xref: /kernel/linux/linux-6.6/net/ipv6/raw.c (revision 62306a36)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *	RAW sockets for IPv6
4 *	Linux INET6 implementation
5 *
6 *	Authors:
7 *	Pedro Roque		<roque@di.fc.ul.pt>
8 *
9 *	Adapted from linux/net/ipv4/raw.c
10 *
11 *	Fixes:
12 *	Hideaki YOSHIFUJI	:	sin6_scope_id support
13 *	YOSHIFUJI,H.@USAGI	:	raw checksum (RFC2292(bis) compliance)
14 *	Kazunori MIYAZAWA @USAGI:	change process style to use ip6_append_data
15 */
16
17#include <linux/errno.h>
18#include <linux/types.h>
19#include <linux/socket.h>
20#include <linux/slab.h>
21#include <linux/sockios.h>
22#include <linux/net.h>
23#include <linux/in6.h>
24#include <linux/netdevice.h>
25#include <linux/if_arp.h>
26#include <linux/icmpv6.h>
27#include <linux/netfilter.h>
28#include <linux/netfilter_ipv6.h>
29#include <linux/skbuff.h>
30#include <linux/compat.h>
31#include <linux/uaccess.h>
32#include <asm/ioctls.h>
33
34#include <net/net_namespace.h>
35#include <net/ip.h>
36#include <net/sock.h>
37#include <net/snmp.h>
38
39#include <net/ipv6.h>
40#include <net/ndisc.h>
41#include <net/protocol.h>
42#include <net/ip6_route.h>
43#include <net/ip6_checksum.h>
44#include <net/addrconf.h>
45#include <net/transp_v6.h>
46#include <net/udp.h>
47#include <net/inet_common.h>
48#include <net/tcp_states.h>
49#if IS_ENABLED(CONFIG_IPV6_MIP6)
50#include <net/mip6.h>
51#endif
52#include <linux/mroute6.h>
53
54#include <net/raw.h>
55#include <net/rawv6.h>
56#include <net/xfrm.h>
57
58#include <linux/proc_fs.h>
59#include <linux/seq_file.h>
60#include <linux/export.h>
61
62#define	ICMPV6_HDRLEN	4	/* ICMPv6 header, RFC 4443 Section 2.1 */
63
64struct raw_hashinfo raw_v6_hashinfo;
65EXPORT_SYMBOL_GPL(raw_v6_hashinfo);
66
67bool raw_v6_match(struct net *net, const struct sock *sk, unsigned short num,
68		  const struct in6_addr *loc_addr,
69		  const struct in6_addr *rmt_addr, int dif, int sdif)
70{
71	if (inet_sk(sk)->inet_num != num ||
72	    !net_eq(sock_net(sk), net) ||
73	    (!ipv6_addr_any(&sk->sk_v6_daddr) &&
74	     !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
75	    !raw_sk_bound_dev_eq(net, sk->sk_bound_dev_if,
76				 dif, sdif))
77		return false;
78
79	if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
80	    ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr) ||
81	    (ipv6_addr_is_multicast(loc_addr) &&
82	     inet6_mc_check(sk, loc_addr, rmt_addr)))
83		return true;
84
85	return false;
86}
87EXPORT_SYMBOL_GPL(raw_v6_match);
88
89/*
90 *	0 - deliver
91 *	1 - block
92 */
93static int icmpv6_filter(const struct sock *sk, const struct sk_buff *skb)
94{
95	struct icmp6hdr _hdr;
96	const struct icmp6hdr *hdr;
97
98	/* We require only the four bytes of the ICMPv6 header, not any
99	 * additional bytes of message body in "struct icmp6hdr".
100	 */
101	hdr = skb_header_pointer(skb, skb_transport_offset(skb),
102				 ICMPV6_HDRLEN, &_hdr);
103	if (hdr) {
104		const __u32 *data = &raw6_sk(sk)->filter.data[0];
105		unsigned int type = hdr->icmp6_type;
106
107		return (data[type >> 5] & (1U << (type & 31))) != 0;
108	}
109	return 1;
110}
111
112#if IS_ENABLED(CONFIG_IPV6_MIP6)
113typedef int mh_filter_t(struct sock *sock, struct sk_buff *skb);
114
115static mh_filter_t __rcu *mh_filter __read_mostly;
116
117int rawv6_mh_filter_register(mh_filter_t filter)
118{
119	rcu_assign_pointer(mh_filter, filter);
120	return 0;
121}
122EXPORT_SYMBOL(rawv6_mh_filter_register);
123
124int rawv6_mh_filter_unregister(mh_filter_t filter)
125{
126	RCU_INIT_POINTER(mh_filter, NULL);
127	synchronize_rcu();
128	return 0;
129}
130EXPORT_SYMBOL(rawv6_mh_filter_unregister);
131
132#endif
133
134/*
135 *	demultiplex raw sockets.
136 *	(should consider queueing the skb in the sock receive_queue
137 *	without calling rawv6.c)
138 *
139 *	Caller owns SKB so we must make clones.
