xref: /openbmc/linux/net/ipv4/ip_sockglue.c (revision 5f32c314)
1 /*
2  * INET		An implementation of the TCP/IP protocol suite for the LINUX
3  *		operating system.  INET is implemented using the  BSD Socket
4  *		interface as the means of communication with the user level.
5  *
6  *		The IP to API glue.
7  *
8  * Authors:	see ip.c
9  *
10  * Fixes:
11  *		Many		:	Split from ip.c , see ip.c for history.
12  *		Martin Mares	:	TOS setting fixed.
13  *		Alan Cox	:	Fixed a couple of oopses in Martin's
14  *					TOS tweaks.
15  *		Mike McLagan	:	Routing by source
16  */
17 
18 #include <linux/module.h>
19 #include <linux/types.h>
20 #include <linux/mm.h>
21 #include <linux/skbuff.h>
22 #include <linux/ip.h>
23 #include <linux/icmp.h>
24 #include <linux/inetdevice.h>
25 #include <linux/netdevice.h>
26 #include <linux/slab.h>
27 #include <net/sock.h>
28 #include <net/ip.h>
29 #include <net/icmp.h>
30 #include <net/tcp_states.h>
31 #include <linux/udp.h>
32 #include <linux/igmp.h>
33 #include <linux/netfilter.h>
34 #include <linux/route.h>
35 #include <linux/mroute.h>
36 #include <net/inet_ecn.h>
37 #include <net/route.h>
38 #include <net/xfrm.h>
39 #include <net/compat.h>
40 #if IS_ENABLED(CONFIG_IPV6)
41 #include <net/transp_v6.h>
42 #endif
43 #include <net/ip_fib.h>
44 
45 #include <linux/errqueue.h>
46 #include <asm/uaccess.h>
47 
48 #define IP_CMSG_PKTINFO		1
49 #define IP_CMSG_TTL		2
50 #define IP_CMSG_TOS		4
51 #define IP_CMSG_RECVOPTS	8
52 #define IP_CMSG_RETOPTS		16
53 #define IP_CMSG_PASSSEC		32
54 #define IP_CMSG_ORIGDSTADDR     64
55 
56 /*
57  *	SOL_IP control messages.
58  */
59 
60 static void ip_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
61 {
62 	struct in_pktinfo info = *PKTINFO_SKB_CB(skb);
63 
64 	info.ipi_addr.s_addr = ip_hdr(skb)->daddr;
65 
66 	put_cmsg(msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
67 }
68 
69 static void ip_cmsg_recv_ttl(struct msghdr *msg, struct sk_buff *skb)
70 {
71 	int ttl = ip_hdr(skb)->ttl;
72 	put_cmsg(msg, SOL_IP, IP_TTL, sizeof(int), &ttl);
73 }
74 
75 static void ip_cmsg_recv_tos(struct msghdr *msg, struct sk_buff *skb)
76 {
77 	put_cmsg(msg, SOL_IP, IP_TOS, 1, &ip_hdr(skb)->tos);
78 }
79 
80 static void ip_cmsg_recv_opts(struct msghdr *msg, struct sk_buff *skb)
81 {
82 	if (IPCB(skb)->opt.optlen == 0)
83 		return;
84 
85 	put_cmsg(msg, SOL_IP, IP_RECVOPTS, IPCB(skb)->opt.optlen,
86 		 ip_hdr(skb) + 1);
87 }
88 
89 
90 static void ip_cmsg_recv_retopts(struct msghdr *msg, struct sk_buff *skb)
91 {
92 	unsigned char optbuf[sizeof(struct ip_options) + 40];
93 	struct ip_options *opt = (struct ip_options *)optbuf;
94 
95 	if (IPCB(skb)->opt.optlen == 0)
96 		return;
97 
98 	if (ip_options_echo(opt, skb)) {
99 		msg->msg_flags |= MSG_CTRUNC;
100 		return;
101 	}
102 	ip_options_undo(opt);
103 
104 	put_cmsg(msg, SOL_IP, IP_RETOPTS, opt->optlen, opt->__data);
105 }
106 
107 static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
108 {
109 	char *secdata;
110 	u32 seclen, secid;
111 	int err;
112 
113 	err = security_socket_getpeersec_dgram(NULL, skb, &secid);
114 	if (err)
115 		return;
116 
117 	err = security_secid_to_secctx(secid, &secdata, &seclen);
118 	if (err)
119 		return;
120 
121 	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
122 	security_release_secctx(secdata, seclen);
123 }
124 
125 static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
126 {
127 	struct sockaddr_in sin;
128 	const struct iphdr *iph = ip_hdr(skb);
129 	__be16 *ports = (__be16 *)skb_transport_header(skb);
130 
131 	if (skb_transport_offset(skb) + 4 > skb->len)
132 		return;
133 
134 	/* All current transport protocols have the port numbers in the
135 	 * first four bytes of the transport header and this function is
136 	 * written with this assumption in mind.
