return -EFAULT;
1319 			if (put_user(len, oldlenp))
1320 				return -EFAULT;
1321 		}
1322 	}
1323 
1324 	*valp = new;
1325 
1326 	cnf = table->extra1;
1327 	net = table->extra2;
1328 	i = (int *)table->data - cnf->data;
1329 
1330 	set_bit(i, cnf->state);
1331 
1332 	if (cnf == net->ipv4.devconf_dflt)
1333 		devinet_copy_dflt_conf(net, i);
1334 
1335 	return 1;
1336 }
1337 
1338 static int devinet_sysctl_forward(ctl_table *ctl, int write,
1339 				  struct file *filp, void __user *buffer,
1340 				  size_t *lenp, loff_t *ppos)
1341 {
1342 	int *valp = ctl->data;
1343 	int val = *valp;
1344 	int ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
1345 
1346 	if (write && *valp != val) {
1347 		struct net *net = ctl->extra2;
1348 
1349 		if (valp != &IPV4_DEVCONF_DFLT(net, FORWARDING)) {
1350 			rtnl_lock();
1351 			if (valp == &IPV4_DEVCONF_ALL(net, FORWARDING)) {
1352 				inet_forward_change(net);
1353 			} else if (*valp) {
1354 				struct ipv4_devconf *cnf = ctl->extra1;
1355 				struct in_device *idev =
1356 					container_of(cnf, struct in_device, cnf);
1357 				dev_disable_lro(idev->dev);
1358 			}
1359 			rtnl_unlock();
1360 			rt_cache_flush(net, 0);
1361 		}
1362 	}
1363 
1364 	return ret;
1365 }
1366 
1367 int ipv4_doint_and_flush(ctl_table *ctl, int write,
1368 			 struct file *filp, void __user *buffer,
1369 			 size_t *lenp, loff_t *ppos)
1370 {
1371 	int *valp = ctl->data;
1372 	int val = *valp;
1373 	int ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
1374 	struct net *net = ctl->extra2;
1375 
1376 	if (write && *valp != val)
1377 		rt_cache_flush(net, 0);
1378 
1379 	return ret;
1380 }
1381 
1382 int ipv4_doint_and_flush_strategy(ctl_table *table,
1383 				  void __user *oldval, size_t __user *oldlenp,
1384 				  void __user *newval, size_t newlen)
1385 {
1386 	int ret = devinet_conf_sysctl(table, oldval, oldlenp, newval, newlen);
1387 	struct net *net = table->extra2;
1388 
1389 	if (ret == 1)
1390 		rt_cache_flush(net, 0);
1391 
1392 	return ret;
1393 }
1394 
1395 
1396 #define DEVINET_SYSCTL_ENTRY(attr, name, mval, proc, sysctl) \
1397 	{ \
1398 		.ctl_name	= NET_IPV4_CONF_ ## attr, \
1399 		.procname	= name, \
1400 		.data		= ipv4_devconf.data + \
1401 				  NET_IPV4_CONF_ ## attr - 1, \
1402 		.maxlen		= sizeof(int), \
1403 		.mode		= mval, \
1404 		.proc_handler	= proc, \
1405 		.strategy	= sysctl, \
1406 		.extra1		= &ipv4_devconf, \
1407 	}
1408 
1409 #define DEVINET_SYSCTL_RW_ENTRY(attr, name) \
1410 	DEVINET_SYSCTL_ENTRY(attr, name, 0644, devinet_conf_proc, \
1411 			     devinet_conf_sysctl)
1412 
1413 #define DEVINET_SYSCTL_RO_ENTRY(attr, name) \
1414 	DEVINET_SYSCTL_ENTRY(attr, name, 0444, devinet_conf_proc, \
1415 			     devinet_conf_sysctl)
1416 
1417 #define DEVINET_SYSCTL_COMPLEX_ENTRY(attr, name, proc, sysctl) \
1418 	DEVINET_SYSCTL_ENTRY(attr, name, 0644, proc, sysctl)
1419 
1420 #define DEVINET_SYSCTL_FLUSHING_ENTRY(attr, name) \