140 */
141static bool ipv6_raw_deliver(struct sk_buff *skb, int nexthdr)
142{
143	struct net *net = dev_net(skb->dev);
144	const struct in6_addr *saddr;
145	const struct in6_addr *daddr;
146	struct hlist_head *hlist;
147	struct sock *sk;
148	bool delivered = false;
149	__u8 hash;
150
151	saddr = &ipv6_hdr(skb)->saddr;
152	daddr = saddr + 1;
153
154	hash = raw_hashfunc(net, nexthdr);
155	hlist = &raw_v6_hashinfo.ht[hash];
156	rcu_read_lock();
157	sk_for_each_rcu(sk, hlist) {
158		int filtered;
159
160		if (!raw_v6_match(net, sk, nexthdr, daddr, saddr,
161				  inet6_iif(skb), inet6_sdif(skb)))
162			continue;
163		delivered = true;
164		switch (nexthdr) {
165		case IPPROTO_ICMPV6:
166			filtered = icmpv6_filter(sk, skb);
167			break;
168
169#if IS_ENABLED(CONFIG_IPV6_MIP6)
170		case IPPROTO_MH:
171		{
172			/* XXX: To validate MH only once for each packet,
173			 * this is placed here. It should be after checking
174			 * xfrm policy, however it doesn't. The checking xfrm
175			 * policy is placed in rawv6_rcv() because it is
176			 * required for each socket.
177			 */
178			mh_filter_t *filter;
179
180			filter = rcu_dereference(mh_filter);
181			filtered = filter ? (*filter)(sk, skb) : 0;
182			break;
183		}
184#endif
185		default:
186			filtered = 0;
187			break;
188		}
189
190		if (filtered < 0)
191			break;
192		if (filtered == 0) {
193			struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC);
194
195			/* Not releasing hash table! */
196			if (clone)
197				rawv6_rcv(sk, clone);
198		}
199	}
200	rcu_read_unlock();
201	return delivered;
202}
203
204bool raw6_local_deliver(struct sk_buff *skb, int nexthdr)
205{
206	return ipv6_raw_deliver(skb, nexthdr);
207}
208
209/* This cleans up af_inet6 a bit. -DaveM */
210static int rawv6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
211{
212	struct inet_sock *inet = inet_sk(sk);
213	struct ipv6_pinfo *np = inet6_sk(sk);
214	struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
215	__be32 v4addr = 0;
216	int addr_type;
217	int err;
218
219	if (addr_len < SIN6_LEN_RFC2133)
220		return -EINVAL;
221
222	if (addr->sin6_family != AF_INET6)
223		return -EINVAL;
224
225	addr_type = ipv6_addr_type(&addr->sin6_addr);
226
227	/* Raw sockets are IPv6 only */
228	if (addr_type == IPV6_ADDR_MAPPED)
229		return -EADDRNOTAVAIL;
230
231	lock_sock(sk);
232
233	err = -EINVAL;
234	if (sk->sk_state != TCP_CLOSE)
235		goto out;
236
237	rcu_read_lock();
238	/* Check if the address belongs to the host. */
239	if (addr_type != IPV6_ADDR_ANY) {
240		struct net_device *dev = NULL;
241
242		if (__ipv6_addr_needs_scope_id(addr_type)) {
243			if (addr_len >= sizeof(struct sockaddr_in6) &&
244			    addr->sin6_scope_id) {
245				/* Override any existing binding, if another
246				 * one is supplied by user.
247				 */
248				sk->sk_bound_dev_if = addr->sin6_scope_id;
249			}
250
251			/* Binding to link-local address requires an interface */
252			if (!sk->sk_bound_dev_if)
253				goto out_unlock;
254		}
255
256		if (sk->sk_bound_dev_if) {
257			err = -ENODEV;
258			dev = dev_get_by_index_rcu(sock_net(sk),
259						   sk->sk_bound_dev_if);
260			if (!dev)
261				goto out_unlock;
262		}
263
264		/* ipv4 addr of the socket is invalid.  Only the
265		 * unspecified and mapped address have a v4 equivalent.
266		 */
267		v4addr = LOOPBACK4_IPV6;
268		if (!(addr_type & IPV6_ADDR_MULTICAST) &&
269		    !ipv6_can_nonlocal_bind(sock_net(sk), inet)) {
270			err = -EADDRNOTAVAIL;
271			if (!ipv6_chk_addr(sock_net(sk), &addr->sin6_addr,
272					   dev, 0)) {
273				goto out_unlock;
274			}
275		}
276	}
277
278	inet->inet_rcv_saddr = inet->inet_saddr = v4addr;
279	sk->sk_v6_rcv_saddr = addr->sin6_addr;
280	if (!(addr_type & IPV6_ADDR_MULTICAST))
281		np->saddr = addr->sin6_addr;
282	err = 0;
283out_unlock:
284	rcu_read_unlock();
285out:
286	release_sock(sk);
287	return err;
288}
289
290static void rawv6_err(struct sock *sk, struct sk_buff *skb,
291	       struct inet6_skb_parm *opt,
292	       u8 type, u8 code, int offset, __be32 info)
293{
294	struct ipv6_pinfo *np = inet6_sk(sk);
295	int err;
296	int harderr;
297
298	/* Report error on raw socket, if:
299	   1. User requested recverr.
300	   2. Socket is connected (otherwise the error indication
301	      is useless without recverr and error is hard.