137 	 */
138 
139 	sin.sin_family = AF_INET;
140 	sin.sin_addr.s_addr = iph->daddr;
141 	sin.sin_port = ports[1];
142 	memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
143 
144 	put_cmsg(msg, SOL_IP, IP_ORIGDSTADDR, sizeof(sin), &sin);
145 }
146 
147 void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
148 {
149 	struct inet_sock *inet = inet_sk(skb->sk);
150 	unsigned int flags = inet->cmsg_flags;
151 
152 	/* Ordered by supposed usage frequency */
153 	if (flags & 1)
154 		ip_cmsg_recv_pktinfo(msg, skb);
155 	if ((flags >>= 1) == 0)
156 		return;
157 
158 	if (flags & 1)
159 		ip_cmsg_recv_ttl(msg, skb);
160 	if ((flags >>= 1) == 0)
161 		return;
162 
163 	if (flags & 1)
164 		ip_cmsg_recv_tos(msg, skb);
165 	if ((flags >>= 1) == 0)
166 		return;
167 
168 	if (flags & 1)
169 		ip_cmsg_recv_opts(msg, skb);
170 	if ((flags >>= 1) == 0)
171 		return;
172 
173 	if (flags & 1)
174 		ip_cmsg_recv_retopts(msg, skb);
175 	if ((flags >>= 1) == 0)
176 		return;
177 
178 	if (flags & 1)
179 		ip_cmsg_recv_security(msg, skb);
180 
181 	if ((flags >>= 1) == 0)
182 		return;
183 	if (flags & 1)
184 		ip_cmsg_recv_dstaddr(msg, skb);
185 
186 }
187 EXPORT_SYMBOL(ip_cmsg_recv);
188 
189 int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc)
190 {
191 	int err, val;
192 	struct cmsghdr *cmsg;
193 
194 	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
195 		if (!CMSG_OK(msg, cmsg))
196 			return -EINVAL;
197 		if (cmsg->cmsg_level != SOL_IP)
198 			continue;
199 		switch (cmsg->cmsg_type) {
200 		case IP_RETOPTS:
201 			err = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
202 			err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg),
203 					     err < 40 ? err : 40);
204 			if (err)
205 				return err;
206 			break;
207 		case IP_PKTINFO:
208 		{
209 			struct in_pktinfo *info;
210 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
211 				return -EINVAL;
212 			info = (struct in_pktinfo *)CMSG_DATA(cmsg);
213 			ipc->oif = info->ipi_ifindex;
214 			ipc->addr = info->ipi_spec_dst.s_addr;
215 			break;
216 		}
217 		case IP_TTL:
218 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
219 				return -EINVAL;
220 			val = *(int *)CMSG_DATA(cmsg);
221 			if (val < 1 || val > 255)
222 				return -EINVAL;
223 			ipc->ttl = val;
224 			break;
225 		case IP_TOS:
226 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
227 				return -EINVAL;
228 			val = *(int *)CMSG_DATA(cmsg);
229 			if (val < 0 || val > 255)
230 				return -EINVAL;
231 			ipc->tos = val;
232 			ipc->priority = rt_tos2priority(ipc->tos);
233 			break;
234 
235 		default:
236 			return -EINVAL;
237 		}
238 	}
239 	return 0;
240 }
241 
242 
243 /* Special input handler for packets caught by router alert option.
244    They are selected only by protocol field, and then processed likely
245    local ones; but only if someone wants them! Otherwise, router
246    not running rsvpd will kill RSVP.
247 
248    It is user level problem, what it will make with them.
249    I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
250    but receiver should be enough clever f.e. to forward mtrace requests,
251    sent to multicast group to reach destination designated router.
252  */
253 struct ip_ra_chain __rcu *ip_ra_chain;
254 static DEFINE_SPINLOCK(ip_ra_lock);
255 
256 
257 static void ip_ra_destroy_rcu(struct rcu_head *head)
258 {
259 	struct ip_ra_chain *ra = container_of(head, struct ip_ra_chain, rcu);
260 
261 	sock_put(ra->saved_sk);
262 	kfree(ra);
263 }
264 
265 int ip_ra_control(struct sock *sk, unsigned char on,
266 		  void (*destructor)(struct sock *))
267 {
268 	struct ip_ra_chain *ra, *new_ra;
269 	struct ip_ra_chain __rcu **rap;
270 
271 	if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num == IPPROTO_RAW)
272 		return -EINVAL;
273 
274 	new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
275 
276 	spin_lock_bh(&ip_ra_lock);
277 	for (rap = &ip_ra_chain;
278 	     (ra = rcu_dereference_protected(*rap,
279 			lockdep_is_held(&ip_ra_lock))) != NULL;
280 	     rap = &ra->next) {
281 		if (ra->sk == sk) {
282 			if (on) {
283 				spin_unlock_bh(&ip_ra_lock);
284 				kfree(new_ra);
285 				return -EADDRINUSE;
286 			}
287 			/* dont let ip_call_ra_chain() use sk again */
288 			ra->sk = NULL;
289 			rcu_assign_pointer(*rap, ra->next);
290 			spin_unlock_bh(&ip_ra_lock);
291 
292 			if (ra->destructor)
293 				ra->destructor(sk);
294 			/*
295 			 * Delay sock_put(sk) and kfree(ra) after one rcu grace
296 			 * period. This guarantee ip_call_ra_chain() dont need
297 			 * to mess with socket refcounts.