1421 	DEVINET_SYSCTL_COMPLEX_ENTRY(attr, name, ipv4_doint_and_flush, \
1422 				     ipv4_doint_and_flush_strategy)
1423 
1424 static struct devinet_sysctl_table {
1425 	struct ctl_table_header *sysctl_header;
1426 	struct ctl_table devinet_vars[__NET_IPV4_CONF_MAX];
1427 	char *dev_name;
1428 } devinet_sysctl = {
1429 	.devinet_vars = {
1430 		DEVINET_SYSCTL_COMPLEX_ENTRY(FORWARDING, "forwarding",
1431 					     devinet_sysctl_forward,
1432 					     devinet_conf_sysctl),
1433 		DEVINET_SYSCTL_RO_ENTRY(MC_FORWARDING, "mc_forwarding"),
1434 
1435 		DEVINET_SYSCTL_RW_ENTRY(ACCEPT_REDIRECTS, "accept_redirects"),
1436 		DEVINET_SYSCTL_RW_ENTRY(SECURE_REDIRECTS, "secure_redirects"),
1437 		DEVINET_SYSCTL_RW_ENTRY(SHARED_MEDIA, "shared_media"),
1438 		DEVINET_SYSCTL_RW_ENTRY(RP_FILTER, "rp_filter"),
1439 		DEVINET_SYSCTL_RW_ENTRY(SEND_REDIRECTS, "send_redirects"),
1440 		DEVINET_SYSCTL_RW_ENTRY(ACCEPT_SOURCE_ROUTE,
1441 					"accept_source_route"),
1442 		DEVINET_SYSCTL_RW_ENTRY(PROXY_ARP, "proxy_arp"),
1443 		DEVINET_SYSCTL_RW_ENTRY(MEDIUM_ID, "medium_id"),
1444 		DEVINET_SYSCTL_RW_ENTRY(BOOTP_RELAY, "bootp_relay"),
1445 		DEVINET_SYSCTL_RW_ENTRY(LOG_MARTIANS, "log_martians"),
1446 		DEVINET_SYSCTL_RW_ENTRY(TAG, "tag"),
1447 		DEVINET_SYSCTL_RW_ENTRY(ARPFILTER, "arp_filter"),
1448 		DEVINET_SYSCTL_RW_ENTRY(ARP_ANNOUNCE, "arp_announce"),
1449 		DEVINET_SYSCTL_RW_ENTRY(ARP_IGNORE, "arp_ignore"),
1450 		DEVINET_SYSCTL_RW_ENTRY(ARP_ACCEPT, "arp_accept"),
1451 		DEVINET_SYSCTL_RW_ENTRY(ARP_NOTIFY, "arp_notify"),
1452 
1453 		DEVINET_SYSCTL_FLUSHING_ENTRY(NOXFRM, "disable_xfrm"),
1454 		DEVINET_SYSCTL_FLUSHING_ENTRY(NOPOLICY, "disable_policy"),
1455 		DEVINET_SYSCTL_FLUSHING_ENTRY(FORCE_IGMP_VERSION,
1456 					      "force_igmp_version"),
1457 		DEVINET_SYSCTL_FLUSHING_ENTRY(PROMOTE_SECONDARIES,
1458 					      "promote_secondaries"),
1459 	},
1460 };
1461 
1462 static int __devinet_sysctl_register(struct net *net, char *dev_name,
1463 		int ctl_name, struct ipv4_devconf *p)
1464 {
1465 	int i;
1466 	struct devinet_sysctl_table *t;
1467 
1468 #define DEVINET_CTL_PATH_DEV	3
1469 
1470 	struct ctl_path devinet_ctl_path[] = {
1471 		{ .procname = "net", .ctl_name = CTL_NET, },
1472 		{ .procname = "ipv4", .ctl_name = NET_IPV4, },
1473 		{ .procname = "conf", .ctl_name = NET_IPV4_CONF, },
1474 		{ /* to be set */ },
1475 		{ },
1476 	};
1477 
1478 	t = kmemdup(&devinet_sysctl, sizeof(*t), GFP_KERNEL);
1479 	if (!t)
1480 		goto out;
1481 
1482 	for (i = 0; i < ARRAY_SIZE(t->devinet_vars) - 1; i++) {
1483 		t->devinet_vars[i].data += (char *)p - (char *)&ipv4_devconf;
1484 		t->devinet_vars[i].extra1 = p;
1485 		t->devinet_vars[i].extra2 = net;
1486 	}
1487 
1488 	/*
1489 	 * Make a copy of dev_name, because '.procname' is regarded as const
1490 	 * by sysctl and we wouldn't want anyone to change it under our feet
1491 	 * (see SIOCSIFNAME).