302	 */
303	if (!np->recverr && sk->sk_state != TCP_ESTABLISHED)
304		return;
305
306	harderr = icmpv6_err_convert(type, code, &err);
307	if (type == ICMPV6_PKT_TOOBIG) {
308		ip6_sk_update_pmtu(skb, sk, info);
309		harderr = (np->pmtudisc == IPV6_PMTUDISC_DO);
310	}
311	if (type == NDISC_REDIRECT) {
312		ip6_sk_redirect(skb, sk);
313		return;
314	}
315	if (np->recverr) {
316		u8 *payload = skb->data;
317		if (!inet_test_bit(HDRINCL, sk))
318			payload += offset;
319		ipv6_icmp_error(sk, skb, err, 0, ntohl(info), payload);
320	}
321
322	if (np->recverr || harderr) {
323		sk->sk_err = err;
324		sk_error_report(sk);
325	}
326}
327
328void raw6_icmp_error(struct sk_buff *skb, int nexthdr,
329		u8 type, u8 code, int inner_offset, __be32 info)
330{
331	struct net *net = dev_net(skb->dev);
332	struct hlist_head *hlist;
333	struct sock *sk;
334	int hash;
335
336	hash = raw_hashfunc(net, nexthdr);
337	hlist = &raw_v6_hashinfo.ht[hash];
338	rcu_read_lock();
339	sk_for_each_rcu(sk, hlist) {
340		/* Note: ipv6_hdr(skb) != skb->data */
341		const struct ipv6hdr *ip6h = (const struct ipv6hdr *)skb->data;
342
343		if (!raw_v6_match(net, sk, nexthdr, &ip6h->saddr, &ip6h->daddr,
344				  inet6_iif(skb), inet6_iif(skb)))
345			continue;
346		rawv6_err(sk, skb, NULL, type, code, inner_offset, info);
347	}
348	rcu_read_unlock();
349}
350
351static inline int rawv6_rcv_skb(struct sock *sk, struct sk_buff *skb)
352{
353	enum skb_drop_reason reason;
354
355	if ((raw6_sk(sk)->checksum || rcu_access_pointer(sk->sk_filter)) &&
356	    skb_checksum_complete(skb)) {
357		atomic_inc(&sk->sk_drops);
358		kfree_skb_reason(skb, SKB_DROP_REASON_SKB_CSUM);
359		return NET_RX_DROP;
360	}
361
362	/* Charge it to the socket. */
363	skb_dst_drop(skb);
364	if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0) {
365		kfree_skb_reason(skb, reason);
366		return NET_RX_DROP;
367	}
368
369	return 0;
370}
371
372/*
373 *	This is next to useless...
374 *	if we demultiplex in network layer we don't need the extra call
375 *	just to queue the skb...
376 *	maybe we could have the network decide upon a hint if it
377 *	should call raw_rcv for demultiplexing
378 */
379int rawv6_rcv(struct sock *sk, struct sk_buff *skb)
380{
381	struct inet_sock *inet = inet_sk(sk);
382	struct raw6_sock *rp = raw6_sk(sk);
383
384	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
385		atomic_inc(&sk->sk_drops);
386		kfree_skb_reason(skb, SKB_DROP_REASON_XFRM_POLICY);
387		return NET_RX_DROP;
388	}
389	nf_reset_ct(skb);
390
391	if (!rp->checksum)
392		skb->ip_summed = CHECKSUM_UNNECESSARY;
393
394	if (skb->ip_summed == CHECKSUM_COMPLETE) {
395		skb_postpull_rcsum(skb, skb_network_header(skb),
396				   skb_network_header_len(skb));
397		if (!csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
398				     &ipv6_hdr(skb)->daddr,
399				     skb->len, inet->inet_num, skb->csum))
400			skb->ip_summed = CHECKSUM_UNNECESSARY;
401	}
402	if (!skb_csum_unnecessary(skb))
403		skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
404							 &ipv6_hdr(skb)->daddr,
405							 skb->len,
406							 inet->inet_num, 0));
407
408	if (inet_test_bit(HDRINCL, sk)) {
409		if (skb_checksum_complete(skb)) {
410			atomic_inc(&sk->sk_drops);
411			kfree_skb_reason(skb, SKB_DROP_REASON_SKB_CSUM);
412			return NET_RX_DROP;
413		}
414	}
415
416	rawv6_rcv_skb(sk, skb);
417	return 0;
418}
419
420
421/*
422 *	This should be easy, if there is something there
423 *	we return it, otherwise we block.
424 */
425
426static int rawv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
427			 int flags, int *addr_len)
428{
429	struct ipv6_pinfo *np = inet6_sk(sk);
430	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
431	struct sk_buff *skb;
432	size_t copied;
433	int err;
434
435	if (flags & MSG_OOB)
436		return -EOPNOTSUPP;
437
438	if (flags & MSG_ERRQUEUE)
439		return ipv6_recv_error(sk, msg, len, addr_len);
440
441	if (np->rxpmtu && np->rxopt.bits.rxpmtu)
442		return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
443
444	skb = skb_recv_datagram(sk, flags, &err);
445	if (!skb)
446		goto out;
447
448	copied = skb->len;
449	if (copied > len) {
450		copied = len;
451		msg->msg_flags |= MSG_TRUNC;
452	}
453
454	if (skb_csum_unnecessary(skb)) {
455		err = skb_copy_datagram_msg(skb, 0, msg, copied);
456	} else if (msg->msg_flags&MSG_TRUNC) {
457		if (__skb_checksum_complete(skb))
458			goto csum_copy_err;
459		err = skb_copy_datagram_msg(skb, 0, msg, copied);
460	} else {
461		err = skb_copy_and_csum_datagram_msg(skb, 0, msg);
462		if (err == -EINVAL)
463			goto csum_copy_err;
464	}
465	if (err)
466		goto out_free;
467
468	/* Copy the address. */
469	if (sin6) {
470		sin6->sin6_family = AF_INET6;
471		sin6->sin6_port = 0;
472		sin6->sin6_addr = ipv6_hdr(skb)->saddr;
473		sin6->sin6_flowinfo = 0;
474		sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr,
475							  inet6_iif(skb));
476		*addr_len = sizeof(*sin6);
477	}
478
479	sock_recv_cmsgs(msg, sk, skb);
480
481	if (np->rxopt.all)
482		ip6_datagram_recv_ctl(sk, msg, skb);
483
484	err = copied;
485	if (flags & MSG_TRUNC)
486		err = skb->len;
487
488out_free:
489	skb_free_datagram(sk, skb);
490out:
491	return err;
492
493csum_copy_err:
494	skb_kill_datagram(sk, skb, flags);
495
496	/* Error for blocking case is chosen to masquerade
497	   as some normal condition.
