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
164		if (atomic_read(&sk->sk_rmem_alloc) >=
165		    READ_ONCE(sk->sk_rcvbuf)) {
166			atomic_inc(&sk->sk_drops);
167			continue;
168		}
169
170		delivered = true;
171		switch (nexthdr) {
172		case IPPROTO_ICMPV6:
173			filtered = icmpv6_filter(sk, skb);
174			break;
175
176#if IS_ENABLED(CONFIG_IPV6_MIP6)
177		case IPPROTO_MH:
178		{
179			/* XXX: To validate MH only once for each packet,
180			 * this is placed here. It should be after checking
181			 * xfrm policy, however it doesn't. The checking xfrm
182			 * policy is placed in rawv6_rcv() because it is
183			 * required for each socket.
184			 */
185			mh_filter_t *filter;
186
187			filter = rcu_dereference(mh_filter);
188			filtered = filter ? (*filter)(sk, skb) : 0;
189			break;
190		}
191#endif
192		default:
193			filtered = 0;
194			break;
195		}
196
197		if (filtered < 0)
198			break;
199		if (filtered == 0) {
200			struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC);
201
202			/* Not releasing hash table! */
203			if (clone)
204				rawv6_rcv(sk, clone);
205		}
206	}
207	rcu_read_unlock();
208	return delivered;
209}
210
211bool raw6_local_deliver(struct sk_buff *skb, int nexthdr)
212{
213	return ipv6_raw_deliver(skb, nexthdr);
214}
215
216/* This cleans up af_inet6 a bit. -DaveM */
217static int rawv6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
218{
219	struct inet_sock *inet = inet_sk(sk);
220	struct ipv6_pinfo *np = inet6_sk(sk);
221	struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
222	__be32 v4addr = 0;
223	int addr_type;
224	int err;
225
226	if (addr_len < SIN6_LEN_RFC2133)
227		return -EINVAL;
228
229	if (addr->sin6_family != AF_INET6)
230		return -EINVAL;
231
232	addr_type = ipv6_addr_type(&addr->sin6_addr);
233
234	/* Raw sockets are IPv6 only */
235	if (addr_type == IPV6_ADDR_MAPPED)
236		return -EADDRNOTAVAIL;
237
238	lock_sock(sk);
239
240	err = -EINVAL;
241	if (sk->sk_state != TCP_CLOSE)
242		goto out;
243
244	rcu_read_lock();
245	/* Check if the address belongs to the host. */
246	if (addr_type != IPV6_ADDR_ANY) {
247		struct net_device *dev = NULL;
248
249		if (__ipv6_addr_needs_scope_id(addr_type)) {
250			if (addr_len >= sizeof(struct sockaddr_in6) &&
251			    addr->sin6_scope_id) {
252				/* Override any existing binding, if another
253				 * one is supplied by user.
254				 */
255				sk->sk_bound_dev_if = addr->sin6_scope_id;
256			}
257
258			/* Binding to link-local address requires an interface */
259			if (!sk->sk_bound_dev_if)
260				goto out_unlock;
261		}
262
263		if (sk->sk_bound_dev_if) {
264			err = -ENODEV;
265			dev = dev_get_by_index_rcu(sock_net(sk),
266						   sk->sk_bound_dev_if);
267			if (!dev)
268				goto out_unlock;
269		}
270
271		/* ipv4 addr of the socket is invalid.  Only the
272		 * unspecified and mapped address have a v4 equivalent.
273		 */
274		v4addr = LOOPBACK4_IPV6;
275		if (!(addr_type & IPV6_ADDR_MULTICAST) &&
276		    !ipv6_can_nonlocal_bind(sock_net(sk), inet)) {
277			err = -EADDRNOTAVAIL;
278			if (!ipv6_chk_addr(sock_net(sk), &addr->sin6_addr,
279					   dev, 0)) {
280				goto out_unlock;
281			}
282		}
283	}
284
285	inet->inet_rcv_saddr = inet->inet_saddr = v4addr;
286	sk->sk_v6_rcv_saddr = addr->sin6_addr;
287	if (!(addr_type & IPV6_ADDR_MULTICAST))
288		np->saddr = addr->sin6_addr;
289	err = 0;
290out_unlock:
291	rcu_read_unlock();
292out:
293	release_sock(sk);
294	return err;
295}
296
297static void rawv6_err(struct sock *sk, struct sk_buff *skb,
298		      u8 type, u8 code, int offset, __be32 info)
299{
300	bool recverr = inet6_test_bit(RECVERR6, sk);
301	struct ipv6_pinfo *np = inet6_sk(sk);
302	int err;
303	int harderr;
304
305	/* Report error on raw socket, if:
306	   1. User requested recverr.
307	   2. Socket is connected (otherwise the error indication
308	      is useless without recverr and error is hard.
