xref: /openbmc/linux/net/ipv6/raw.c (revision 793245ee)

/*
 *	RAW sockets for IPv6
 *	Linux INET6 implementation
 *
 *	Authors:
 *	Pedro Roque		<roque@di.fc.ul.pt>
 *
 *	Adapted from linux/net/ipv4/raw.c
 *
 *	$Id: raw.c,v 1.51 2002/02/01 22:01:04 davem Exp $
 *
 *	Fixes:
 *	Hideaki YOSHIFUJI	:	sin6_scope_id support
 *	YOSHIFUJI,H.@USAGI	:	raw checksum (RFC2292(bis) compliance)
 *	Kazunori MIYAZAWA @USAGI:	change process style to use ip6_append_data
 *
 *	This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/sched.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/icmpv6.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>
#include <asm/uaccess.h>
#include <asm/ioctls.h>
#include <asm/bug.h>

#include <net/ip.h>
#include <net/sock.h>
#include <net/snmp.h>

#include <net/ipv6.h>
#include <net/ndisc.h>
#include <net/protocol.h>
#include <net/ip6_route.h>
#include <net/ip6_checksum.h>
#include <net/addrconf.h>
#include <net/transp_v6.h>
#include <net/udp.h>
#include <net/inet_common.h>

#include <net/rawv6.h>
#include <net/xfrm.h>

#include <linux/proc_fs.h>
#include <linux/seq_file.h>

struct hlist_head raw_v6_htable[RAWV6_HTABLE_SIZE];
DEFINE_RWLOCK(raw_v6_lock);

static void raw_v6_hash(struct sock *sk)
{
	struct hlist_head *list = &raw_v6_htable[inet_sk(sk)->num &
						 (RAWV6_HTABLE_SIZE - 1)];

	write_lock_bh(&raw_v6_lock);
	sk_add_node(sk, list);
	sock_prot_inc_use(sk->sk_prot);
 	write_unlock_bh(&raw_v6_lock);
}

static void raw_v6_unhash(struct sock *sk)
{
 	write_lock_bh(&raw_v6_lock);
	if (sk_del_node_init(sk))
		sock_prot_dec_use(sk->sk_prot);
	write_unlock_bh(&raw_v6_lock);
}


/* Grumble... icmp and ip_input want to get at this... */
struct sock *__raw_v6_lookup(struct sock *sk, unsigned short num,
			     struct in6_addr *loc_addr, struct in6_addr *rmt_addr)
{
	struct hlist_node *node;
	int is_multicast = ipv6_addr_is_multicast(loc_addr);

	sk_for_each_from(sk, node)
		if (inet_sk(sk)->num == num) {
			struct ipv6_pinfo *np = inet6_sk(sk);

			if (!ipv6_addr_any(&np->daddr) &&
			    !ipv6_addr_equal(&np->daddr, rmt_addr))
				continue;

			if (!ipv6_addr_any(&np->rcv_saddr)) {
				if (ipv6_addr_equal(&np->rcv_saddr, loc_addr))
					goto found;
				if (is_multicast &&
				    inet6_mc_check(sk, loc_addr, rmt_addr))
					goto found;
				continue;
			}
			goto found;
		}
	sk = NULL;
found:
	return sk;
}

/*
 *	0 - deliver
 *	1 - block
 */
static __inline__ int icmpv6_filter(struct sock *sk, struct sk_buff *skb)
{
	struct icmp6hdr *icmph;
	struct raw6_sock *rp = raw6_sk(sk);

	if (pskb_may_pull(skb, sizeof(struct icmp6hdr))) {
		__u32 *data = &rp->filter.data[0];
		int bit_nr;

		icmph = (struct icmp6hdr *) skb->data;
		bit_nr = icmph->icmp6_type;