498	 */
499	err = (flags&MSG_DONTWAIT) ? -EAGAIN : -EHOSTUNREACH;
500	goto out;
501}
502
503static int rawv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
504				     struct raw6_sock *rp)
505{
506	struct ipv6_txoptions *opt;
507	struct sk_buff *skb;
508	int err = 0;
509	int offset;
510	int len;
511	int total_len;
512	__wsum tmp_csum;
513	__sum16 csum;
514
515	if (!rp->checksum)
516		goto send;
517
518	skb = skb_peek(&sk->sk_write_queue);
519	if (!skb)
520		goto out;
521
522	offset = rp->offset;
523	total_len = inet_sk(sk)->cork.base.length;
524	opt = inet6_sk(sk)->cork.opt;
525	total_len -= opt ? opt->opt_flen : 0;
526
527	if (offset >= total_len - 1) {
528		err = -EINVAL;
529		ip6_flush_pending_frames(sk);
530		goto out;
531	}
532
533	/* should be check HW csum miyazawa */
534	if (skb_queue_len(&sk->sk_write_queue) == 1) {
535		/*
536		 * Only one fragment on the socket.
537		 */
538		tmp_csum = skb->csum;
539	} else {
540		struct sk_buff *csum_skb = NULL;
541		tmp_csum = 0;
542
543		skb_queue_walk(&sk->sk_write_queue, skb) {
544			tmp_csum = csum_add(tmp_csum, skb->csum);
545
546			if (csum_skb)
547				continue;
548
549			len = skb->len - skb_transport_offset(skb);
550			if (offset >= len) {
551				offset -= len;
552				continue;
553			}
554
555			csum_skb = skb;
556		}
557
558		skb = csum_skb;
559	}
560
561	offset += skb_transport_offset(skb);
562	err = skb_copy_bits(skb, offset, &csum, 2);
563	if (err < 0) {
564		ip6_flush_pending_frames(sk);
565		goto out;
566	}
567
568	/* in case cksum was not initialized */
569	if (unlikely(csum))
570		tmp_csum = csum_sub(tmp_csum, csum_unfold(csum));
571
572	csum = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
573			       total_len, fl6->flowi6_proto, tmp_csum);
574
575	if (csum == 0 && fl6->flowi6_proto == IPPROTO_UDP)
576		csum = CSUM_MANGLED_0;
577
578	BUG_ON(skb_store_bits(skb, offset, &csum, 2));
579
580send:
581	err = ip6_push_pending_frames(sk);
582out:
583	return err;
584}
585
586static int rawv6_send_hdrinc(struct sock *sk, struct msghdr *msg, int length,
587			struct flowi6 *fl6, struct dst_entry **dstp,
588			unsigned int flags, const struct sockcm_cookie *sockc)
589{
590	struct ipv6_pinfo *np = inet6_sk(sk);
591	struct net *net = sock_net(sk);
592	struct ipv6hdr *iph;
593	struct sk_buff *skb;
594	int err;
595	struct rt6_info *rt = (struct rt6_info *)*dstp;
596	int hlen = LL_RESERVED_SPACE(rt->dst.dev);
597	int tlen = rt->dst.dev->needed_tailroom;
598
599	if (length > rt->dst.dev->mtu) {
600		ipv6_local_error(sk, EMSGSIZE, fl6, rt->dst.dev->mtu);
601		return -EMSGSIZE;
602	}
603	if (length < sizeof(struct ipv6hdr))
604		return -EINVAL;
605	if (flags&MSG_PROBE)
606		goto out;
607
608	skb = sock_alloc_send_skb(sk,
609				  length + hlen + tlen + 15,
610				  flags & MSG_DONTWAIT, &err);
611	if (!skb)
612		goto error;
613	skb_reserve(skb, hlen);
614
615	skb->protocol = htons(ETH_P_IPV6);
616	skb->priority = READ_ONCE(sk->sk_priority);
617	skb->mark = sockc->mark;
618	skb->tstamp = sockc->transmit_time;
619
620	skb_put(skb, length);
621	skb_reset_network_header(skb);
622	iph = ipv6_hdr(skb);
623
624	skb->ip_summed = CHECKSUM_NONE;
625
626	skb_setup_tx_timestamp(skb, sockc->tsflags);
627
628	if (flags & MSG_CONFIRM)
629		skb_set_dst_pending_confirm(skb, 1);
630
631	skb->transport_header = skb->network_header;
632	err = memcpy_from_msg(iph, msg, length);
633	if (err) {
634		err = -EFAULT;
635		kfree_skb(skb);
636		goto error;
637	}
638
639	skb_dst_set(skb, &rt->dst);
640	*dstp = NULL;
641
642	/* if egress device is enslaved to an L3 master device pass the
643	 * skb to its handler for processing
644	 */
645	skb = l3mdev_ip6_out(sk, skb);
646	if (unlikely(!skb))
647		return 0;
648
649	/* Acquire rcu_read_lock() in case we need to use rt->rt6i_idev
650	 * in the error path. Since skb has been freed, the dst could
651	 * have been queued for deletion.