309	 */
310	if (!recverr && sk->sk_state != TCP_ESTABLISHED)
311		return;
312
313	harderr = icmpv6_err_convert(type, code, &err);
314	if (type == ICMPV6_PKT_TOOBIG) {
315		ip6_sk_update_pmtu(skb, sk, info);
316		harderr = (READ_ONCE(np->pmtudisc) == IPV6_PMTUDISC_DO);
317	}
318	if (type == NDISC_REDIRECT) {
319		ip6_sk_redirect(skb, sk);
320		return;
321	}
322	if (recverr) {
323		u8 *payload = skb->data;
324		if (!inet_test_bit(HDRINCL, sk))
325			payload += offset;
326		ipv6_icmp_error(sk, skb, err, 0, ntohl(info), payload);
327	}
328
329	if (recverr || harderr) {
330		sk->sk_err = err;
331		sk_error_report(sk);
332	}
333}
334
335void raw6_icmp_error(struct sk_buff *skb, int nexthdr,
336		u8 type, u8 code, int inner_offset, __be32 info)
337{
338	struct net *net = dev_net(skb->dev);
339	struct hlist_head *hlist;
340	struct sock *sk;
341	int hash;
342
343	hash = raw_hashfunc(net, nexthdr);
344	hlist = &raw_v6_hashinfo.ht[hash];
345	rcu_read_lock();
346	sk_for_each_rcu(sk, hlist) {
347		/* Note: ipv6_hdr(skb) != skb->data */
348		const struct ipv6hdr *ip6h = (const struct ipv6hdr *)skb->data;
349
350		if (!raw_v6_match(net, sk, nexthdr, &ip6h->saddr, &ip6h->daddr,
351				  inet6_iif(skb), inet6_iif(skb)))
352			continue;
353		rawv6_err(sk, skb, type, code, inner_offset, info);
354	}
355	rcu_read_unlock();
356}
357
358static inline int rawv6_rcv_skb(struct sock *sk, struct sk_buff *skb)
359{
360	enum skb_drop_reason reason;
361
362	if ((raw6_sk(sk)->checksum || rcu_access_pointer(sk->sk_filter)) &&
363	    skb_checksum_complete(skb)) {
364		atomic_inc(&sk->sk_drops);
365		kfree_skb_reason(skb, SKB_DROP_REASON_SKB_CSUM);
366		return NET_RX_DROP;
367	}
368
369	/* Charge it to the socket. */
370	skb_dst_drop(skb);
371	if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0) {
372		kfree_skb_reason(skb, reason);
373		return NET_RX_DROP;
374	}
375
376	return 0;
377}
378
379/*
380 *	This is next to useless...
381 *	if we demultiplex in network layer we don't need the extra call
382 *	just to queue the skb...
383 *	maybe we could have the network decide upon a hint if it
384 *	should call raw_rcv for demultiplexing
385 */
386int rawv6_rcv(struct sock *sk, struct sk_buff *skb)
387{
388	struct inet_sock *inet = inet_sk(sk);
389	struct raw6_sock *rp = raw6_sk(sk);
390
391	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
392		atomic_inc(&sk->sk_drops);
393		kfree_skb_reason(skb, SKB_DROP_REASON_XFRM_POLICY);
394		return NET_RX_DROP;
395	}
396	nf_reset_ct(skb);
397
398	if (!rp->checksum)
399		skb->ip_summed = CHECKSUM_UNNECESSARY;
400
401	if (skb->ip_summed == CHECKSUM_COMPLETE) {
402		skb_postpull_rcsum(skb, skb_network_header(skb),
403				   skb_network_header_len(skb));
404		if (!csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
405				     &ipv6_hdr(skb)->daddr,
406				     skb->len, inet->inet_num, skb->csum))
407			skb->ip_summed = CHECKSUM_UNNECESSARY;
408	}
409	if (!skb_csum_unnecessary(skb))
410		skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
411							 &ipv6_hdr(skb)->daddr,
412							 skb->len,
413							 inet->inet_num, 0));
414
415	if (inet_test_bit(HDRINCL, sk)) {
416		if (skb_checksum_complete(skb)) {
417			atomic_inc(&sk->sk_drops);
418			kfree_skb_reason(skb, SKB_DROP_REASON_SKB_CSUM);
419			return NET_RX_DROP;
420		}
421	}
422
423	rawv6_rcv_skb(sk, skb);
424	return 0;
425}
426
427
428/*
429 *	This should be easy, if there is something there
430 *	we return it, otherwise we block.