298 			 */
299 			ra->saved_sk = sk;
300 			call_rcu(&ra->rcu, ip_ra_destroy_rcu);
301 			return 0;
302 		}
303 	}
304 	if (new_ra == NULL) {
305 		spin_unlock_bh(&ip_ra_lock);
306 		return -ENOBUFS;
307 	}
308 	new_ra->sk = sk;
309 	new_ra->destructor = destructor;
310 
311 	new_ra->next = ra;
312 	rcu_assign_pointer(*rap, new_ra);
313 	sock_hold(sk);
314 	spin_unlock_bh(&ip_ra_lock);
315 
316 	return 0;
317 }
318 
319 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
320 		   __be16 port, u32 info, u8 *payload)
321 {
322 	struct sock_exterr_skb *serr;
323 
324 	skb = skb_clone(skb, GFP_ATOMIC);
325 	if (!skb)
326 		return;
327 
328 	serr = SKB_EXT_ERR(skb);
329 	serr->ee.ee_errno = err;
330 	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
331 	serr->ee.ee_type = icmp_hdr(skb)->type;
332 	serr->ee.ee_code = icmp_hdr(skb)->code;
333 	serr->ee.ee_pad = 0;
334 	serr->ee.ee_info = info;
335 	serr->ee.ee_data = 0;
336 	serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -
337 				   skb_network_header(skb);
338 	serr->port = port;
339 
340 	if (skb_pull(skb, payload - skb->data) != NULL) {
341 		skb_reset_transport_header(skb);
342 		if (sock_queue_err_skb(sk, skb) == 0)
343 			return;
344 	}
345 	kfree_skb(skb);
346 }
347 
348 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
349 {
350 	struct inet_sock *inet = inet_sk(sk);
351 	struct sock_exterr_skb *serr;
352 	struct iphdr *iph;
353 	struct sk_buff *skb;
354 
355 	if (!inet->recverr)
356 		return;
357 
358 	skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
359 	if (!skb)
360 		return;
361 
362 	skb_put(skb, sizeof(struct iphdr));
363 	skb_reset_network_header(skb);
364 	iph = ip_hdr(skb);
365 	iph->daddr = daddr;
366 
367 	serr = SKB_EXT_ERR(skb);
368 	serr->ee.ee_errno = err;
369 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
370 	serr->ee.ee_type = 0;
371 	serr->ee.ee_code = 0;
372 	serr->ee.ee_pad = 0;
373 	serr->ee.ee_info = info;
374 	serr->ee.ee_data = 0;
375 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
376 	serr->port = port;
377 
378 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
379 	skb_reset_transport_header(skb);
380 
381 	if (sock_queue_err_skb(sk, skb))
382 		kfree_skb(skb);
383 }
384 
385 /*
386  *	Handle MSG_ERRQUEUE
387  */
388 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
389 {
390 	struct sock_exterr_skb *serr;
391 	struct sk_buff *skb, *skb2;
392 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
393 	struct {
394 		struct sock_extended_err ee;
395 		struct sockaddr_in	 offender;
396 	} errhdr;
397 	int err;
398 	int copied;
399 
400 	err = -EAGAIN;
401 	skb = skb_dequeue(&sk->sk_error_queue);
402 	if (skb == NULL)
403 		goto out;
404 
405 	copied = skb->len;
406 	if (copied > len) {
407 		msg->msg_flags |= MSG_TRUNC;
408 		copied = len;
409 	}
410 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
411 	if (err)
412 		goto out_free_skb;
413 
414 	sock_recv_timestamp(msg, sk, skb);
415 
416 	serr = SKB_EXT_ERR(skb);
417 
418 	if (sin) {
419 		sin->sin_family = AF_INET;
420 		sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
421 						   serr->addr_offset);
422 		sin->sin_port = serr->port;
423 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
424 		*addr_len = sizeof(*sin);
425 	}
426 
427 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
428 	sin = &errhdr.offender;
429 	sin->sin_family = AF_UNSPEC;
430 	if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP) {
431 		struct inet_sock *inet = inet_sk(sk);
432 
433 		sin->sin_family = AF_INET;
434 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
435 		sin->sin_port = 0;
436 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
437 		if (inet->cmsg_flags)
438 			ip_cmsg_recv(msg, skb);
439 	}
440 
441 	put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
442 
443 	/* Now we could try to dump offended packet options */
444 
445 	msg->msg_flags |= MSG_ERRQUEUE;
446 	err = copied;
447 
448 	/* Reset and regenerate socket error */
449 	spin_lock_bh(&sk->sk_error_queue.lock);
450 	sk->sk_err = 0;
451 	skb2 = skb_peek(&sk->sk_error_queue);
452 	if (skb2 != NULL) {
453 		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
454 		spin_unlock_bh(&sk->sk_error_queue.lock);
455 		sk->sk_error_report(sk);
456 	} else
457 		spin_unlock_bh(&sk->sk_error_queue.lock);
458 
459 out_free_skb:
460 	kfree_skb(skb);
461 out:
462 	return err;
463 }
464 
465 
466 /*
467  *	Socket option code for IP. This is the end of the line after any
468  *	TCP,UDP etc options on an IP socket.
469  */
470 
471 static int do_ip_setsockopt(struct sock *sk, int level,
472 			    int optname, char __user *optval, unsigned int optlen)
473 {
474 	struct inet_sock *inet = inet_sk(sk);
475 	int val = 0, err;
476 
477 	switch (optname) {
478 	case IP_PKTINFO:
479 	case IP_RECVTTL:
480 	case IP_RECVOPTS:
481 	case IP_RECVTOS:
482 	case IP_RETOPTS:
483 	case IP_TOS:
484 	case IP_TTL:
485 	case IP_HDRINCL:
486 	case IP_MTU_DISCOVER:
487 	case IP_RECVERR:
488 	case IP_ROUTER_ALERT:
489 	case IP_FREEBIND:
490 	case IP_PASSSEC:
491 	case IP_TRANSPARENT:
492 	case IP_MINTTL:
493 	case IP_NODEFRAG:
494 	case IP_UNICAST_IF:
495 	case IP_MULTICAST_TTL:
496 	case IP_MULTICAST_ALL:
497 	case IP_MULTICAST_LOOP:
498 	case IP_RECVORIGDSTADDR:
499 		if (optlen >= sizeof(int)) {
500 			if (get_user(val, (int __user *) optval))
501 				return -EFAULT;
502 		} else if (optlen >= sizeof(char)) {
503 			unsigned char ucval;
504 
505 			if (get_user(ucval, (unsigned char __user *) optval))
506 				return -EFAULT;
507 			val = (int) ucval;
508 		}
509 	}
510 
511 	/* If optlen==0, it is equivalent to val == 0 */
512 
513 	if (ip_mroute_opt(optname))
514 		return ip_mroute_setsockopt(sk, optname, optval, optlen);
515 
516 	err = 0;
517 	lock_sock(sk);
518 
519 	switch (optname) {
520 	case IP_OPTIONS:
521 	{
522 		struct ip_options_rcu *old, *opt = NULL;
523 
524 		if (optlen > 40)
525 			goto e_inval;
526 		err = ip_options_get_from_user(sock_net(sk), &opt,
527 					       optval, optlen);
528 		if (err)
529 			break;
530 		old = rcu_dereference_protected(inet->inet_opt,
531 						sock_owned_by_user(sk));
532 		if (inet->is_icsk) {
533 			struct inet_connection_sock *icsk = inet_csk(sk);
534 #if IS_ENABLED(CONFIG_IPV6)
535 			if (sk->sk_family == PF_INET ||
536 			    (!((1 << sk->sk_state) &
537 			       (TCPF_LISTEN | TCPF_CLOSE)) &&
538 			     inet->inet_daddr != LOOPBACK4_IPV6)) {
539 #endif
540 				if (old)
541 					icsk->icsk_ext_hdr_len -= old->opt.optlen;
542 				if (opt)
543 					icsk->icsk_ext_hdr_len += opt->opt.optlen;
544 				icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
545 #if IS_ENABLED(CONFIG_IPV6)
546 			}
547 #endif
548 		}
549 		rcu_assign_pointer(inet->inet_opt, opt);
550 		if (old)
551 			kfree_rcu(old, rcu);
552 		break;
553 	}
554 	case IP_PKTINFO:
555 		if (val)
556 			inet->cmsg_flags |= IP_CMSG_PKTINFO;
557 		else
558 			inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
559 		break;
560 	case IP_RECVTTL:
561 		if (val)
562 			inet->cmsg_flags |=  IP_CMSG_TTL;
563 		else
564 			inet->cmsg_flags &= ~IP_CMSG_TTL;
565 		break;
566 	case IP_RECVTOS:
567 		if (val)
568 			inet->cmsg_flags |=  IP_CMSG_TOS;
569 		else
570 			inet->cmsg_flags &= ~IP_CMSG_TOS;
571 		break;
572 	case IP_RECVOPTS:
573 		if (val)
574 			inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
575 		else
576 			inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
577 		break;
578 	case IP_RETOPTS:
579 		if (val)
580 			inet->cmsg_flags |= IP_CMSG_RETOPTS;
581 		else
582 			inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
583 		break;
584 	case IP_PASSSEC:
585 		if (val)
586 			inet->cmsg_flags |= IP_CMSG_PASSSEC;
587 		else
588 			inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
589 		break;
590 	case IP_RECVORIGDSTADDR:
591 		if (val)
592 			inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
593 		else
594 			inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
595 		break;
596 	case IP_TOS:	/* This sets both TOS and Precedence */
597 		if (sk->sk_type == SOCK_STREAM) {
598 			val &= ~INET_ECN_MASK;
599 			val |= inet->tos & INET_ECN_MASK;
600 		}
601 		if (inet->tos != val) {
602 			inet->tos = val;
603 			sk->sk_priority = rt_tos2priority(val);
604 			sk_dst_reset(sk);
605 		}
606 		break;
607 	case IP_TTL:
608 		if (optlen < 1)
609 			goto e_inval;
610 		if (val != -1 && (val < 1 || val > 255))
611 			goto e_inval;
612 		inet->uc_ttl = val;
613 		break;
614 	case IP_HDRINCL:
615 		if (sk->sk_type != SOCK_RAW) {
616 			err = -ENOPROTOOPT;
617 			break;
618 		}
619 		inet->hdrincl = val ? 1 : 0;
620 		break;
621 	case IP_NODEFRAG:
622 		if (sk->sk_type != SOCK_RAW) {
623 			err = -ENOPROTOOPT;
624 			break;
625 		}
626 		inet->nodefrag = val ? 1 : 0;
627 		break;
628 	case IP_MTU_DISCOVER:
629 		if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_INTERFACE)
630 			goto e_inval;
631 		inet->pmtudisc = val;
632 		break;
633 	case IP_RECVERR:
634 		inet->recverr = !!val;
635 		if (!val)
636 			skb_queue_purge(&sk->sk_error_queue);
637 		break;
638 	case IP_MULTICAST_TTL:
639 		if (sk->sk_type == SOCK_STREAM)
640 			goto e_inval;
641 		if (optlen < 1)
642 			goto e_inval;
643 		if (val == -1)
644 			val = 1;
645 		if (val < 0 || val > 255)
646 			goto e_inval;
647 		inet->mc_ttl = val;
648 		break;
649 	case IP_MULTICAST_LOOP:
650 		if (optlen < 1)
651 			goto e_inval;
652 		inet->mc_loop = !!val;
653 		break;
654 	case IP_UNICAST_IF:
655 	{
656 		struct net_device *dev = NULL;
657 		int ifindex;
658 
659 		if (optlen != sizeof(int))
660 			goto e_inval;
661 
662 		ifindex = (__force int)ntohl((__force __be32)val);
663 		if (ifindex == 0) {
664 			inet->uc_index = 0;
665 			err = 0;
666 			break;
667 		}
668 
669 		dev = dev_get_by_index(sock_net(sk), ifindex);
670 		err = -EADDRNOTAVAIL;
671 		if (!dev)
672 			break;
673 		dev_put(dev);
674 
675 		err = -EINVAL;
676 		if (sk->sk_bound_dev_if)
677 			break;
678 
679 		inet->uc_index = ifindex;
680 		err = 0;