652	 */
653	rcu_read_lock();
654	IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);
655	err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk, skb,
656		      NULL, rt->dst.dev, dst_output);
657	if (err > 0)
658		err = net_xmit_errno(err);
659	if (err) {
660		IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
661		rcu_read_unlock();
662		goto error_check;
663	}
664	rcu_read_unlock();
665out:
666	return 0;
667
668error:
669	IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
670error_check:
671	if (err == -ENOBUFS && !np->recverr)
672		err = 0;
673	return err;
674}
675
676struct raw6_frag_vec {
677	struct msghdr *msg;
678	int hlen;
679	char c[4];
680};
681
682static int rawv6_probe_proto_opt(struct raw6_frag_vec *rfv, struct flowi6 *fl6)
683{
684	int err = 0;
685	switch (fl6->flowi6_proto) {
686	case IPPROTO_ICMPV6:
687		rfv->hlen = 2;
688		err = memcpy_from_msg(rfv->c, rfv->msg, rfv->hlen);
689		if (!err) {
690			fl6->fl6_icmp_type = rfv->c[0];
691			fl6->fl6_icmp_code = rfv->c[1];
692		}
693		break;
694	case IPPROTO_MH:
695		rfv->hlen = 4;
696		err = memcpy_from_msg(rfv->c, rfv->msg, rfv->hlen);
697		if (!err)
698			fl6->fl6_mh_type = rfv->c[2];
699	}
700	return err;
701}
702
703static int raw6_getfrag(void *from, char *to, int offset, int len, int odd,
704		       struct sk_buff *skb)
705{
706	struct raw6_frag_vec *rfv = from;
707
708	if (offset < rfv->hlen) {
709		int copy = min(rfv->hlen - offset, len);
710
711		if (skb->ip_summed == CHECKSUM_PARTIAL)
712			memcpy(to, rfv->c + offset, copy);
713		else
714			skb->csum = csum_block_add(
715				skb->csum,
716				csum_partial_copy_nocheck(rfv->c + offset,
717							  to, copy),
718				odd);
719
720		odd = 0;
721		offset += copy;
722		to += copy;
723		len -= copy;
724
725		if (!len)
726			return 0;
727	}
728
729	offset -= rfv->hlen;
730
731	return ip_generic_getfrag(rfv->msg, to, offset, len, odd, skb);
732}
733
734static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
735{
736	struct ipv6_txoptions *opt_to_free = NULL;
737	struct ipv6_txoptions opt_space;
738	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
739	struct in6_addr *daddr, *final_p, final;
740	struct inet_sock *inet = inet_sk(sk);
741	struct ipv6_pinfo *np = inet6_sk(sk);
742	struct raw6_sock *rp = raw6_sk(sk);
743	struct ipv6_txoptions *opt = NULL;
744	struct ip6_flowlabel *flowlabel = NULL;
745	struct dst_entry *dst = NULL;
746	struct raw6_frag_vec rfv;
747	struct flowi6 fl6;
748	struct ipcm6_cookie ipc6;
749	int addr_len = msg->msg_namelen;
750	int hdrincl;
751	u16 proto;
752	int err;
753
754	/* Rough check on arithmetic overflow,
755	   better check is made in ip6_append_data().
756	 */
757	if (len > INT_MAX)
758		return -EMSGSIZE;
759
760	/* Mirror BSD error message compatibility */
761	if (msg->msg_flags & MSG_OOB)
762		return -EOPNOTSUPP;
763
764	hdrincl = inet_test_bit(HDRINCL, sk);
765
766	/*
767	 *	Get and verify the address.
768	 */
769	memset(&fl6, 0, sizeof(fl6));
770
771	fl6.flowi6_mark = READ_ONCE(sk->sk_mark);
772	fl6.flowi6_uid = sk->sk_uid;
773
774	ipcm6_init(&ipc6);
775	ipc6.sockc.tsflags = READ_ONCE(sk->sk_tsflags);
776	ipc6.sockc.mark = fl6.flowi6_mark;
777
778	if (sin6) {
779		if (addr_len < SIN6_LEN_RFC2133)
780			return -EINVAL;
781
782		if (sin6->sin6_family && sin6->sin6_family != AF_INET6)
783			return -EAFNOSUPPORT;
784
785		/* port is the proto value [0..255] carried in nexthdr */
786		proto = ntohs(sin6->sin6_port);
787
788		if (!proto)
789			proto = inet->inet_num;
790		else if (proto != inet->inet_num &&
791			 inet->inet_num != IPPROTO_RAW)
792			return -EINVAL;
793
794		if (proto > 255)
795			return -EINVAL;
796
797		daddr = &sin6->sin6_addr;
798		if (np->sndflow) {
799			fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
800			if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
801				flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
802				if (IS_ERR(flowlabel))
803					return -EINVAL;
804			}
805		}
806
807		/*
808		 * Otherwise it will be difficult to maintain
809		 * sk->sk_dst_cache.
