Linux Audio

Check our new training course

Buildroot integration, development and maintenance

Need a Buildroot system for your embedded project?
Loading...
v6.8
   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	bool recverr = inet6_test_bit(RECVERR6, sk);
 295	struct ipv6_pinfo *np = inet6_sk(sk);
 296	int err;
 297	int harderr;
 298
 299	/* Report error on raw socket, if:
 300	   1. User requested recverr.
 301	   2. Socket is connected (otherwise the error indication
 302	      is useless without recverr and error is hard.
 303	 */
 304	if (!recverr && sk->sk_state != TCP_ESTABLISHED)
 305		return;
 306
 307	harderr = icmpv6_err_convert(type, code, &err);
 308	if (type == ICMPV6_PKT_TOOBIG) {
 309		ip6_sk_update_pmtu(skb, sk, info);
 310		harderr = (READ_ONCE(np->pmtudisc) == IPV6_PMTUDISC_DO);
 311	}
 312	if (type == NDISC_REDIRECT) {
 313		ip6_sk_redirect(skb, sk);
 314		return;
 315	}
 316	if (recverr) {
 317		u8 *payload = skb->data;
 318		if (!inet_test_bit(HDRINCL, sk))
 319			payload += offset;
 320		ipv6_icmp_error(sk, skb, err, 0, ntohl(info), payload);
 321	}
 322
 323	if (recverr || harderr) {
 324		sk->sk_err = err;
 325		sk_error_report(sk);
 326	}
 327}
 328
 329void raw6_icmp_error(struct sk_buff *skb, int nexthdr,
 330		u8 type, u8 code, int inner_offset, __be32 info)
 331{
 332	struct net *net = dev_net(skb->dev);
 333	struct hlist_head *hlist;
 334	struct sock *sk;
 335	int hash;
 336
 337	hash = raw_hashfunc(net, nexthdr);
 338	hlist = &raw_v6_hashinfo.ht[hash];
 339	rcu_read_lock();
 340	sk_for_each_rcu(sk, hlist) {
 341		/* Note: ipv6_hdr(skb) != skb->data */
 342		const struct ipv6hdr *ip6h = (const struct ipv6hdr *)skb->data;
 343
 344		if (!raw_v6_match(net, sk, nexthdr, &ip6h->saddr, &ip6h->daddr,
 345				  inet6_iif(skb), inet6_iif(skb)))
 346			continue;
 347		rawv6_err(sk, skb, NULL, type, code, inner_offset, info);
 348	}
 349	rcu_read_unlock();
 350}
 351
 352static inline int rawv6_rcv_skb(struct sock *sk, struct sk_buff *skb)
 353{
 354	enum skb_drop_reason reason;
 355
 356	if ((raw6_sk(sk)->checksum || rcu_access_pointer(sk->sk_filter)) &&
 357	    skb_checksum_complete(skb)) {
 358		atomic_inc(&sk->sk_drops);
 359		kfree_skb_reason(skb, SKB_DROP_REASON_SKB_CSUM);
 360		return NET_RX_DROP;
 361	}
 362
 363	/* Charge it to the socket. */
 364	skb_dst_drop(skb);
 365	if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0) {
 366		kfree_skb_reason(skb, reason);
 367		return NET_RX_DROP;
 368	}
 369
 370	return 0;
 371}
 372
 373/*
 374 *	This is next to useless...
 375 *	if we demultiplex in network layer we don't need the extra call
 376 *	just to queue the skb...
 377 *	maybe we could have the network decide upon a hint if it
 378 *	should call raw_rcv for demultiplexing
 379 */
 380int rawv6_rcv(struct sock *sk, struct sk_buff *skb)
 381{
 382	struct inet_sock *inet = inet_sk(sk);
 383	struct raw6_sock *rp = raw6_sk(sk);
 384
 385	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
 386		atomic_inc(&sk->sk_drops);
 387		kfree_skb_reason(skb, SKB_DROP_REASON_XFRM_POLICY);
 388		return NET_RX_DROP;
 389	}
 390	nf_reset_ct(skb);
 391
 392	if (!rp->checksum)
 393		skb->ip_summed = CHECKSUM_UNNECESSARY;
 394
 395	if (skb->ip_summed == CHECKSUM_COMPLETE) {
 396		skb_postpull_rcsum(skb, skb_network_header(skb),
 397				   skb_network_header_len(skb));
 398		if (!csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
 399				     &ipv6_hdr(skb)->daddr,
 400				     skb->len, inet->inet_num, skb->csum))
 401			skb->ip_summed = CHECKSUM_UNNECESSARY;
 402	}
 403	if (!skb_csum_unnecessary(skb))
 404		skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
 405							 &ipv6_hdr(skb)->daddr,
 406							 skb->len,
 407							 inet->inet_num, 0));
 408
 409	if (inet_test_bit(HDRINCL, sk)) {
 410		if (skb_checksum_complete(skb)) {
 411			atomic_inc(&sk->sk_drops);
 412			kfree_skb_reason(skb, SKB_DROP_REASON_SKB_CSUM);
 413			return NET_RX_DROP;
 414		}
 415	}
 416
 417	rawv6_rcv_skb(sk, skb);
 418	return 0;
 419}
 420
 421
 422/*
 423 *	This should be easy, if there is something there
 424 *	we return it, otherwise we block.
 425 */
 426
 427static int rawv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 428			 int flags, int *addr_len)
 429{
 430	struct ipv6_pinfo *np = inet6_sk(sk);
 431	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
 432	struct sk_buff *skb;
 433	size_t copied;
 434	int err;
 435
 436	if (flags & MSG_OOB)
 437		return -EOPNOTSUPP;
 438
 439	if (flags & MSG_ERRQUEUE)
 440		return ipv6_recv_error(sk, msg, len, addr_len);
 441
 442	if (np->rxpmtu && np->rxopt.bits.rxpmtu)
 443		return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
 444
 445	skb = skb_recv_datagram(sk, flags, &err);
 446	if (!skb)
 447		goto out;
 448
 449	copied = skb->len;