681 		break;
682 	}
683 	case IP_MULTICAST_IF:
684 	{
685 		struct ip_mreqn mreq;
686 		struct net_device *dev = NULL;
687 
688 		if (sk->sk_type == SOCK_STREAM)
689 			goto e_inval;
690 		/*
691 		 *	Check the arguments are allowable
692 		 */
693 
694 		if (optlen < sizeof(struct in_addr))
695 			goto e_inval;
696 
697 		err = -EFAULT;
698 		if (optlen >= sizeof(struct ip_mreqn)) {
699 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
700 				break;
701 		} else {
702 			memset(&mreq, 0, sizeof(mreq));
703 			if (optlen >= sizeof(struct ip_mreq)) {
704 				if (copy_from_user(&mreq, optval,
705 						   sizeof(struct ip_mreq)))
706 					break;
707 			} else if (optlen >= sizeof(struct in_addr)) {
708 				if (copy_from_user(&mreq.imr_address, optval,
709 						   sizeof(struct in_addr)))
710 					break;
711 			}
712 		}
713 
714 		if (!mreq.imr_ifindex) {
715 			if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
716 				inet->mc_index = 0;
717 				inet->mc_addr  = 0;
718 				err = 0;
719 				break;
720 			}
721 			dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
722 			if (dev)
723 				mreq.imr_ifindex = dev->ifindex;
724 		} else
725 			dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
726 
727 
728 		err = -EADDRNOTAVAIL;
729 		if (!dev)
730 			break;
731 		dev_put(dev);
732 
733 		err = -EINVAL;
734 		if (sk->sk_bound_dev_if &&
735 		    mreq.imr_ifindex != sk->sk_bound_dev_if)
736 			break;
737 
738 		inet->mc_index = mreq.imr_ifindex;
739 		inet->mc_addr  = mreq.imr_address.s_addr;
740 		err = 0;
741 		break;
742 	}
743 
744 	case IP_ADD_MEMBERSHIP:
745 	case IP_DROP_MEMBERSHIP:
746 	{
747 		struct ip_mreqn mreq;
748 
749 		err = -EPROTO;
750 		if (inet_sk(sk)->is_icsk)
751 			break;
752 
753 		if (optlen < sizeof(struct ip_mreq))
754 			goto e_inval;
755 		err = -EFAULT;
756 		if (optlen >= sizeof(struct ip_mreqn)) {
757 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
758 				break;
759 		} else {
760 			memset(&mreq, 0, sizeof(mreq));
761 			if (copy_from_user(&mreq, optval, sizeof(struct ip_mreq)))
762 				break;
763 		}
764 
765 		if (optname == IP_ADD_MEMBERSHIP)
766 			err = ip_mc_join_group(sk, &mreq);
767 		else
768 			err = ip_mc_leave_group(sk, &mreq);
769 		break;
770 	}
771 	case IP_MSFILTER:
772 	{
773 		struct ip_msfilter *msf;
774 
775 		if (optlen < IP_MSFILTER_SIZE(0))
776 			goto e_inval;
777 		if (optlen > sysctl_optmem_max) {
778 			err = -ENOBUFS;
779 			break;
780 		}
781 		msf = kmalloc(optlen, GFP_KERNEL);
782 		if (!msf) {
783 			err = -ENOBUFS;
784 			break;
785 		}
786 		err = -EFAULT;
787 		if (copy_from_user(msf, optval, optlen)) {
788 			kfree(msf);
789 			break;
790 		}
791 		/* numsrc >= (1G-4) overflow in 32 bits */
792 		if (msf->imsf_numsrc >= 0x3ffffffcU ||
793 		    msf->imsf_numsrc > sysctl_igmp_max_msf) {
794 			kfree(msf);
795 			err = -ENOBUFS;
796 			break;
797 		}
798 		if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
799 			kfree(msf);
800 			err = -EINVAL;
801 			break;
802 		}
803 		err = ip_mc_msfilter(sk, msf, 0);
804 		kfree(msf);
805 		break;
806 	}
807 	case IP_BLOCK_SOURCE:
808 	case IP_UNBLOCK_SOURCE:
809 	case IP_ADD_SOURCE_MEMBERSHIP:
810 	case IP_DROP_SOURCE_MEMBERSHIP:
811 	{
812 		struct ip_mreq_source mreqs;
813 		int omode, add;
814 
815 		if (optlen != sizeof(struct ip_mreq_source))
816 			goto e_inval;
817 		if (copy_from_user(&mreqs, optval, sizeof(mreqs))) {
818 			err = -EFAULT;
819 			break;
820 		}
821 		if (optname == IP_BLOCK_SOURCE) {
822 			omode = MCAST_EXCLUDE;
823 			add = 1;
824 		} else if (optname == IP_UNBLOCK_SOURCE) {
825 			omode = MCAST_EXCLUDE;
826 			add = 0;
827 		} else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
828 			struct ip_mreqn mreq;
829 
830 			mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
831 			mreq.imr_address.s_addr = mreqs.imr_interface;
832 			mreq.imr_ifindex = 0;
833 			err = ip_mc_join_group(sk, &mreq);
834 			if (err && err != -EADDRINUSE)
835 				break;
836 			omode = MCAST_INCLUDE;
837 			add = 1;
838 		} else /* IP_DROP_SOURCE_MEMBERSHIP */ {
839 			omode = MCAST_INCLUDE;
840 			add = 0;
841 		}
842 		err = ip_mc_source(add, omode, sk, &mreqs, 0);
843 		break;
844 	}
845 	case MCAST_JOIN_GROUP:
846 	case MCAST_LEAVE_GROUP:
847 	{
848 		struct group_req greq;
849 		struct sockaddr_in *psin;
850 		struct ip_mreqn mreq;
851 
852 		if (optlen < sizeof(struct group_req))
853 			goto e_inval;
854 		err = -EFAULT;
855 		if (copy_from_user(&greq, optval, sizeof(greq)))
856 			break;
857 		psin = (struct sockaddr_in *)&greq.gr_group;
858 		if (psin->sin_family != AF_INET)
859 			goto e_inval;
860 		memset(&mreq, 0, sizeof(mreq));
861 		mreq.imr_multiaddr = psin->sin_addr;
862 		mreq.imr_ifindex = greq.gr_interface;
863 
864 		if (optname == MCAST_JOIN_GROUP)
865 			err = ip_mc_join_group(sk, &mreq);
866 		else
867 			err = ip_mc_leave_group(sk, &mreq);
868 		break;
869 	}
870 	case MCAST_JOIN_SOURCE_GROUP:
871 	case MCAST_LEAVE_SOURCE_GROUP:
872 	case MCAST_BLOCK_SOURCE:
873 	case MCAST_UNBLOCK_SOURCE:
874 	{
875 		struct group_source_req greqs;
876 		struct ip_mreq_source mreqs;
877 		struct sockaddr_in *psin;
878 		int omode, add;
879 
880 		if (optlen != sizeof(struct group_source_req))
881 			goto e_inval;
882 		if (copy_from_user(&greqs, optval, sizeof(greqs))) {
883 			err = -EFAULT;
884 			break;
885 		}
886 		if (greqs.gsr_group.ss_family != AF_INET ||
887 		    greqs.gsr_source.ss_family != AF_INET) {
888 			err = -EADDRNOTAVAIL;
889 			break;
890 		}
891 		psin = (struct sockaddr_in *)&greqs.gsr_group;
892 		mreqs.imr_multiaddr = psin->sin_addr.s_addr;
893 		psin = (struct sockaddr_in *)&greqs.gsr_source;
894 		mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
895 		mreqs.imr_interface = 0; /* use index for mc_source */
896 
897 		if (optname == MCAST_BLOCK_SOURCE) {
898 			omode = MCAST_EXCLUDE;
899 			add = 1;
900 		} else if (optname == MCAST_UNBLOCK_SOURCE) {
901 			omode = MCAST_EXCLUDE;
902 			add = 0;
903 		} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
904 			struct ip_mreqn mreq;
905 
906 			psin = (struct sockaddr_in *)&greqs.gsr_group;
907 			mreq.imr_multiaddr = psin->sin_addr;
908 			mreq.imr_address.s_addr = 0;
909 			mreq.imr_ifindex = greqs.gsr_interface;
910 			err = ip_mc_join_group(sk, &mreq);
911 			if (err && err != -EADDRINUSE)
912 				break;
913 			greqs.gsr_interface = mreq.imr_ifindex;
914 			omode = MCAST_INCLUDE;
915 			add = 1;
916 		} else /* MCAST_LEAVE_SOURCE_GROUP */ {
917 			omode = MCAST_INCLUDE;
918 			add = 0;
919 		}
920 		err = ip_mc_source(add, omode, sk, &mreqs,
921 				   greqs.gsr_interface);
922 		break;
923 	}
924 	case MCAST_MSFILTER:
925 	{
926 		struct sockaddr_in *psin;
927 		struct ip_msfilter *msf = NULL;
928 		struct group_filter *gsf = NULL;
929 		int msize, i, ifindex;
930 
931 		if (optlen < GROUP_FILTER_SIZE(0))
932 			goto e_inval;
933 		if (optlen > sysctl_optmem_max) {
934 			err = -ENOBUFS;
935 			break;
936 		}
937 		gsf = kmalloc(optlen, GFP_KERNEL);
938 		if (!gsf) {
939 			err = -ENOBUFS;
940 			break;
941 		}
942 		err = -EFAULT;
943 		if (copy_from_user(gsf, optval, optlen))
944 			goto mc_msf_out;
945 
946 		/* numsrc >= (4G-140)/128 overflow in 32 bits */
947 		if (gsf->gf_numsrc >= 0x1ffffff ||
948 		    gsf->gf_numsrc > sysctl_igmp_max_msf) {
949 			err = -ENOBUFS;
950 			goto mc_msf_out;
951 		}
952 		if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
953 			err = -EINVAL;
954 			goto mc_msf_out;
955 		}
956 		msize = IP_MSFILTER_SIZE(gsf->gf_numsrc);
957 		msf = kmalloc(msize, GFP_KERNEL);
958 		if (!msf) {
959 			err = -ENOBUFS;
960 			goto mc_msf_out;
961 		}
962 		ifindex = gsf->gf_interface;
963 		psin = (struct sockaddr_in *)&gsf->gf_group;
964 		if (psin->sin_family != AF_INET) {
965 			err = -EADDRNOTAVAIL;
966 			goto mc_msf_out;
967 		}
968 		msf->imsf_multiaddr = psin->sin_addr.s_addr;
969 		msf->imsf_interface = 0;
970 		msf->imsf_fmode = gsf->gf_fmode;
971 		msf->imsf_numsrc = gsf->gf_numsrc;
972 		err = -EADDRNOTAVAIL;
973 		for (i = 0; i < gsf->gf_numsrc; ++i) {
974 			psin = (struct sockaddr_in *)&gsf->gf_slist[i];
975 
976 			if (psin->sin_family != AF_INET)
977 				goto mc_msf_out;
978 			msf->imsf_slist[i] = psin->sin_addr.s_addr;
979 		}
980 		kfree(gsf);
981 		gsf = NULL;
982 
983 		err = ip_mc_msfilter(sk, msf, ifindex);
984 mc_msf_out:
985 		kfree(msf);
986 		kfree(gsf);
987 		break;
988 	}
989 	case IP_MULTICAST_ALL:
990 		if (optlen < 1)
991 			goto e_inval;
992 		if (val != 0 && val != 1)
993 			goto e_inval;
994 		inet->mc_all = val;
995 		break;
996 	case IP_ROUTER_ALERT:
997 		err = ip_ra_control(sk, val ? 1 : 0, NULL);
998 		break;
999 
1000 	case IP_FREEBIND:
1001 		if (optlen < 1)
1002 			goto e_inval;
1003 		inet->freebind = !!val;
1004 		break;
1005 
1006 	case IP_IPSEC_POLICY:
1007 	case IP_XFRM_POLICY:
1008 		err = -EPERM;
1009 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1010 			break;
1011 		err = xfrm_user_policy(sk, optname, optval, optlen);
1012 		break;
1013 
1014 	case IP_TRANSPARENT:
1015 		if (!!val && !ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1016 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1017 			err = -EPERM;
1018 			break;
1019 		}
1020 		if (optlen < 1)
1021 			goto e_inval;
1022 		inet->transparent = !!val;
1023 		break;
1024 
1025 	case IP_MINTTL:
1026 		if (optlen < 1)
1027 			goto e_inval;
1028 		if (val < 0 || val > 255)
1029 			goto e_inval;
1030 		inet->min_ttl = val;
1031 		break;
1032 
1033 	default:
1034 		err = -ENOPROTOOPT;
1035 		break;
1036 	}
1037 	release_sock(sk);
1038 	return err;
1039 
1040 e_inval:
1041 	release_sock(sk);
1042 	return -EINVAL;
1043 }
1044 
1045 /**
1046  * ipv4_pktinfo_prepare - transfert some info from rtable to skb
1047  * @sk: socket
1048  * @skb: buffer
1049  *
1050  * To support IP_CMSG_PKTINFO option, we store rt_iif and specific
1051  * destination in skb->cb[] before dst drop.
1052  * This way, receiver doesn't make cache line misses to read rtable.