431 */
432
433static int rawv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
434			 int flags, int *addr_len)
435{
436	struct ipv6_pinfo *np = inet6_sk(sk);
437	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
438	struct sk_buff *skb;
439	size_t copied;
440	int err;
441
442	if (flags & MSG_OOB)
443		return -EOPNOTSUPP;
444
445	if (flags & MSG_ERRQUEUE)
446		return ipv6_recv_error(sk, msg, len, addr_len);
447
448	if (np->rxpmtu && np->rxopt.bits.rxpmtu)
449		return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
450
451	skb = skb_recv_datagram(sk, flags, &err);
452	if (!skb)
453		goto out;
454
455	copied = skb->len;
456	if (copied > len) {
457		copied = len;
458		msg->msg_flags |= MSG_TRUNC;
459	}
460
461	if (skb_csum_unnecessary(skb)) {
462		err = skb_copy_datagram_msg(skb, 0, msg, copied);
463	} else if (msg->msg_flags&MSG_TRUNC) {
464		if (__skb_checksum_complete(skb))
465			goto csum_copy_err;
466		err = skb_copy_datagram_msg(skb, 0, msg, copied);
467	} else {
468		err = skb_copy_and_csum_datagram_msg(skb, 0, msg);
469		if (err == -EINVAL)
470			goto csum_copy_err;
471	}
472	if (err)
473		goto out_free;
474
475	/* Copy the address. */
476	if (sin6) {
477		sin6->sin6_family = AF_INET6;
478		sin6->sin6_port = 0;
479		sin6->sin6_addr = ipv6_hdr(skb)->saddr;
480		sin6->sin6_flowinfo = 0;
481		sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr,
482							  inet6_iif(skb));
483		*addr_len = sizeof(*sin6);
484	}
485
486	sock_recv_cmsgs(msg, sk, skb);
487
488	if (np->rxopt.all)
489		ip6_datagram_recv_ctl(sk, msg, skb);
490
491	err = copied;
492	if (flags & MSG_TRUNC)
493		err = skb->len;
494
495out_free:
496	skb_free_datagram(sk, skb);
497out:
498	return err;
499
500csum_copy_err:
501	skb_kill_datagram(sk, skb, flags);
502
503	/* Error for blocking case is chosen to masquerade
504	   as some normal condition.
505	 */
506	err = (flags&MSG_DONTWAIT) ? -EAGAIN : -EHOSTUNREACH;
507	goto out;
508}
509
510static int rawv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
511				     struct raw6_sock *rp)
512{
513	struct ipv6_txoptions *opt;
514	struct sk_buff *skb;
515	int err = 0;
516	int offset;
517	int len;
518	int total_len;
519	__wsum tmp_csum;
520	__sum16 csum;
521
522	if (!rp->checksum)
523		goto send;
524
525	skb = skb_peek(&sk->sk_write_queue);
526	if (!skb)
527		goto out;
528
529	offset = rp->offset;
530	total_len = inet_sk(sk)->cork.base.length;
531	opt = inet6_sk(sk)->cork.opt;
532	total_len -= opt ? opt->opt_flen : 0;
533
534	if (offset >= total_len - 1) {
535		err = -EINVAL;
536		ip6_flush_pending_frames(sk);
537		goto out;
538	}
539
540	/* should be check HW csum miyazawa */
541	if (skb_queue_len(&sk->sk_write_queue) == 1) {
542		/*
543		 * Only one fragment on the socket.
544		 */
545		tmp_csum = skb->csum;
546	} else {
547		struct sk_buff *csum_skb = NULL;
548		tmp_csum = 0;
549
550		skb_queue_walk(&sk->sk_write_queue, skb) {
551			tmp_csum = csum_add(tmp_csum, skb->csum);
552
553			if (csum_skb)
554				continue;
555
556			len = skb->len - skb_transport_offset(skb);
557			if (offset >= len) {
558				offset -= len;
559				continue;
560			}
561
562			csum_skb = skb;
563		}
564
565		skb = csum_skb;
566	}
567
568	offset += skb_transport_offset(skb);
569	err = skb_copy_bits(skb, offset, &csum, 2);
570	if (err < 0) {
571		ip6_flush_pending_frames(sk);
572		goto out;
573	}
574
575	/* in case cksum was not initialized */
576	if (unlikely(csum))
577		tmp_csum = csum_sub(tmp_csum, csum_unfold(csum));
578
579	csum = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
580			       total_len, fl6->flowi6_proto, tmp_csum);
581
582	if (csum == 0 && fl6->flowi6_proto == IPPROTO_UDP)
583		csum = CSUM_MANGLED_0;
584
585	BUG_ON(skb_store_bits(skb, offset, &csum, 2));
586
587send:
588	err = ip6_push_pending_frames(sk);
589out:
590	return err;
591}
592
593static int rawv6_send_hdrinc(struct sock *sk, struct msghdr *msg, int length,
594			struct flowi6 *fl6, struct dst_entry **dstp,
595			unsigned int flags, const struct sockcm_cookie *sockc)
596{
597	struct net *net = sock_net(sk);
598	struct ipv6hdr *iph;
599	struct sk_buff *skb;
600	int err;
601	struct rt6_info *rt = (struct rt6_info *)*dstp;