1492 	 */
1493 	t->dev_name = kstrdup(dev_name, GFP_KERNEL);
1494 	if (!t->dev_name)
1495 		goto free;
1496 
1497 	devinet_ctl_path[DEVINET_CTL_PATH_DEV].procname = t->dev_name;
1498 	devinet_ctl_path[DEVINET_CTL_PATH_DEV].ctl_name = ctl_name;
1499 
1500 	t->sysctl_header = register_net_sysctl_table(net, devinet_ctl_path,
1501 			t->devinet_vars);
1502 	if (!t->sysctl_header)
1503 		goto free_procname;
1504 
1505 	p->sysctl = t;
1506 	return 0;
1507 
1508 free_procname:
1509 	kfree(t->dev_name);
1510 free:
1511 	kfree(t);
1512 out:
1513 	return -ENOBUFS;
1514 }
1515 
1516 static void __devinet_sysctl_unregister(struct ipv4_devconf *cnf)
1517 {
1518 	struct devinet_sysctl_table *t = cnf->sysctl;
1519 
1520 	if (t == NULL)
1521 		return;
1522 
1523 	cnf->sysctl = NULL;
1524 	unregister_sysctl_table(t->sysctl_header);
1525 	kfree(t->dev_name);
1526 	kfree(t);
1527 }
1528 
1529 static void devinet_sysctl_register(struct in_device *idev)
1530 {
1531 	neigh_sysctl_register(idev->dev, idev->arp_parms, NET_IPV4,
1532 			NET_IPV4_NEIGH, "ipv4", NULL, NULL);
1533 	__devinet_sysctl_register(dev_net(idev->dev), idev->dev->name,
1534 			idev->dev->ifindex, &idev->cnf);
1535 }
1536 
1537 static void devinet_sysctl_unregister(struct in_device *idev)
1538 {
1539 	__devinet_sysctl_unregister(&idev->cnf);
1540 	neigh_sysctl_unregister(idev->arp_parms);
1541 }
1542 
1543 static struct ctl_table ctl_forward_entry[] = {
1544 	{
1545 		.ctl_name	= NET_IPV4_FORWARD,
1546 		.procname	= "ip_forward",
1547 		.data		= &ipv4_devconf.data[
1548 					NET_IPV4_CONF_FORWARDING - 1],
1549 		.maxlen		= sizeof(int),
1550 		.mode		= 0644,
1551 		.proc_handler	= devinet_sysctl_forward,
1552 		.strategy	= devinet_conf_sysctl,
1553 		.extra1		= &ipv4_devconf,
1554 		.extra2		= &init_net,
1555 	},
1556 	{ },
1557 };
1558 
1559 static __net_initdata struct ctl_path net_ipv4_path[] = {
1560 	{ .procname = "net", .ctl_name = CTL_NET, },
1561 	{ .procname = "ipv4", .ctl_name = NET_IPV4, },
1562 	{ },
1563 };
1564 #endif
1565 
1566 static __net_init int devinet_init_net(struct net *net)
1567 {
1568 	int err;
1569 	struct ipv4_devconf *all, *dflt;
1570 #ifdef CONFIG_SYSCTL
1571 	struct ctl_table *tbl = ctl_forward_entry;
1572 	struct ctl_table_header *forw_hdr;
1573 #endif
1574 
1575 	err = -ENOMEM;
1576 	all = &ipv4_devconf;
1577 	dflt = &ipv4_devconf_dflt;
1578 
1579 	if (net != &init_net) {
1580 		all = kmemdup(all, sizeof(ipv4_devconf), GFP_KERNEL);
1581 		if (all == NULL)
1582 			goto err_alloc_all;
1583 
1584 		dflt = kmemdup(dflt, sizeof(ipv4_devconf_dflt), GFP_KERNEL);
1585 		if (dflt == NULL)