		return (data[bit_nr >> 5] & (1 << (bit_nr & 31))) != 0;
	}
	return 0;
}

/*
 *	demultiplex raw sockets.
 *	(should consider queueing the skb in the sock receive_queue
 *	without calling rawv6.c)
 *
 *	Caller owns SKB so we must make clones.
 */
void ipv6_raw_deliver(struct sk_buff *skb, int nexthdr)
{
	struct in6_addr *saddr;
	struct in6_addr *daddr;
	struct sock *sk;
	__u8 hash;

	saddr = &skb->nh.ipv6h->saddr;
	daddr = saddr + 1;

	hash = nexthdr & (MAX_INET_PROTOS - 1);

	read_lock(&raw_v6_lock);
	sk = sk_head(&raw_v6_htable[hash]);

	/*
	 *	The first socket found will be delivered after
	 *	delivery to transport protocols.
	 */

	if (sk == NULL)
		goto out;

	sk = __raw_v6_lookup(sk, nexthdr, daddr, saddr);

	while (sk) {
		if (nexthdr != IPPROTO_ICMPV6 || !icmpv6_filter(sk, skb)) {
			struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC);

			/* Not releasing hash table! */
			if (clone)
				rawv6_rcv(sk, clone);
		}
		sk = __raw_v6_lookup(sk_next(sk), nexthdr, daddr, saddr);
	}
out:
	read_unlock(&raw_v6_lock);
}

/* This cleans up af_inet6 a bit. -DaveM */
static int rawv6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
	struct inet_sock *inet = inet_sk(sk);
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
	__u32 v4addr = 0;
	int addr_type;
	int err;

	if (addr_len < SIN6_LEN_RFC2133)
		return -EINVAL;
	addr_type = ipv6_addr_type(&addr->sin6_addr);

	/* Raw sockets are IPv6 only */
	if (addr_type == IPV6_ADDR_MAPPED)
		return(-EADDRNOTAVAIL);

	lock_sock(sk);

	err = -EINVAL;
	if (sk->sk_state != TCP_CLOSE)
		goto out;

	/* Check if the address belongs to the host. */
	if (addr_type != IPV6_ADDR_ANY) {
		struct net_device *dev = NULL;

		if (addr_type & IPV6_ADDR_LINKLOCAL) {
			if (addr_len >= sizeof(struct sockaddr_in6) &&
			    addr->sin6_scope_id) {
				/* Override any existing binding, if another
				 * one is supplied by user.
				 */
				sk->sk_bound_dev_if = addr->sin6_scope_id;
			}

			/* Binding to link-local address requires an interface */
			if (!sk->sk_bound_dev_if)
				goto out;

			dev = dev_get_by_index(sk->sk_bound_dev_if);
			if (!dev) {
				err = -ENODEV;
				goto out;
			}
		}

		/* ipv4 addr of the socket is invalid.  Only the
		 * unspecified and mapped address have a v4 equivalent.
		 */
		v4addr = LOOPBACK4_IPV6;
		if (!(addr_type & IPV6_ADDR_MULTICAST))	{
			err = -EADDRNOTAVAIL;
			if (!ipv6_chk_addr(&addr->sin6_addr, dev, 0)) {
				if (dev)
					dev_put(dev);
				goto out;
			}
		}
		if (dev)
			dev_put(dev);
	}

	inet->rcv_saddr = inet->saddr = v4addr;
	ipv6_addr_copy(&np->rcv_saddr, &addr->sin6_addr);
	if (!(addr_type & IPV6_ADDR_MULTICAST))
		ipv6_addr_copy(&np->saddr, &addr->sin6_addr);
	err = 0;
out:
	release_sock(sk);
	return err;
}

void rawv6_err(struct sock *sk, struct sk_buff *skb,
	       struct inet6_skb_parm *opt,
	       int type, int code, int offset, u32 info)
{
	struct inet_sock *inet = inet_sk(sk);
	struct ipv6_pinfo *np = inet6_sk(sk);
	int err;
	int harderr;