810		 */
811		if (sk->sk_state == TCP_ESTABLISHED &&
812		    ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
813			daddr = &sk->sk_v6_daddr;
814
815		if (addr_len >= sizeof(struct sockaddr_in6) &&
816		    sin6->sin6_scope_id &&
817		    __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
818			fl6.flowi6_oif = sin6->sin6_scope_id;
819	} else {
820		if (sk->sk_state != TCP_ESTABLISHED)
821			return -EDESTADDRREQ;
822
823		proto = inet->inet_num;
824		daddr = &sk->sk_v6_daddr;
825		fl6.flowlabel = np->flow_label;
826	}
827
828	if (fl6.flowi6_oif == 0)
829		fl6.flowi6_oif = sk->sk_bound_dev_if;
830
831	if (msg->msg_controllen) {
832		opt = &opt_space;
833		memset(opt, 0, sizeof(struct ipv6_txoptions));
834		opt->tot_len = sizeof(struct ipv6_txoptions);
835		ipc6.opt = opt;
836
837		err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6);
838		if (err < 0) {
839			fl6_sock_release(flowlabel);
840			return err;
841		}
842		if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
843			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
844			if (IS_ERR(flowlabel))
845				return -EINVAL;
846		}
847		if (!(opt->opt_nflen|opt->opt_flen))
848			opt = NULL;
849	}
850	if (!opt) {
851		opt = txopt_get(np);
852		opt_to_free = opt;
853	}
854	if (flowlabel)
855		opt = fl6_merge_options(&opt_space, flowlabel, opt);
856	opt = ipv6_fixup_options(&opt_space, opt);
857
858	fl6.flowi6_proto = proto;
859	fl6.flowi6_mark = ipc6.sockc.mark;
860
861	if (!hdrincl) {
862		rfv.msg = msg;
863		rfv.hlen = 0;
864		err = rawv6_probe_proto_opt(&rfv, &fl6);
865		if (err)
866			goto out;
867	}
868
869	if (!ipv6_addr_any(daddr))
870		fl6.daddr = *daddr;
871	else
872		fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
873	if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
874		fl6.saddr = np->saddr;
875
876	final_p = fl6_update_dst(&fl6, opt, &final);
877
878	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
879		fl6.flowi6_oif = np->mcast_oif;
880	else if (!fl6.flowi6_oif)
881		fl6.flowi6_oif = np->ucast_oif;
882	security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
883
884	if (hdrincl)
885		fl6.flowi6_flags |= FLOWI_FLAG_KNOWN_NH;
886
887	if (ipc6.tclass < 0)
888		ipc6.tclass = np->tclass;
889
890	fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
891
892	dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
893	if (IS_ERR(dst)) {
894		err = PTR_ERR(dst);
895		goto out;
896	}
897	if (ipc6.hlimit < 0)
898		ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
899
900	if (ipc6.dontfrag < 0)
901		ipc6.dontfrag = np->dontfrag;
902
903	if (msg->msg_flags&MSG_CONFIRM)
904		goto do_confirm;
905
906back_from_confirm:
907	if (hdrincl)
908		err = rawv6_send_hdrinc(sk, msg, len, &fl6, &dst,
909					msg->msg_flags, &ipc6.sockc);
910	else {
911		ipc6.opt = opt;
912		lock_sock(sk);
913		err = ip6_append_data(sk, raw6_getfrag, &rfv,
914			len, 0, &ipc6, &fl6, (struct rt6_info *)dst,
915			msg->msg_flags);
916
917		if (err)
918			ip6_flush_pending_frames(sk);
919		else if (!(msg->msg_flags & MSG_MORE))
920			err = rawv6_push_pending_frames(sk, &fl6, rp);
921		release_sock(sk);
922	}
923done:
924	dst_release(dst);
925out:
926	fl6_sock_release(flowlabel);
927	txopt_put(opt_to_free);
928	return err < 0 ? err : len;
929do_confirm:
930	if (msg->msg_flags & MSG_PROBE)
931		dst_confirm_neigh(dst, &fl6.daddr);
932	if (!(msg->msg_flags & MSG_PROBE) || len)
933		goto back_from_confirm;
934	err = 0;
935	goto done;
936}
937
938static int rawv6_seticmpfilter(struct sock *sk, int level, int optname,
939			       sockptr_t optval, int optlen)
940{
941	switch (optname) {
942	case ICMPV6_FILTER:
943		if (optlen > sizeof(struct icmp6_filter))
944			optlen = sizeof(struct icmp6_filter);
945		if (copy_from_sockptr(&raw6_sk(sk)->filter, optval, optlen))
946			return -EFAULT;
947		return 0;
948	default:
949		return -ENOPROTOOPT;
950	}
951
952	return 0;
953}
954
955static int rawv6_geticmpfilter(struct sock *sk, int level, int optname,
956			       char __user *optval, int __user *optlen)
957{
958	int len;
959
960	switch (optname) {
961	case ICMPV6_FILTER:
962		if (get_user(len, optlen))
963			return -EFAULT;
964		if (len < 0)
965			return -EINVAL;
966		if (len > sizeof(struct icmp6_filter))
967			len = sizeof(struct icmp6_filter);
968		if (put_user(len, optlen))
969			return -EFAULT;
970		if (copy_to_user(optval, &raw6_sk(sk)->filter, len))
971			return -EFAULT;
972		return 0;
973	default:
974		return -ENOPROTOOPT;
975	}
976
977	return 0;
978}
979
980
981static int do_rawv6_setsockopt(struct sock *sk, int level, int optname,
982			       sockptr_t optval, unsigned int optlen)
983{
984	struct raw6_sock *rp = raw6_sk(sk);
985	int val;
986
987	if (optlen < sizeof(val))
988		return -EINVAL;
989
990	if (copy_from_sockptr(&val, optval, sizeof(val)))
991		return -EFAULT;
992
993	switch (optname) {
994	case IPV6_HDRINCL:
995		if (sk->sk_type != SOCK_RAW)
996			return -EINVAL;
997		inet_assign_bit(HDRINCL, sk, val);
998		return 0;
999	case IPV6_CHECKSUM:
1000		if (inet_sk(sk)->inet_num == IPPROTO_ICMPV6 &&
1001		    level == IPPROTO_IPV6) {
1002			/*
1003			 * RFC3542 tells that IPV6_CHECKSUM socket
1004			 * option in the IPPROTO_IPV6 level is not
1005			 * allowed on ICMPv6 sockets.