602	int hlen = LL_RESERVED_SPACE(rt->dst.dev);
603	int tlen = rt->dst.dev->needed_tailroom;
604
605	if (length > rt->dst.dev->mtu) {
606		ipv6_local_error(sk, EMSGSIZE, fl6, rt->dst.dev->mtu);
607		return -EMSGSIZE;
608	}
609	if (length < sizeof(struct ipv6hdr))
610		return -EINVAL;
611	if (flags&MSG_PROBE)
612		goto out;
613
614	skb = sock_alloc_send_skb(sk,
615				  length + hlen + tlen + 15,
616				  flags & MSG_DONTWAIT, &err);
617	if (!skb)
618		goto error;
619	skb_reserve(skb, hlen);
620
621	skb->protocol = htons(ETH_P_IPV6);
622	skb->priority = READ_ONCE(sk->sk_priority);
623	skb->mark = sockc->mark;
624	skb->tstamp = sockc->transmit_time;
625
626	skb_put(skb, length);
627	skb_reset_network_header(skb);
628	iph = ipv6_hdr(skb);
629
630	skb->ip_summed = CHECKSUM_NONE;
631
632	skb_setup_tx_timestamp(skb, sockc->tsflags);
633
634	if (flags & MSG_CONFIRM)
635		skb_set_dst_pending_confirm(skb, 1);
636
637	skb->transport_header = skb->network_header;
638	err = memcpy_from_msg(iph, msg, length);
639	if (err) {
640		err = -EFAULT;
641		kfree_skb(skb);
642		goto error;
643	}
644
645	skb_dst_set(skb, &rt->dst);
646	*dstp = NULL;
647
648	/* if egress device is enslaved to an L3 master device pass the
649	 * skb to its handler for processing
650	 */
651	skb = l3mdev_ip6_out(sk, skb);
652	if (unlikely(!skb))
653		return 0;
654
655	/* Acquire rcu_read_lock() in case we need to use rt->rt6i_idev
656	 * in the error path. Since skb has been freed, the dst could
657	 * have been queued for deletion.
658	 */
659	rcu_read_lock();
660	IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTREQUESTS);
661	err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk, skb,
662		      NULL, rt->dst.dev, dst_output);
663	if (err > 0)
664		err = net_xmit_errno(err);
665	if (err) {
666		IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
667		rcu_read_unlock();
668		goto error_check;
669	}
670	rcu_read_unlock();
671out:
672	return 0;
673
674error:
675	IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
676error_check:
677	if (err == -ENOBUFS && !inet6_test_bit(RECVERR6, sk))
678		err = 0;
679	return err;
680}
681
682struct raw6_frag_vec {
683	struct msghdr *msg;
684	int hlen;
685	char c[4];
686};
687
688static int rawv6_probe_proto_opt(struct raw6_frag_vec *rfv, struct flowi6 *fl6)
689{
690	int err = 0;
691	switch (fl6->flowi6_proto) {
692	case IPPROTO_ICMPV6:
693		rfv->hlen = 2;
694		err = memcpy_from_msg(rfv->c, rfv->msg, rfv->hlen);
695		if (!err) {
696			fl6->fl6_icmp_type = rfv->c[0];
697			fl6->fl6_icmp_code = rfv->c[1];
698		}
699		break;
700	case IPPROTO_MH:
701		rfv->hlen = 4;
702		err = memcpy_from_msg(rfv->c, rfv->msg, rfv->hlen);
703		if (!err)
704			fl6->fl6_mh_type = rfv->c[2];
705	}
706	return err;
707}
708
709static int raw6_getfrag(void *from, char *to, int offset, int len, int odd,
710		       struct sk_buff *skb)
711{
712	struct raw6_frag_vec *rfv = from;
713
714	if (offset < rfv->hlen) {
715		int copy = min(rfv->hlen - offset, len);
716
717		if (skb->ip_summed == CHECKSUM_PARTIAL)
718			memcpy(to, rfv->c + offset, copy);
719		else
720			skb->csum = csum_block_add(
721				skb->csum,
722				csum_partial_copy_nocheck(rfv->c + offset,
723							  to, copy),
724				odd);
725
726		odd = 0;
727		offset += copy;
728		to += copy;
729		len -= copy;
730
731		if (!len)
732			return 0;
733	}
734
735	offset -= rfv->hlen;
736
737	return ip_generic_getfrag(rfv->msg, to, offset, len, odd, skb);
738}
739
740static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
741{
742	struct ipv6_txoptions *opt_to_free = NULL;
743	struct ipv6_txoptions opt_space;
744	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
745	struct in6_addr *daddr, *final_p, final;
746	struct inet_sock *inet = inet_sk(sk);
747	struct ipv6_pinfo *np = inet6_sk(sk);
748	struct raw6_sock *rp = raw6_sk(sk);
749	struct ipv6_txoptions *opt = NULL;
750	struct ip6_flowlabel *flowlabel = NULL;
751	struct dst_entry *dst = NULL;
752	struct raw6_frag_vec rfv;
753	struct flowi6 fl6;
754	struct ipcm6_cookie ipc6;
755	int addr_len = msg->msg_namelen;
756	int hdrincl;
757	u16 proto;
758	int err;
759
760	/* Rough check on arithmetic overflow,
761	   better check is made in ip6_append_data().