	/* Report error on raw socket, if:
	   1. User requested recverr.
	   2. Socket is connected (otherwise the error indication
	      is useless without recverr and error is hard.
	 */
	if (!np->recverr && sk->sk_state != TCP_ESTABLISHED)
		return;

	harderr = icmpv6_err_convert(type, code, &err);
	if (type == ICMPV6_PKT_TOOBIG)
		harderr = (np->pmtudisc == IPV6_PMTUDISC_DO);

	if (np->recverr) {
		u8 *payload = skb->data;
		if (!inet->hdrincl)
			payload += offset;
		ipv6_icmp_error(sk, skb, err, 0, ntohl(info), payload);
	}

	if (np->recverr || harderr) {
		sk->sk_err = err;
		sk->sk_error_report(sk);
	}
}

static inline int rawv6_rcv_skb(struct sock * sk, struct sk_buff * skb)
{
	if ((raw6_sk(sk)->checksum || sk->sk_filter) &&
	    skb->ip_summed != CHECKSUM_UNNECESSARY) {
		if ((unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum))) {
			/* FIXME: increment a raw6 drops counter here */
			kfree_skb(skb);
			return 0;
		}
		skb->ip_summed = CHECKSUM_UNNECESSARY;
	}

	/* Charge it to the socket. */
	if (sock_queue_rcv_skb(sk,skb)<0) {
		/* FIXME: increment a raw6 drops counter here */
		kfree_skb(skb);
		return 0;
	}

	return 0;
}

/*
 *	This is next to useless...
 *	if we demultiplex in network layer we don't need the extra call
 *	just to queue the skb...
 *	maybe we could have the network decide upon a hint if it
 *	should call raw_rcv for demultiplexing
 */
int rawv6_rcv(struct sock *sk, struct sk_buff *skb)
{
	struct inet_sock *inet = inet_sk(sk);
	struct raw6_sock *rp = raw6_sk(sk);

        if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
                kfree_skb(skb);
                return NET_RX_DROP;
        }

	if (!rp->checksum)
		skb->ip_summed = CHECKSUM_UNNECESSARY;

	if (skb->ip_summed != CHECKSUM_UNNECESSARY) {
		if (skb->ip_summed == CHECKSUM_HW) {
			skb_postpull_rcsum(skb, skb->nh.raw,
			                   skb->h.raw - skb->nh.raw);
			skb->ip_summed = CHECKSUM_UNNECESSARY;
			if (csum_ipv6_magic(&skb->nh.ipv6h->saddr,
					    &skb->nh.ipv6h->daddr,
					    skb->len, inet->num, skb->csum)) {
				LIMIT_NETDEBUG(
			        printk(KERN_DEBUG "raw v6 hw csum failure.\n"));
				skb->ip_summed = CHECKSUM_NONE;
			}
		}
		if (skb->ip_summed == CHECKSUM_NONE)
			skb->csum = ~csum_ipv6_magic(&skb->nh.ipv6h->saddr,
						     &skb->nh.ipv6h->daddr,
						     skb->len, inet->num, 0);
	}

	if (inet->hdrincl) {
		if (skb->ip_summed != CHECKSUM_UNNECESSARY &&
		    (unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum))) {
			/* FIXME: increment a raw6 drops counter here */
			kfree_skb(skb);
			return 0;
		}
		skb->ip_summed = CHECKSUM_UNNECESSARY;
	}

	rawv6_rcv_skb(sk, skb);
	return 0;
}


/*
 *	This should be easy, if there is something there
 *	we return it, otherwise we block.
 */

static int rawv6_recvmsg(struct kiocb *iocb, struct sock *sk,
		  struct msghdr *msg, size_t len,
		  int noblock, int flags, int *addr_len)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)msg->msg_name;
	struct sk_buff *skb;
	size_t copied;
	int err;

	if (flags & MSG_OOB)
		return -EOPNOTSUPP;

	if (addr_len)
		*addr_len=sizeof(*sin6);