1053  */
1054 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
1055 {
1056 	struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
1057 	bool prepare = (inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) ||
1058 		       ipv6_sk_rxinfo(sk);
1059 
1060 	if (prepare && skb_rtable(skb)) {
1061 		pktinfo->ipi_ifindex = inet_iif(skb);
1062 		pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);
1063 	} else {
1064 		pktinfo->ipi_ifindex = 0;
1065 		pktinfo->ipi_spec_dst.s_addr = 0;
1066 	}
1067 	skb_dst_drop(skb);
1068 }
1069 
1070 int ip_setsockopt(struct sock *sk, int level,
1071 		int optname, char __user *optval, unsigned int optlen)
1072 {
1073 	int err;
1074 
1075 	if (level != SOL_IP)
1076 		return -ENOPROTOOPT;
1077 
1078 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1079 #ifdef CONFIG_NETFILTER
1080 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1081 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1082 			optname != IP_IPSEC_POLICY &&
1083 			optname != IP_XFRM_POLICY &&
1084 			!ip_mroute_opt(optname)) {
1085 		lock_sock(sk);
1086 		err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
1087 		release_sock(sk);
1088 	}
1089 #endif
1090 	return err;
1091 }
1092 EXPORT_SYMBOL(ip_setsockopt);
1093 
1094 #ifdef CONFIG_COMPAT
1095 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
1096 			 char __user *optval, unsigned int optlen)
1097 {
1098 	int err;
1099 
1100 	if (level != SOL_IP)
1101 		return -ENOPROTOOPT;
1102 
1103 	if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
1104 		return compat_mc_setsockopt(sk, level, optname, optval, optlen,
1105 			ip_setsockopt);
1106 
1107 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1108 #ifdef CONFIG_NETFILTER
1109 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1110 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1111 			optname != IP_IPSEC_POLICY &&
1112 			optname != IP_XFRM_POLICY &&
1113 			!ip_mroute_opt(optname)) {
1114 		lock_sock(sk);
1115 		err = compat_nf_setsockopt(sk, PF_INET, optname,
1116 					   optval, optlen);
1117 		release_sock(sk);
1118 	}
1119 #endif
1120 	return err;
1121 }
1122 EXPORT_SYMBOL(compat_ip_setsockopt);
1123 #endif
1124 
1125 /*
1126  *	Get the options. Note for future reference. The GET of IP options gets
1127  *	the _received_ ones. The set sets the _sent_ ones.
1128  */
1129 
1130 static int do_ip_getsockopt(struct sock *sk, int level, int optname,
1131 			    char __user *optval, int __user *optlen, unsigned int flags)
1132 {
1133 	struct inet_sock *inet = inet_sk(sk);
1134 	int val;
1135 	int len;
1136 
1137 	if (level != SOL_IP)
1138 		return -EOPNOTSUPP;
1139 
1140 	if (ip_mroute_opt(optname))
1141 		return ip_mroute_getsockopt(sk, optname, optval, optlen);
1142 
1143 	if (get_user(len, optlen))
1144 		return -EFAULT;
1145 	if (len < 0)
1146 		return -EINVAL;
1147 
1148 	lock_sock(sk);
1149 
1150 	switch (optname) {
1151 	case IP_OPTIONS:
1152 	{
1153 		unsigned char optbuf[sizeof(struct ip_options)+40];
1154 		struct ip_options *opt = (struct ip_options *)optbuf;
1155 		struct ip_options_rcu *inet_opt;
1156 
1157 		inet_opt = rcu_dereference_protected(inet->inet_opt,
1158 						     sock_owned_by_user(sk));
1159 		opt->optlen = 0;
1160 		if (inet_opt)
1161 			memcpy(optbuf, &inet_opt->opt,
1162 			       sizeof(struct ip_options) +
1163 			       inet_opt->opt.optlen);
1164 		release_sock(sk);
1165 
1166 		if (opt->optlen == 0)
1167 			return put_user(0, optlen);
1168 
1169 		ip_options_undo(opt);
1170 
1171 		len = min_t(unsigned int, len, opt->optlen);
1172 		if (put_user(len, optlen))
1173 			return -EFAULT;
1174 		if (copy_to_user(optval, opt->__data, len))
1175 			return -EFAULT;
1176 		return 0;
1177 	}
1178 	case IP_PKTINFO:
1179 		val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
1180 		break;
1181 	case IP_RECVTTL:
1182 		val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
1183 		break;
1184 	case IP_RECVTOS:
1185 		val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
1186 		break;
1187 	case IP_RECVOPTS:
1188 		val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
1189 		break;
1190 	case IP_RETOPTS:
1191 		val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
1192 		break;
1193 	case IP_PASSSEC:
1194 		val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
1195 		break;
1196 	case IP_RECVORIGDSTADDR:
1197 		val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
1198 		break;
1199 	case IP_TOS:
1200 		val = inet->tos;
1201 		break;
1202 	case IP_TTL:
1203 		val = (inet->uc_ttl == -1 ?