762	 */
763	if (len > INT_MAX)
764		return -EMSGSIZE;
765
766	/* Mirror BSD error message compatibility */
767	if (msg->msg_flags & MSG_OOB)
768		return -EOPNOTSUPP;
769
770	hdrincl = inet_test_bit(HDRINCL, sk);
771
772	/*
773	 *	Get and verify the address.
774	 */
775	memset(&fl6, 0, sizeof(fl6));
776
777	fl6.flowi6_mark = READ_ONCE(sk->sk_mark);
778	fl6.flowi6_uid = sk->sk_uid;
779
780	ipcm6_init(&ipc6);
781	ipc6.sockc.tsflags = READ_ONCE(sk->sk_tsflags);
782	ipc6.sockc.mark = fl6.flowi6_mark;
783
784	if (sin6) {
785		if (addr_len < SIN6_LEN_RFC2133)
786			return -EINVAL;
787
788		if (sin6->sin6_family && sin6->sin6_family != AF_INET6)
789			return -EAFNOSUPPORT;
790
791		/* port is the proto value [0..255] carried in nexthdr */
792		proto = ntohs(sin6->sin6_port);
793
794		if (!proto)
795			proto = inet->inet_num;
796		else if (proto != inet->inet_num &&
797			 inet->inet_num != IPPROTO_RAW)
798			return -EINVAL;
799
800		if (proto > 255)
801			return -EINVAL;
802
803		daddr = &sin6->sin6_addr;
804		if (inet6_test_bit(SNDFLOW, sk)) {
805			fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
806			if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
807				flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
808				if (IS_ERR(flowlabel))
809					return -EINVAL;
810			}
811		}
812
813		/*
814		 * Otherwise it will be difficult to maintain
815		 * sk->sk_dst_cache.
816		 */
817		if (sk->sk_state == TCP_ESTABLISHED &&
818		    ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
819			daddr = &sk->sk_v6_daddr;
820
821		if (addr_len >= sizeof(struct sockaddr_in6) &&
822		    sin6->sin6_scope_id &&
823		    __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
824			fl6.flowi6_oif = sin6->sin6_scope_id;
825	} else {
826		if (sk->sk_state != TCP_ESTABLISHED)
827			return -EDESTADDRREQ;
828
829		proto = inet->inet_num;
830		daddr = &sk->sk_v6_daddr;
831		fl6.flowlabel = np->flow_label;
832	}
833
834	if (fl6.flowi6_oif == 0)
835		fl6.flowi6_oif = sk->sk_bound_dev_if;
836
837	if (msg->msg_controllen) {
838		opt = &opt_space;
839		memset(opt, 0, sizeof(struct ipv6_txoptions));
840		opt->tot_len = sizeof(struct ipv6_txoptions);
841		ipc6.opt = opt;
842
843		err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6);
844		if (err < 0) {
845			fl6_sock_release(flowlabel);
846			return err;
847		}
848		if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
849			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
850			if (IS_ERR(flowlabel))
851				return -EINVAL;
852		}
853		if (!(opt->opt_nflen|opt->opt_flen))
854			opt = NULL;
855	}
856	if (!opt) {
857		opt = txopt_get(np);
858		opt_to_free = opt;
859	}
860	if (flowlabel)
861		opt = fl6_merge_options(&opt_space, flowlabel, opt);
862	opt = ipv6_fixup_options(&opt_space, opt);
863
864	fl6.flowi6_proto = proto;
865	fl6.flowi6_mark = ipc6.sockc.mark;
866
867	if (!hdrincl) {
868		rfv.msg = msg;
869		rfv.hlen = 0;
870		err = rawv6_probe_proto_opt(&rfv, &fl6);
871		if (err)
872			goto out;
873	}
874
875	if (!ipv6_addr_any(daddr))
876		fl6.daddr = *daddr;
877	else
878		fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
879	if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
880		fl6.saddr = np->saddr;
881
882	final_p = fl6_update_dst(&fl6, opt, &final);
883
884	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
885		fl6.flowi6_oif = READ_ONCE(np->mcast_oif);
886	else if (!fl6.flowi6_oif)
887		fl6.flowi6_oif = READ_ONCE(np->ucast_oif);
888	security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
889
890	if (hdrincl)
891		fl6.flowi6_flags |= FLOWI_FLAG_KNOWN_NH;
892
893	if (ipc6.tclass < 0)
894		ipc6.tclass = np->tclass;
895
896	fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
897
898	dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
899	if (IS_ERR(dst)) {
900		err = PTR_ERR(dst);
901		goto out;
902	}
903	if (ipc6.hlimit < 0)
904		ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
905
906	if (ipc6.dontfrag < 0)
907		ipc6.dontfrag = inet6_test_bit(DONTFRAG, sk);
908
909	if (msg->msg_flags&MSG_CONFIRM)
910		goto do_confirm;
911
912back_from_confirm:
913	if (hdrincl)
914		err = rawv6_send_hdrinc(sk, msg, len, &fl6, &dst,
915					msg->msg_flags, &ipc6.sockc);