	if (flags & MSG_ERRQUEUE)
		return ipv6_recv_error(sk, msg, len);

	skb = skb_recv_datagram(sk, flags, noblock, &err);
	if (!skb)
		goto out;

	copied = skb->len;
  	if (copied > len) {
  		copied = len;
  		msg->msg_flags |= MSG_TRUNC;
  	}

	if (skb->ip_summed==CHECKSUM_UNNECESSARY) {
		err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
	} else if (msg->msg_flags&MSG_TRUNC) {
		if ((unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum)))
			goto csum_copy_err;
		err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
	} else {
		err = skb_copy_and_csum_datagram_iovec(skb, 0, msg->msg_iov);
		if (err == -EINVAL)
			goto csum_copy_err;
	}
	if (err)
		goto out_free;

	/* Copy the address. */
	if (sin6) {
		sin6->sin6_family = AF_INET6;
		ipv6_addr_copy(&sin6->sin6_addr, &skb->nh.ipv6h->saddr);
		sin6->sin6_flowinfo = 0;
		sin6->sin6_scope_id = 0;
		if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
			sin6->sin6_scope_id = IP6CB(skb)->iif;
	}

	sock_recv_timestamp(msg, sk, skb);

	if (np->rxopt.all)
		datagram_recv_ctl(sk, msg, skb);

	err = copied;
	if (flags & MSG_TRUNC)
		err = skb->len;

out_free:
	skb_free_datagram(sk, skb);
out:
	return err;

csum_copy_err:
	/* Clear queue. */
	if (flags&MSG_PEEK) {
		int clear = 0;
		spin_lock_bh(&sk->sk_receive_queue.lock);
		if (skb == skb_peek(&sk->sk_receive_queue)) {
			__skb_unlink(skb, &sk->sk_receive_queue);
			clear = 1;
		}
		spin_unlock_bh(&sk->sk_receive_queue.lock);
		if (clear)
			kfree_skb(skb);
	}

	/* Error for blocking case is chosen to masquerade
	   as some normal condition.
	 */
	err = (flags&MSG_DONTWAIT) ? -EAGAIN : -EHOSTUNREACH;
	/* FIXME: increment a raw6 drops counter here */
	goto out_free;
}

static int rawv6_push_pending_frames(struct sock *sk, struct flowi *fl,
				     struct raw6_sock *rp)
{
	struct sk_buff *skb;
	int err = 0;
	int offset;
	int len;
	int total_len;
	u32 tmp_csum;
	u16 csum;

	if (!rp->checksum)
		goto send;

	if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
		goto out;

	offset = rp->offset;
	total_len = inet_sk(sk)->cork.length - (skb->nh.raw - skb->data);
	if (offset >= total_len - 1) {
		err = -EINVAL;
		ip6_flush_pending_frames(sk);
		goto out;
	}

	/* should be check HW csum miyazawa */
	if (skb_queue_len(&sk->sk_write_queue) == 1) {
		/*
		 * Only one fragment on the socket.
		 */
		tmp_csum = skb->csum;
	} else {
		struct sk_buff *csum_skb = NULL;
		tmp_csum = 0;

		skb_queue_walk(&sk->sk_write_queue, skb) {
			tmp_csum = csum_add(tmp_csum, skb->csum);

			if (csum_skb)
				continue;

			len = skb->len - (skb->h.raw - skb->data);
			if (offset >= len) {
				offset -= len;
				continue;
			}

			csum_skb = skb;
		}

		skb = csum_skb;
	}

	offset += skb->h.raw - skb->data;
	if (skb_copy_bits(skb, offset, &csum, 2))
		BUG();