1204 		       sysctl_ip_default_ttl :
1205 		       inet->uc_ttl);
1206 		break;
1207 	case IP_HDRINCL:
1208 		val = inet->hdrincl;
1209 		break;
1210 	case IP_NODEFRAG:
1211 		val = inet->nodefrag;
1212 		break;
1213 	case IP_MTU_DISCOVER:
1214 		val = inet->pmtudisc;
1215 		break;
1216 	case IP_MTU:
1217 	{
1218 		struct dst_entry *dst;
1219 		val = 0;
1220 		dst = sk_dst_get(sk);
1221 		if (dst) {
1222 			val = dst_mtu(dst);
1223 			dst_release(dst);
1224 		}
1225 		if (!val) {
1226 			release_sock(sk);
1227 			return -ENOTCONN;
1228 		}
1229 		break;
1230 	}
1231 	case IP_RECVERR:
1232 		val = inet->recverr;
1233 		break;
1234 	case IP_MULTICAST_TTL:
1235 		val = inet->mc_ttl;
1236 		break;
1237 	case IP_MULTICAST_LOOP:
1238 		val = inet->mc_loop;
1239 		break;
1240 	case IP_UNICAST_IF:
1241 		val = (__force int)htonl((__u32) inet->uc_index);
1242 		break;
1243 	case IP_MULTICAST_IF:
1244 	{
1245 		struct in_addr addr;
1246 		len = min_t(unsigned int, len, sizeof(struct in_addr));
1247 		addr.s_addr = inet->mc_addr;
1248 		release_sock(sk);
1249 
1250 		if (put_user(len, optlen))
1251 			return -EFAULT;
1252 		if (copy_to_user(optval, &addr, len))
1253 			return -EFAULT;
1254 		return 0;
1255 	}
1256 	case IP_MSFILTER:
1257 	{
1258 		struct ip_msfilter msf;
1259 		int err;
1260 
1261 		if (len < IP_MSFILTER_SIZE(0)) {
1262 			release_sock(sk);
1263 			return -EINVAL;
1264 		}
1265 		if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
1266 			release_sock(sk);
1267 			return -EFAULT;
1268 		}
1269 		err = ip_mc_msfget(sk, &msf,
1270 				   (struct ip_msfilter __user *)optval, optlen);
1271 		release_sock(sk);
1272 		return err;
1273 	}
1274 	case MCAST_MSFILTER:
1275 	{
1276 		struct group_filter gsf;
1277 		int err;
1278 
1279 		if (len < GROUP_FILTER_SIZE(0)) {
1280 			release_sock(sk);
1281 			return -EINVAL;
1282 		}
1283 		if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) {
1284 			release_sock(sk);
1285 			return -EFAULT;
1286 		}
1287 		err = ip_mc_gsfget(sk, &gsf,
1288 				   (struct group_filter __user *)optval,
1289 				   optlen);
1290 		release_sock(sk);
1291 		return err;
1292 	}
1293 	case IP_MULTICAST_ALL:
1294 		val = inet->mc_all;
1295 		break;
1296 	case IP_PKTOPTIONS:
1297 	{
1298 		struct msghdr msg;
1299 
1300 		release_sock(sk);
1301 
1302 		if (sk->sk_type != SOCK_STREAM)
1303 			return -ENOPROTOOPT;
1304 
1305 		msg.msg_control = optval;
1306 		msg.msg_controllen = len;
1307 		msg.msg_flags = flags;
1308 
1309 		if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
1310 			struct in_pktinfo info;
1311 
1312 			info.ipi_addr.s_addr = inet->inet_rcv_saddr;
1313 			info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
1314 			info.ipi_ifindex = inet->mc_index;
1315 			put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
1316 		}
1317 		if (inet->cmsg_flags & IP_CMSG_TTL) {
1318 			int hlim = inet->mc_ttl;
1319 			put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
1320 		}
1321 		if (inet->cmsg_flags & IP_CMSG_TOS) {
1322 			int tos = inet->rcv_tos;
1323 			put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
1324 		}
1325 		len -= msg.msg_controllen;
1326 		return put_user(len, optlen);
1327 	}
1328 	case IP_FREEBIND:
1329 		val = inet->freebind;
1330 		break;
1331 	case IP_TRANSPARENT:
1332 		val = inet->transparent;
1333 		break;
1334 	case IP_MINTTL:
1335 		val = inet->min_ttl;
1336 		break;
1337 	default:
1338 		release_sock(sk);
1339 		return -ENOPROTOOPT;
1340 	}
1341 	release_sock(sk);
1342 
1343 	if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
1344 		unsigned char ucval = (unsigned char)val;
1345 		len = 1;
1346 		if (put_user(len, optlen))
1347 			return -EFAULT;
1348 		if (copy_to_user(optval, &ucval, 1))
1349 			return -EFAULT;
1350 	} else {
1351 		len = min_t(unsigned int, sizeof(int), len);
1352 		if (put_user(len, optlen))
1353 			return -EFAULT;
1354 		if (copy_to_user(optval, &val, len))
1355 			return -EFAULT;
1356 	}
1357 	return 0;
1358 }
1359 
1360 int ip_getsockopt(struct sock *sk, int level,
1361 		  int optname, char __user *optval, int __user *optlen)
1362 {
1363 	int err;
1364 
1365 	err = do_ip_getsockopt(sk, level, optname, optval, optlen, 0);
1366 #ifdef CONFIG_NETFILTER
1367 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1368 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1369 			!ip_mroute_opt(optname)) {
1370 		int len;
1371 
1372 		if (get_user(len, optlen))
1373 			return -EFAULT;
1374 
1375 		lock_sock(sk);
1376 		err = nf_getsockopt(sk, PF_INET, optname, optval,
1377 				&len);
1378 		release_sock(sk);
1379 		if (err >= 0)
1380 			err = put_user(len, optlen);
1381 		return err;
1382 	}
1383 #endif
1384 	return err;
1385 }
1386 EXPORT_SYMBOL(ip_getsockopt);
1387 
1388 #ifdef CONFIG_COMPAT
1389 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
1390 			 char __user *optval, int __user *optlen)
1391 {
1392 	int err;
1393 
1394 	if (optname == MCAST_MSFILTER)
1395 		return compat_mc_getsockopt(sk, level, optname, optval, optlen,
1396 			ip_getsockopt);
1397 
1398 	err = do_ip_getsockopt(sk, level, optname, optval, optlen,
1399 		MSG_CMSG_COMPAT);
1400 
1401 #ifdef CONFIG_NETFILTER
1402 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1403 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1404 			!ip_mroute_opt(optname)) {
1405 		int len;
1406 
1407 		if (get_user(len, optlen))
1408 			return -EFAULT;
1409 
1410 		lock_sock(sk);
1411 		err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len);
1412 		release_sock(sk);
1413 		if (err >= 0)
1414 			err = put_user(len, optlen);
1415 		return err;
1416 	}
1417 #endif
1418 	return err;
1419 }
1420 EXPORT_SYMBOL(compat_ip_getsockopt);
1421 #endif
1422