916	else {
917		ipc6.opt = opt;
918		lock_sock(sk);
919		err = ip6_append_data(sk, raw6_getfrag, &rfv,
920			len, 0, &ipc6, &fl6, (struct rt6_info *)dst,
921			msg->msg_flags);
922
923		if (err)
924			ip6_flush_pending_frames(sk);
925		else if (!(msg->msg_flags & MSG_MORE))
926			err = rawv6_push_pending_frames(sk, &fl6, rp);
927		release_sock(sk);
928	}
929done:
930	dst_release(dst);
931out:
932	fl6_sock_release(flowlabel);
933	txopt_put(opt_to_free);
934	return err < 0 ? err : len;
935do_confirm:
936	if (msg->msg_flags & MSG_PROBE)
937		dst_confirm_neigh(dst, &fl6.daddr);
938	if (!(msg->msg_flags & MSG_PROBE) || len)
939		goto back_from_confirm;
940	err = 0;
941	goto done;
942}
943
944static int rawv6_seticmpfilter(struct sock *sk, int optname,
945			       sockptr_t optval, int optlen)
946{
947	switch (optname) {
948	case ICMPV6_FILTER:
949		if (optlen > sizeof(struct icmp6_filter))
950			optlen = sizeof(struct icmp6_filter);
951		if (copy_from_sockptr(&raw6_sk(sk)->filter, optval, optlen))
952			return -EFAULT;
953		return 0;
954	default:
955		return -ENOPROTOOPT;
956	}
957
958	return 0;
959}
960
961static int rawv6_geticmpfilter(struct sock *sk, int optname,
962			       char __user *optval, int __user *optlen)
963{
964	int len;
965
966	switch (optname) {
967	case ICMPV6_FILTER:
968		if (get_user(len, optlen))
969			return -EFAULT;
970		if (len < 0)
971			return -EINVAL;
972		if (len > sizeof(struct icmp6_filter))
973			len = sizeof(struct icmp6_filter);
974		if (put_user(len, optlen))
975			return -EFAULT;
976		if (copy_to_user(optval, &raw6_sk(sk)->filter, len))
977			return -EFAULT;
978		return 0;
979	default:
980		return -ENOPROTOOPT;
981	}
982
983	return 0;
984}
985
986
987static int do_rawv6_setsockopt(struct sock *sk, int level, int optname,
988			       sockptr_t optval, unsigned int optlen)
989{
990	struct raw6_sock *rp = raw6_sk(sk);
991	int val;
992
993	if (optlen < sizeof(val))
994		return -EINVAL;
995
996	if (copy_from_sockptr(&val, optval, sizeof(val)))
997		return -EFAULT;
998
999	switch (optname) {
1000	case IPV6_HDRINCL:
1001		if (sk->sk_type != SOCK_RAW)
1002			return -EINVAL;
1003		inet_assign_bit(HDRINCL, sk, val);
1004		return 0;
1005	case IPV6_CHECKSUM:
1006		if (inet_sk(sk)->inet_num == IPPROTO_ICMPV6 &&
1007		    level == IPPROTO_IPV6) {
1008			/*
1009			 * RFC3542 tells that IPV6_CHECKSUM socket
1010			 * option in the IPPROTO_IPV6 level is not
1011			 * allowed on ICMPv6 sockets.
1012			 * If you want to set it, use IPPROTO_RAW
1013			 * level IPV6_CHECKSUM socket option
1014			 * (Linux extension).
1015			 */
1016			return -EINVAL;
1017		}
1018
1019		/* You may get strange result with a positive odd offset;
1020		   RFC2292bis agrees with me. */
1021		if (val > 0 && (val&1))
1022			return -EINVAL;
1023		if (val < 0) {
1024			rp->checksum = 0;
1025		} else {
1026			rp->checksum = 1;
1027			rp->offset = val;
1028		}
1029
1030		return 0;
1031
1032	default:
1033		return -ENOPROTOOPT;
1034	}
1035}
1036
1037static int rawv6_setsockopt(struct sock *sk, int level, int optname,
1038			    sockptr_t optval, unsigned int optlen)
1039{
1040	switch (level) {
1041	case SOL_RAW:
1042		break;
1043
1044	case SOL_ICMPV6:
1045		if (inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
1046			return -EOPNOTSUPP;
1047		return rawv6_seticmpfilter(sk, optname, optval, optlen);
1048	case SOL_IPV6:
1049		if (optname == IPV6_CHECKSUM ||
1050		    optname == IPV6_HDRINCL)
1051			break;
1052		fallthrough;
1053	default:
1054		return ipv6_setsockopt(sk, level, optname, optval, optlen);
1055	}
1056
1057	return do_rawv6_setsockopt(sk, level, optname, optval, optlen);
1058}
1059
1060static int do_rawv6_getsockopt(struct sock *sk, int level, int optname,
1061			    char __user *optval, int __user *optlen)
1062{
1063	struct raw6_sock *rp = raw6_sk(sk);
1064	int val, len;
1065
1066	if (get_user(len, optlen))
1067		return -EFAULT;
1068
1069	switch (optname) {
1070	case IPV6_HDRINCL:
1071		val = inet_test_bit(HDRINCL, sk);
1072		break;
1073	case IPV6_CHECKSUM:
1074		/*
1075		 * We allow getsockopt() for IPPROTO_IPV6-level
1076		 * IPV6_CHECKSUM socket option on ICMPv6 sockets
1077		 * since RFC3542 is silent about it.