	/* in case cksum was not initialized */
	if (unlikely(csum))
		tmp_csum = csum_sub(tmp_csum, csum);

	tmp_csum = csum_ipv6_magic(&fl->fl6_src,
				   &fl->fl6_dst,
				   total_len, fl->proto, tmp_csum);

	if (tmp_csum == 0)
		tmp_csum = -1;

	csum = tmp_csum;
	if (skb_store_bits(skb, offset, &csum, 2))
		BUG();

send:
	err = ip6_push_pending_frames(sk);
out:
	return err;
}

static int rawv6_send_hdrinc(struct sock *sk, void *from, int length,
			struct flowi *fl, struct rt6_info *rt,
			unsigned int flags)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct ipv6hdr *iph;
	struct sk_buff *skb;
	unsigned int hh_len;
	int err;

	if (length > rt->u.dst.dev->mtu) {
		ipv6_local_error(sk, EMSGSIZE, fl, rt->u.dst.dev->mtu);
		return -EMSGSIZE;
	}
	if (flags&MSG_PROBE)
		goto out;

	hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);

	skb = sock_alloc_send_skb(sk, length+hh_len+15,
				  flags&MSG_DONTWAIT, &err);
	if (skb == NULL)
		goto error;
	skb_reserve(skb, hh_len);

	skb->priority = sk->sk_priority;
	skb->dst = dst_clone(&rt->u.dst);

	skb->nh.ipv6h = iph = (struct ipv6hdr *)skb_put(skb, length);

	skb->ip_summed = CHECKSUM_NONE;

	skb->h.raw = skb->nh.raw;
	err = memcpy_fromiovecend((void *)iph, from, 0, length);
	if (err)
		goto error_fault;

	IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
	err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, rt->u.dst.dev,
		      dst_output);
	if (err > 0)
		err = np->recverr ? net_xmit_errno(err) : 0;
	if (err)
		goto error;
out:
	return 0;

error_fault:
	err = -EFAULT;
	kfree_skb(skb);
error:
	IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
	return err;
}

static void rawv6_probe_proto_opt(struct flowi *fl, struct msghdr *msg)
{
	struct iovec *iov;
	u8 __user *type = NULL;
	u8 __user *code = NULL;
	int probed = 0;
	int i;

	if (!msg->msg_iov)
		return;

	for (i = 0; i < msg->msg_iovlen; i++) {
		iov = &msg->msg_iov[i];
		if (!iov)
			continue;

		switch (fl->proto) {
		case IPPROTO_ICMPV6:
			/* check if one-byte field is readable or not. */
			if (iov->iov_base && iov->iov_len < 1)
				break;

			if (!type) {
				type = iov->iov_base;
				/* check if code field is readable or not. */
				if (iov->iov_len > 1)
					code = type + 1;
			} else if (!code)
				code = iov->iov_base;

			if (type && code) {
				get_user(fl->fl_icmp_type, type);
				__get_user(fl->fl_icmp_code, code);
				probed = 1;
			}
			break;
		default:
			probed = 1;
			break;
		}
		if (probed)
			break;
	}
}

static int rawv6_sendmsg(struct kiocb *iocb, struct sock *sk,
		   struct msghdr *msg, size_t len)
{
	struct ipv6_txoptions opt_space;
	struct sockaddr_in6 * sin6 = (struct sockaddr_in6 *) msg->msg_name;
	struct in6_addr *daddr, *final_p = NULL, final;
	struct inet_sock *inet = inet_sk(sk);
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct raw6_sock *rp = raw6_sk(sk);
	struct ipv6_txoptions *opt = NULL;
	struct ip6_flowlabel *flowlabel = NULL;
	struct dst_entry *dst = NULL;
	struct flowi fl;
	int addr_len = msg->msg_namelen;
	int hlimit = -1;
	u16 proto;
	int err;

	/* Rough check on arithmetic overflow,
	   better check is made in ip6_build_xmit
	 */
	if (len < 0)
		return -EMSGSIZE;

	/* Mirror BSD error message compatibility */
	if (msg->msg_flags & MSG_OOB)
		return -EOPNOTSUPP;