 450	if (copied > len) {
 451		copied = len;
 452		msg->msg_flags |= MSG_TRUNC;
 453	}
 454
 455	if (skb_csum_unnecessary(skb)) {
 456		err = skb_copy_datagram_msg(skb, 0, msg, copied);
 457	} else if (msg->msg_flags&MSG_TRUNC) {
 458		if (__skb_checksum_complete(skb))
 459			goto csum_copy_err;
 460		err = skb_copy_datagram_msg(skb, 0, msg, copied);
 461	} else {
 462		err = skb_copy_and_csum_datagram_msg(skb, 0, msg);
 463		if (err == -EINVAL)
 464			goto csum_copy_err;
 465	}
 466	if (err)
 467		goto out_free;
 468
 469	/* Copy the address. */
 470	if (sin6) {
 471		sin6->sin6_family = AF_INET6;
 472		sin6->sin6_port = 0;
 473		sin6->sin6_addr = ipv6_hdr(skb)->saddr;
 474		sin6->sin6_flowinfo = 0;
 475		sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr,
 476							  inet6_iif(skb));
 477		*addr_len = sizeof(*sin6);
 478	}
 479
 480	sock_recv_cmsgs(msg, sk, skb);
 481
 482	if (np->rxopt.all)
 483		ip6_datagram_recv_ctl(sk, msg, skb);
 484
 485	err = copied;
 486	if (flags & MSG_TRUNC)
 487		err = skb->len;
 488
 489out_free:
 490	skb_free_datagram(sk, skb);
 491out:
 492	return err;
 493
 494csum_copy_err:
 495	skb_kill_datagram(sk, skb, flags);
 496
 497	/* Error for blocking case is chosen to masquerade
 498	   as some normal condition.
 499	 */
 500	err = (flags&MSG_DONTWAIT) ? -EAGAIN : -EHOSTUNREACH;
 501	goto out;
 502}
 503
 504static int rawv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
 505				     struct raw6_sock *rp)
 506{
 507	struct ipv6_txoptions *opt;
 508	struct sk_buff *skb;
 509	int err = 0;
 510	int offset;
 511	int len;
 512	int total_len;
 513	__wsum tmp_csum;
 514	__sum16 csum;
 515
 516	if (!rp->checksum)
 517		goto send;
 518
 519	skb = skb_peek(&sk->sk_write_queue);
 520	if (!skb)
 521		goto out;
 522
 523	offset = rp->offset;
 524	total_len = inet_sk(sk)->cork.base.length;
 525	opt = inet6_sk(sk)->cork.opt;
 526	total_len -= opt ? opt->opt_flen : 0;
 527
 528	if (offset >= total_len - 1) {
 529		err = -EINVAL;
 530		ip6_flush_pending_frames(sk);
 531		goto out;
 532	}
 533
 534	/* should be check HW csum miyazawa */
 535	if (skb_queue_len(&sk->sk_write_queue) == 1) {
 536		/*
 537		 * Only one fragment on the socket.
 538		 */
 539		tmp_csum = skb->csum;
 540	} else {
 541		struct sk_buff *csum_skb = NULL;
 542		tmp_csum = 0;
 543
 544		skb_queue_walk(&sk->sk_write_queue, skb) {
 545			tmp_csum = csum_add(tmp_csum, skb->csum);
 546
 547			if (csum_skb)
 548				continue;
 549
 550			len = skb->len - skb_transport_offset(skb);
 551			if (offset >= len) {
 552				offset -= len;
 553				continue;
 554			}
 555
 556			csum_skb = skb;
 557		}
 558
 559		skb = csum_skb;
 560	}
 561
 562	offset += skb_transport_offset(skb);
 563	err = skb_copy_bits(skb, offset, &csum, 2);
 564	if (err < 0) {
 565		ip6_flush_pending_frames(sk);
 566		goto out;
 567	}
 568
 569	/* in case cksum was not initialized */
 570	if (unlikely(csum))
 571		tmp_csum = csum_sub(tmp_csum, csum_unfold(csum));
 572
 573	csum = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
 574			       total_len, fl6->flowi6_proto, tmp_csum);
 575
 576	if (csum == 0 && fl6->flowi6_proto == IPPROTO_UDP)
 577		csum = CSUM_MANGLED_0;
 578
 579	BUG_ON(skb_store_bits(skb, offset, &csum, 2));
 580
 581send:
 582	err = ip6_push_pending_frames(sk);
 583out:
 584	return err;
 585}
 586
 587static int rawv6_send_hdrinc(struct sock *sk, struct msghdr *msg, int length,
 588			struct flowi6 *fl6, struct dst_entry **dstp,
 589			unsigned int flags, const struct sockcm_cookie *sockc)
 590{
 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_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTREQUESTS);
 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 && !inet6_test_bit(RECVERR6, sk))
 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 (inet6_test_bit(SNDFLOW, sk)) {
 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 = READ_ONCE(np->mcast_oif);
 880	else if (!fl6.flowi6_oif)
 881		fl6.flowi6_oif = READ_ONCE(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 = inet6_test_bit(DONTFRAG, sk);
 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}
v6.13.7
   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		sk_skb_reason_drop(sk, 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		sk_skb_reason_drop(sk, 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		sk_skb_reason_drop(sk, 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			sk_skb_reason_drop(sk, 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 = dst_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_set_delivery_type_by_clockid(skb, sockc->transmit_time, sk->sk_clockid);
 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);
 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, dst_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}