1078		 */
1079		if (rp->checksum == 0)
1080			val = -1;
1081		else
1082			val = rp->offset;
1083		break;
1084
1085	default:
1086		return -ENOPROTOOPT;
1087	}
1088
1089	len = min_t(unsigned int, sizeof(int), len);
1090
1091	if (put_user(len, optlen))
1092		return -EFAULT;
1093	if (copy_to_user(optval, &val, len))
1094		return -EFAULT;
1095	return 0;
1096}
1097
1098static int rawv6_getsockopt(struct sock *sk, int level, int optname,
1099			  char __user *optval, int __user *optlen)
1100{
1101	switch (level) {
1102	case SOL_RAW:
1103		break;
1104
1105	case SOL_ICMPV6:
1106		if (inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
1107			return -EOPNOTSUPP;
1108		return rawv6_geticmpfilter(sk, optname, optval, optlen);
1109	case SOL_IPV6:
1110		if (optname == IPV6_CHECKSUM ||
1111		    optname == IPV6_HDRINCL)
1112			break;
1113		fallthrough;
1114	default:
1115		return ipv6_getsockopt(sk, level, optname, optval, optlen);
1116	}
1117
1118	return do_rawv6_getsockopt(sk, level, optname, optval, optlen);
1119}
1120
1121static int rawv6_ioctl(struct sock *sk, int cmd, int *karg)
1122{
1123	switch (cmd) {
1124	case SIOCOUTQ: {
1125		*karg = sk_wmem_alloc_get(sk);
1126		return 0;
1127	}
1128	case SIOCINQ: {
1129		struct sk_buff *skb;
1130
1131		spin_lock_bh(&sk->sk_receive_queue.lock);
1132		skb = skb_peek(&sk->sk_receive_queue);
1133		if (skb)
1134			*karg = skb->len;
1135		else
1136			*karg = 0;
1137		spin_unlock_bh(&sk->sk_receive_queue.lock);
1138		return 0;
1139	}
1140
1141	default:
1142#ifdef CONFIG_IPV6_MROUTE
1143		return ip6mr_ioctl(sk, cmd, karg);
1144#else
1145		return -ENOIOCTLCMD;
1146#endif
1147	}
1148}
1149
1150#ifdef CONFIG_COMPAT
1151static int compat_rawv6_ioctl(struct sock *sk, unsigned int cmd, unsigned long arg)
1152{
1153	switch (cmd) {
1154	case SIOCOUTQ:
1155	case SIOCINQ:
1156		return -ENOIOCTLCMD;
1157	default:
1158#ifdef CONFIG_IPV6_MROUTE
1159		return ip6mr_compat_ioctl(sk, cmd, compat_ptr(arg));
1160#else
1161		return -ENOIOCTLCMD;
1162#endif
1163	}
1164}
1165#endif
1166
1167static void rawv6_close(struct sock *sk, long timeout)
1168{
1169	if (inet_sk(sk)->inet_num == IPPROTO_RAW)
1170		ip6_ra_control(sk, -1);
1171	ip6mr_sk_done(sk);
1172	sk_common_release(sk);
1173}
1174
1175static void raw6_destroy(struct sock *sk)
1176{
1177	lock_sock(sk);
1178	ip6_flush_pending_frames(sk);
1179	release_sock(sk);
1180}
1181
1182static int rawv6_init_sk(struct sock *sk)
1183{
1184	struct raw6_sock *rp = raw6_sk(sk);
1185
1186	switch (inet_sk(sk)->inet_num) {
1187	case IPPROTO_ICMPV6:
1188		rp->checksum = 1;
1189		rp->offset   = 2;
1190		break;
1191	case IPPROTO_MH:
1192		rp->checksum = 1;
1193		rp->offset   = 4;
1194		break;
1195	default:
1196		break;
1197	}
1198	return 0;
1199}
1200
1201struct proto rawv6_prot = {
1202	.name		   = "RAWv6",
1203	.owner		   = THIS_MODULE,
1204	.close		   = rawv6_close,
1205	.destroy	   = raw6_destroy,
1206	.connect	   = ip6_datagram_connect_v6_only,
1207	.disconnect	   = __udp_disconnect,
1208	.ioctl		   = rawv6_ioctl,
1209	.init		   = rawv6_init_sk,
1210	.setsockopt	   = rawv6_setsockopt,
1211	.getsockopt	   = rawv6_getsockopt,
1212	.sendmsg	   = rawv6_sendmsg,
1213	.recvmsg	   = rawv6_recvmsg,