	/*
	 *	Get and verify the address.
	 */
	memset(&fl, 0, sizeof(fl));

	if (sin6) {
		if (addr_len < SIN6_LEN_RFC2133)
			return -EINVAL;

		if (sin6->sin6_family && sin6->sin6_family != AF_INET6)
			return(-EAFNOSUPPORT);

		/* port is the proto value [0..255] carried in nexthdr */
		proto = ntohs(sin6->sin6_port);

		if (!proto)
			proto = inet->num;
		else if (proto != inet->num)
			return(-EINVAL);

		if (proto > 255)
			return(-EINVAL);

		daddr = &sin6->sin6_addr;
		if (np->sndflow) {
			fl.fl6_flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
			if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
				flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
				if (flowlabel == NULL)
					return -EINVAL;
				daddr = &flowlabel->dst;
			}
		}

		/*
		 * Otherwise it will be difficult to maintain
		 * sk->sk_dst_cache.
		 */
		if (sk->sk_state == TCP_ESTABLISHED &&
		    ipv6_addr_equal(daddr, &np->daddr))
			daddr = &np->daddr;

		if (addr_len >= sizeof(struct sockaddr_in6) &&
		    sin6->sin6_scope_id &&
		    ipv6_addr_type(daddr)&IPV6_ADDR_LINKLOCAL)
			fl.oif = sin6->sin6_scope_id;
	} else {
		if (sk->sk_state != TCP_ESTABLISHED)
			return -EDESTADDRREQ;

		proto = inet->num;
		daddr = &np->daddr;
		fl.fl6_flowlabel = np->flow_label;
	}

	if (ipv6_addr_any(daddr)) {
		/*
		 * unspecified destination address
		 * treated as error... is this correct ?
		 */
		fl6_sock_release(flowlabel);
		return(-EINVAL);
	}

	if (fl.oif == 0)
		fl.oif = sk->sk_bound_dev_if;

	if (msg->msg_controllen) {
		opt = &opt_space;
		memset(opt, 0, sizeof(struct ipv6_txoptions));
		opt->tot_len = sizeof(struct ipv6_txoptions);

		err = datagram_send_ctl(msg, &fl, opt, &hlimit);
		if (err < 0) {
			fl6_sock_release(flowlabel);
			return err;
		}
		if ((fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
			flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
			if (flowlabel == NULL)
				return -EINVAL;
		}
		if (!(opt->opt_nflen|opt->opt_flen))
			opt = NULL;
	}
	if (opt == NULL)
		opt = np->opt;
	if (flowlabel)
		opt = fl6_merge_options(&opt_space, flowlabel, opt);

	fl.proto = proto;
	rawv6_probe_proto_opt(&fl, msg);

	ipv6_addr_copy(&fl.fl6_dst, daddr);
	if (ipv6_addr_any(&fl.fl6_src) && !ipv6_addr_any(&np->saddr))
		ipv6_addr_copy(&fl.fl6_src, &np->saddr);

	/* merge ip6_build_xmit from ip6_output */
	if (opt && opt->srcrt) {
		struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
		ipv6_addr_copy(&final, &fl.fl6_dst);
		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
		final_p = &final;
	}

	if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst))
		fl.oif = np->mcast_oif;

	err = ip6_dst_lookup(sk, &dst, &fl);
	if (err)
		goto out;
	if (final_p)
		ipv6_addr_copy(&fl.fl6_dst, final_p);

	if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) {
		dst_release(dst);
		goto out;
	}

	if (hlimit < 0) {
		if (ipv6_addr_is_multicast(&fl.fl6_dst))
			hlimit = np->mcast_hops;
		else
			hlimit = np->hop_limit;
		if (hlimit < 0)
			hlimit = dst_metric(dst, RTAX_HOPLIMIT);
		if (hlimit < 0)
			hlimit = ipv6_get_hoplimit(dst->dev);
	}

	if (msg->msg_flags&MSG_CONFIRM)
		goto do_confirm;