1586 			goto err_alloc_dflt;
1587 
1588 #ifdef CONFIG_SYSCTL
1589 		tbl = kmemdup(tbl, sizeof(ctl_forward_entry), GFP_KERNEL);
1590 		if (tbl == NULL)
1591 			goto err_alloc_ctl;
1592 
1593 		tbl[0].data = &all->data[NET_IPV4_CONF_FORWARDING - 1];
1594 		tbl[0].extra1 = all;
1595 		tbl[0].extra2 = net;
1596 #endif
1597 	}
1598 
1599 #ifdef CONFIG_SYSCTL
1600 	err = __devinet_sysctl_register(net, "all",
1601 			NET_PROTO_CONF_ALL, all);
1602 	if (err < 0)
1603 		goto err_reg_all;
1604 
1605 	err = __devinet_sysctl_register(net, "default",
1606 			NET_PROTO_CONF_DEFAULT, dflt);
1607 	if (err < 0)
1608 		goto err_reg_dflt;
1609 
1610 	err = -ENOMEM;
1611 	forw_hdr = register_net_sysctl_table(net, net_ipv4_path, tbl);
1612 	if (forw_hdr == NULL)
1613 		goto err_reg_ctl;
1614 	net->ipv4.forw_hdr = forw_hdr;
1615 #endif
1616 
1617 	net->ipv4.devconf_all = all;
1618 	net->ipv4.devconf_dflt = dflt;
1619 	return 0;
1620 
1621 #ifdef CONFIG_SYSCTL
1622 err_reg_ctl:
1623 	__devinet_sysctl_unregister(dflt);
1624 err_reg_dflt:
1625 	__devinet_sysctl_unregister(all);
1626 err_reg_all:
1627 	if (tbl != ctl_forward_entry)
1628 		kfree(tbl);
1629 err_alloc_ctl:
1630 #endif
1631 	if (dflt != &ipv4_devconf_dflt)
1632 		kfree(dflt);
1633 err_alloc_dflt:
1634 	if (all != &ipv4_devconf)
1635 		kfree(all);
1636 err_alloc_all:
1637 	return err;
1638 }
1639 
1640 static __net_exit void devinet_exit_net(struct net *net)
1641 {
1642 #ifdef CONFIG_SYSCTL
1643 	struct ctl_table *tbl;
1644 
1645 	tbl = net->ipv4.forw_hdr->ctl_table_arg;
1646 	unregister_net_sysctl_table(net->ipv4.forw_hdr);
1647 	__devinet_sysctl_unregister(net->ipv4.devconf_dflt);
1648 	__devinet_sysctl_unregister(net->ipv4.devconf_all);
1649 	kfree(tbl);
1650 #endif
1651 	kfree(net->ipv4.devconf_dflt);
1652 	kfree(net->ipv4.devconf_all);
1653 }
1654 
1655 static __net_initdata struct pernet_operations devinet_ops = {
1656 	.init = devinet_init_net,
1657 	.exit = devinet_exit_net,
1658 };
1659 
1660 void __init devinet_init(void)
1661 {
1662 	register_pernet_subsys(&devinet_ops);
1663 
1664 	register_gifconf(PF_INET, inet_gifconf);
1665 	register_netdevice_notifier(&ip_netdev_notifier);
1666 
1667 	rtnl_register(PF_INET, RTM_NEWADDR, inet_rtm_newaddr, NULL);
1668 	rtnl_register(PF_INET, RTM_DELADDR, inet_rtm_deladdr, NULL);
1669 	rtnl_register(PF_INET, RTM_GETADDR, NULL, inet_dump_ifaddr);
1670 }
1671 
1672 EXPORT_SYMBOL(in_dev_finish_destroy);
1673 EXPORT_SYMBOL(inet_select_addr);
1674 EXPORT_SYMBOL(inetdev_by_index);
1675 EXPORT_SYMBOL(register_inetaddr_notifier);
1676 EXPORT_SYMBOL(unregister_inetaddr_notifier);
1677