1214	.bind		   = rawv6_bind,
1215	.backlog_rcv	   = rawv6_rcv_skb,
1216	.hash		   = raw_hash_sk,
1217	.unhash		   = raw_unhash_sk,
1218	.obj_size	   = sizeof(struct raw6_sock),
1219	.ipv6_pinfo_offset = offsetof(struct raw6_sock, inet6),
1220	.useroffset	   = offsetof(struct raw6_sock, filter),
1221	.usersize	   = sizeof_field(struct raw6_sock, filter),
1222	.h.raw_hash	   = &raw_v6_hashinfo,
1223#ifdef CONFIG_COMPAT
1224	.compat_ioctl	   = compat_rawv6_ioctl,
1225#endif
1226	.diag_destroy	   = raw_abort,
1227};
1228
1229#ifdef CONFIG_PROC_FS
1230static int raw6_seq_show(struct seq_file *seq, void *v)
1231{
1232	if (v == SEQ_START_TOKEN) {
1233		seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1234	} else {
1235		struct sock *sp = v;
1236		__u16 srcp  = inet_sk(sp)->inet_num;
1237		ip6_dgram_sock_seq_show(seq, v, srcp, 0,
1238					raw_seq_private(seq)->bucket);
1239	}
1240	return 0;
1241}
1242
1243static const struct seq_operations raw6_seq_ops = {
1244	.start =	raw_seq_start,
1245	.next =		raw_seq_next,
1246	.stop =		raw_seq_stop,
1247	.show =		raw6_seq_show,
1248};
1249
1250static int __net_init raw6_init_net(struct net *net)
1251{
1252	if (!proc_create_net_data("raw6", 0444, net->proc_net, &raw6_seq_ops,
1253			sizeof(struct raw_iter_state), &raw_v6_hashinfo))
1254		return -ENOMEM;
1255
1256	return 0;
1257}
1258
1259static void __net_exit raw6_exit_net(struct net *net)
1260{
1261	remove_proc_entry("raw6", net->proc_net);
1262}
1263
1264static struct pernet_operations raw6_net_ops = {
1265	.init = raw6_init_net,
1266	.exit = raw6_exit_net,
1267};
1268
1269int __init raw6_proc_init(void)
1270{
1271	return register_pernet_subsys(&raw6_net_ops);
1272}
1273
1274void raw6_proc_exit(void)
1275{
1276	unregister_pernet_subsys(&raw6_net_ops);
1277}
1278#endif	/* CONFIG_PROC_FS */
1279
1280/* Same as inet6_dgram_ops, sans udp_poll.  */
1281const struct proto_ops inet6_sockraw_ops = {
1282	.family		   = PF_INET6,
1283	.owner		   = THIS_MODULE,
1284	.release	   = inet6_release,
1285	.bind		   = inet6_bind,
1286	.connect	   = inet_dgram_connect,	/* ok		*/
1287	.socketpair	   = sock_no_socketpair,	/* a do nothing	*/
1288	.accept		   = sock_no_accept,		/* a do nothing	*/
1289	.getname	   = inet6_getname,
1290	.poll		   = datagram_poll,		/* ok		*/
1291	.ioctl		   = inet6_ioctl,		/* must change  */
1292	.gettstamp	   = sock_gettstamp,
1293	.listen		   = sock_no_listen,		/* ok		*/
1294	.shutdown	   = inet_shutdown,		/* ok		*/
1295	.setsockopt	   = sock_common_setsockopt,	/* ok		*/
1296	.getsockopt	   = sock_common_getsockopt,	/* ok		*/
1297	.sendmsg	   = inet_sendmsg,		/* ok		*/
1298	.recvmsg	   = sock_common_recvmsg,	/* ok		*/
1299	.mmap		   = sock_no_mmap,
1300#ifdef CONFIG_COMPAT
1301	.compat_ioctl	   = inet6_compat_ioctl,
1302#endif
1303};
1304
1305static struct inet_protosw rawv6_protosw = {
1306	.type		= SOCK_RAW,
1307	.protocol	= IPPROTO_IP,	/* wild card */
1308	.prot		= &rawv6_prot,
1309	.ops		= &inet6_sockraw_ops,
1310	.flags		= INET_PROTOSW_REUSE,
1311};
1312
1313int __init rawv6_init(void)
1314{
1315	return inet6_register_protosw(&rawv6_protosw);
1316}
1317
1318void rawv6_exit(void)
1319{
1320	inet6_unregister_protosw(&rawv6_protosw);
1321}
1322