back_from_confirm:
	if (inet->hdrincl) {
		err = rawv6_send_hdrinc(sk, msg->msg_iov, len, &fl, (struct rt6_info*)dst, msg->msg_flags);
	} else {
		lock_sock(sk);
		err = ip6_append_data(sk, ip_generic_getfrag, msg->msg_iov, len, 0,
					hlimit, opt, &fl, (struct rt6_info*)dst, msg->msg_flags);

		if (err)
			ip6_flush_pending_frames(sk);
		else if (!(msg->msg_flags & MSG_MORE))
			err = rawv6_push_pending_frames(sk, &fl, rp);
	}
done:
	ip6_dst_store(sk, dst,
		      ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
		      &np->daddr : NULL);

	release_sock(sk);
out:
	fl6_sock_release(flowlabel);
	return err<0?err:len;
do_confirm:
	dst_confirm(dst);
	if (!(msg->msg_flags & MSG_PROBE) || len)
		goto back_from_confirm;
	err = 0;
	goto done;
}

static int rawv6_seticmpfilter(struct sock *sk, int level, int optname,
			       char __user *optval, int optlen)
{
	switch (optname) {
	case ICMPV6_FILTER:
		if (optlen > sizeof(struct icmp6_filter))
			optlen = sizeof(struct icmp6_filter);
		if (copy_from_user(&raw6_sk(sk)->filter, optval, optlen))
			return -EFAULT;
		return 0;
	default:
		return -ENOPROTOOPT;
	};

	return 0;
}

static int rawv6_geticmpfilter(struct sock *sk, int level, int optname,
			       char __user *optval, int __user *optlen)
{
	int len;

	switch (optname) {
	case ICMPV6_FILTER:
		if (get_user(len, optlen))
			return -EFAULT;
		if (len < 0)
			return -EINVAL;
		if (len > sizeof(struct icmp6_filter))
			len = sizeof(struct icmp6_filter);
		if (put_user(len, optlen))
			return -EFAULT;
		if (copy_to_user(optval, &raw6_sk(sk)->filter, len))
			return -EFAULT;
		return 0;
	default:
		return -ENOPROTOOPT;
	};

	return 0;
}


static int rawv6_setsockopt(struct sock *sk, int level, int optname,
			    char __user *optval, int optlen)
{
	struct raw6_sock *rp = raw6_sk(sk);
	int val;

	switch(level) {
		case SOL_RAW:
			break;

		case SOL_ICMPV6:
			if (inet_sk(sk)->num != IPPROTO_ICMPV6)
				return -EOPNOTSUPP;
			return rawv6_seticmpfilter(sk, level, optname, optval,
						   optlen);
		case SOL_IPV6:
			if (optname == IPV6_CHECKSUM)
				break;
		default:
			return ipv6_setsockopt(sk, level, optname, optval,
					       optlen);
	};

  	if (get_user(val, (int __user *)optval))
		return -EFAULT;

	switch (optname) {
		case IPV6_CHECKSUM:
			/* You may get strange result with a positive odd offset;
			   RFC2292bis agrees with me. */
			if (val > 0 && (val&1))
				return(-EINVAL);
			if (val < 0) {
				rp->checksum = 0;
			} else {
				rp->checksum = 1;
				rp->offset = val;
			}

			return 0;
			break;

		default:
			return(-ENOPROTOOPT);
	}
}

static int rawv6_getsockopt(struct sock *sk, int level, int optname,
			    char __user *optval, int __user *optlen)
{
	struct raw6_sock *rp = raw6_sk(sk);
	int val, len;

	switch(level) {
		case SOL_RAW:
			break;

		case SOL_ICMPV6:
			if (inet_sk(sk)->num != IPPROTO_ICMPV6)
				return -EOPNOTSUPP;
			return rawv6_geticmpfilter(sk, level, optname, optval,
						   optlen);
		case SOL_IPV6:
			if (optname == IPV6_CHECKSUM)
				break;
		default:
			return ipv6_getsockopt(sk, level, optname, optval,
					       optlen);
	};