1006			 * If you want to set it, use IPPROTO_RAW
1007			 * level IPV6_CHECKSUM socket option
1008			 * (Linux extension).
1009			 */
1010			return -EINVAL;
1011		}
1012
1013		/* You may get strange result with a positive odd offset;
1014		   RFC2292bis agrees with me. */
1015		if (val > 0 && (val&1))
1016			return -EINVAL;
1017		if (val < 0) {
1018			rp->checksum = 0;
1019		} else {
1020			rp->checksum = 1;
1021			rp->offset = val;
1022		}
1023
1024		return 0;
1025
1026	default:
1027		return -ENOPROTOOPT;
1028	}
1029}
1030
1031static int rawv6_setsockopt(struct sock *sk, int level, int optname,
1032			    sockptr_t optval, unsigned int optlen)
1033{
1034	switch (level) {
1035	case SOL_RAW:
1036		break;
1037
1038	case SOL_ICMPV6:
1039		if (inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
1040			return -EOPNOTSUPP;
1041		return rawv6_seticmpfilter(sk, level, optname, optval, optlen);
1042	case SOL_IPV6:
1043		if (optname == IPV6_CHECKSUM ||
1044		    optname == IPV6_HDRINCL)
1045			break;
1046		fallthrough;
1047	default:
1048		return ipv6_setsockopt(sk, level, optname, optval, optlen);
1049	}
1050
1051	return do_rawv6_setsockopt(sk, level, optname, optval, optlen);
1052}
1053
1054static int do_rawv6_getsockopt(struct sock *sk, int level, int optname,
1055			    char __user *optval, int __user *optlen)
1056{
1057	struct raw6_sock *rp = raw6_sk(sk);
1058	int val, len;
1059
1060	if (get_user(len, optlen))
1061		return -EFAULT;
1062
1063	switch (optname) {
1064	case IPV6_HDRINCL:
1065		val = inet_test_bit(HDRINCL, sk);
1066		break;
1067	case IPV6_CHECKSUM:
1068		/*
1069		 * We allow getsockopt() for IPPROTO_IPV6-level
1070		 * IPV6_CHECKSUM socket option on ICMPv6 sockets
1071		 * since RFC3542 is silent about it.
1072		 */
1073		if (rp->checksum == 0)
1074			val = -1;
1075		else
1076			val = rp->offset;
1077		break;
1078
1079	default:
1080		return -ENOPROTOOPT;
1081	}
1082
1083	len = min_t(unsigned int, sizeof(int), len);
1084
1085	if (put_user(len, optlen))
1086		return -EFAULT;
1087	if (copy_to_user(optval, &val, len))
1088		return -EFAULT;
1089	return 0;
1090}
1091
1092static int rawv6_getsockopt(struct sock *sk, int level, int optname,
1093			  char __user *optval, int __user *optlen)
1094{
1095	switch (level) {
1096	case SOL_RAW:
1097		break;
1098
1099	case SOL_ICMPV6:
1100		if (inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
1101			return -EOPNOTSUPP;
1102		return rawv6_geticmpfilter(sk, level, optname, optval, optlen);
1103	case SOL_IPV6:
1104		if (optname == IPV6_CHECKSUM ||
1105		    optname == IPV6_HDRINCL)
1106			break;
1107		fallthrough;
1108	default:
1109		return ipv6_getsockopt(sk, level, optname, optval, optlen);
1110	}
1111
1112	return do_rawv6_getsockopt(sk, level, optname, optval, optlen);
1113}
1114
1115static int rawv6_ioctl(struct sock *sk, int cmd, int *karg)
1116{
1117	switch (cmd) {
1118	case SIOCOUTQ: {
1119		*karg = sk_wmem_alloc_get(sk);
1120		return 0;
1121	}
1122	case SIOCINQ: {
1123		struct sk_buff *skb;
1124
1125		spin_lock_bh(&sk->sk_receive_queue.lock);
1126		skb = skb_peek(&sk->sk_receive_queue);
1127		if (skb)
1128			*karg = skb->len;
1129		else
1130			*karg = 0;
1131		spin_unlock_bh(&sk->sk_receive_queue.lock);
1132		return 0;
1133	}
1134
1135	default:
1136#ifdef CONFIG_IPV6_MROUTE
1137		return ip6mr_ioctl(sk, cmd, karg);
1138#else
1139		return -ENOIOCTLCMD;
1140#endif
1141	}
1142}
1143
1144#ifdef CONFIG_COMPAT
1145static int compat_rawv6_ioctl(struct sock *sk, unsigned int cmd, unsigned long arg)
1146{
1147	switch (cmd) {
1148	case SIOCOUTQ:
1149	case SIOCINQ:
1150		return -ENOIOCTLCMD;
1151	default:
1152#ifdef CONFIG_IPV6_MROUTE
1153		return ip6mr_compat_ioctl(sk, cmd, compat_ptr(arg));
1154#else
1155		return -ENOIOCTLCMD;
1156#endif
1157	}
1158}
1159#endif
1160
1161static void rawv6_close(struct sock *sk, long timeout)
1162{
1163	if (inet_sk(sk)->inet_num == IPPROTO_RAW)
1164		ip6_ra_control(sk, -1);
1165	ip6mr_sk_done(sk);
1166	sk_common_release(sk);
1167}
1168
1169static void raw6_destroy(struct sock *sk)
1170{
1171	lock_sock(sk);
1172	ip6_flush_pending_frames(sk);
1173	release_sock(sk);
1174}
1175
1176static int rawv6_init_sk(struct sock *sk)
1177{
1178	struct raw6_sock *rp = raw6_sk(sk);
1179
1180	switch (inet_sk(sk)->inet_num) {
1181	case IPPROTO_ICMPV6:
1182		rp->checksum = 1;
1183		rp->offset   = 2;
1184		break;
1185	case IPPROTO_MH:
1186		rp->checksum = 1;
1187		rp->offset   = 4;
1188		break;
1189	default:
1190		break;
1191	}
1192	return 0;
1193}
1194
1195struct proto rawv6_prot = {
1196	.name		   = "RAWv6",
1197	.owner		   = THIS_MODULE,
1198	.close		   = rawv6_close,
1199	.destroy	   = raw6_destroy,
1200	.connect	   = ip6_datagram_connect_v6_only,
1201	.disconnect	   = __udp_disconnect,
1202	.ioctl		   = rawv6_ioctl,
1203	.init		   = rawv6_init_sk,
1204	.setsockopt	   = rawv6_setsockopt,
1205	.getsockopt	   = rawv6_getsockopt,
1206	.sendmsg	   = rawv6_sendmsg,
1207	.recvmsg	   = rawv6_recvmsg,
1208	.bind		   = rawv6_bind,
1209	.backlog_rcv	   = rawv6_rcv_skb,
1210	.hash		   = raw_hash_sk,
1211	.unhash		   = raw_unhash_sk,
1212	.obj_size	   = sizeof(struct raw6_sock),
1213	.ipv6_pinfo_offset = offsetof(struct raw6_sock, inet6),
1214	.useroffset	   = offsetof(struct raw6_sock, filter),
1215	.usersize	   = sizeof_field(struct raw6_sock, filter),
1216	.h.raw_hash	   = &raw_v6_hashinfo,
1217#ifdef CONFIG_COMPAT
1218	.compat_ioctl	   = compat_rawv6_ioctl,
1219#endif
1220	.diag_destroy	   = raw_abort,
1221};
1222
1223#ifdef CONFIG_PROC_FS
1224static int raw6_seq_show(struct seq_file *seq, void *v)
1225{
1226	if (v == SEQ_START_TOKEN) {
1227		seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1228	} else {
1229		struct sock *sp = v;
1230		__u16 srcp  = inet_sk(sp)->inet_num;
1231		ip6_dgram_sock_seq_show(seq, v, srcp, 0,
1232					raw_seq_private(seq)->bucket);
1233	}
1234	return 0;
1235}
1236
1237static const struct seq_operations raw6_seq_ops = {
1238	.start =	raw_seq_start,
1239	.next =		raw_seq_next,
1240	.stop =		raw_seq_stop,
1241	.show =		raw6_seq_show,
1242};
1243
1244static int __net_init raw6_init_net(struct net *net)
1245{
1246	if (!proc_create_net_data("raw6", 0444, net->proc_net, &raw6_seq_ops,
1247			sizeof(struct raw_iter_state), &raw_v6_hashinfo))
1248		return -ENOMEM;
1249
1250	return 0;
1251}
1252
1253static void __net_exit raw6_exit_net(struct net *net)
1254{
1255	remove_proc_entry("raw6", net->proc_net);
1256}
1257
1258static struct pernet_operations raw6_net_ops = {
1259	.init = raw6_init_net,
1260	.exit = raw6_exit_net,
1261};
1262
1263int __init raw6_proc_init(void)
1264{
1265	return register_pernet_subsys(&raw6_net_ops);
1266}
1267
1268void raw6_proc_exit(void)
1269{
1270	unregister_pernet_subsys(&raw6_net_ops);
1271}
1272#endif	/* CONFIG_PROC_FS */
1273
1274/* Same as inet6_dgram_ops, sans udp_poll.  */
1275const struct proto_ops inet6_sockraw_ops = {
1276	.family		   = PF_INET6,
1277	.owner		   = THIS_MODULE,
1278	.release	   = inet6_release,
1279	.bind		   = inet6_bind,
1280	.connect	   = inet_dgram_connect,	/* ok		*/
1281	.socketpair	   = sock_no_socketpair,	/* a do nothing	*/
1282	.accept		   = sock_no_accept,		/* a do nothing	*/
1283	.getname	   = inet6_getname,
1284	.poll		   = datagram_poll,		/* ok		*/
1285	.ioctl		   = inet6_ioctl,		/* must change  */
1286	.gettstamp	   = sock_gettstamp,
1287	.listen		   = sock_no_listen,		/* ok		*/
1288	.shutdown	   = inet_shutdown,		/* ok		*/
1289	.setsockopt	   = sock_common_setsockopt,	/* ok		*/
1290	.getsockopt	   = sock_common_getsockopt,	/* ok		*/
1291	.sendmsg	   = inet_sendmsg,		/* ok		*/
1292	.recvmsg	   = sock_common_recvmsg,	/* ok		*/
1293	.mmap		   = sock_no_mmap,
1294#ifdef CONFIG_COMPAT
1295	.compat_ioctl	   = inet6_compat_ioctl,
1296#endif
1297};
1298
1299static struct inet_protosw rawv6_protosw = {
1300	.type		= SOCK_RAW,
1301	.protocol	= IPPROTO_IP,	/* wild card */
1302	.prot		= &rawv6_prot,
1303	.ops		= &inet6_sockraw_ops,
1304	.flags		= INET_PROTOSW_REUSE,
1305};
1306
1307int __init rawv6_init(void)
1308{
1309	return inet6_register_protosw(&rawv6_protosw);
1310}
1311
1312void rawv6_exit(void)
1313{
1314	inet6_unregister_protosw(&rawv6_protosw);
1315}
1316