	if (get_user(len,optlen))
		return -EFAULT;

	switch (optname) {
	case IPV6_CHECKSUM:
		if (rp->checksum == 0)
			val = -1;
		else
			val = rp->offset;
		break;

	default:
		return -ENOPROTOOPT;
	}

	len = min_t(unsigned int, sizeof(int), len);

	if (put_user(len, optlen))
		return -EFAULT;
	if (copy_to_user(optval,&val,len))
		return -EFAULT;
	return 0;
}

static int rawv6_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
	switch(cmd) {
		case SIOCOUTQ:
		{
			int amount = atomic_read(&sk->sk_wmem_alloc);
			return put_user(amount, (int __user *)arg);
		}
		case SIOCINQ:
		{
			struct sk_buff *skb;
			int amount = 0;

			spin_lock_bh(&sk->sk_receive_queue.lock);
			skb = skb_peek(&sk->sk_receive_queue);
			if (skb != NULL)
				amount = skb->tail - skb->h.raw;
			spin_unlock_bh(&sk->sk_receive_queue.lock);
			return put_user(amount, (int __user *)arg);
		}

		default:
			return -ENOIOCTLCMD;
	}
}

static void rawv6_close(struct sock *sk, long timeout)
{
	if (inet_sk(sk)->num == IPPROTO_RAW)
		ip6_ra_control(sk, -1, NULL);

	sk_common_release(sk);
}

static int rawv6_init_sk(struct sock *sk)
{
	if (inet_sk(sk)->num == IPPROTO_ICMPV6) {
		struct raw6_sock *rp = raw6_sk(sk);
		rp->checksum = 1;
		rp->offset   = 2;
	}
	return(0);
}

struct proto rawv6_prot = {
	.name =		"RAWv6",
	.owner =	THIS_MODULE,
	.close =	rawv6_close,
	.connect =	ip6_datagram_connect,
	.disconnect =	udp_disconnect,
	.ioctl =	rawv6_ioctl,
	.init =		rawv6_init_sk,
	.destroy =	inet6_destroy_sock,
	.setsockopt =	rawv6_setsockopt,
	.getsockopt =	rawv6_getsockopt,
	.sendmsg =	rawv6_sendmsg,
	.recvmsg =	rawv6_recvmsg,
	.bind =		rawv6_bind,
	.backlog_rcv =	rawv6_rcv_skb,
	.hash =		raw_v6_hash,
	.unhash =	raw_v6_unhash,
	.obj_size =	sizeof(struct raw6_sock),
};

#ifdef CONFIG_PROC_FS
struct raw6_iter_state {
	int bucket;
};

#define raw6_seq_private(seq) ((struct raw6_iter_state *)(seq)->private)

static struct sock *raw6_get_first(struct seq_file *seq)
{
	struct sock *sk;
	struct hlist_node *node;
	struct raw6_iter_state* state = raw6_seq_private(seq);

	for (state->bucket = 0; state->bucket < RAWV6_HTABLE_SIZE; ++state->bucket)
		sk_for_each(sk, node, &raw_v6_htable[state->bucket])
			if (sk->sk_family == PF_INET6)
				goto out;
	sk = NULL;
out:
	return sk;
}

static struct sock *raw6_get_next(struct seq_file *seq, struct sock *sk)
{
	struct raw6_iter_state* state = raw6_seq_private(seq);

	do {
		sk = sk_next(sk);
try_again:
		;
	} while (sk && sk->sk_family != PF_INET6);

	if (!sk && ++state->bucket < RAWV6_HTABLE_SIZE) {
		sk = sk_head(&raw_v6_htable[state->bucket]);
		goto try_again;
	}
	return sk;
}

static struct sock *raw6_get_idx(struct seq_file *seq, loff_t pos)
{
	struct sock *sk = raw6_get_first(seq);
	if (sk)
		while (pos && (sk = raw6_get_next(seq, sk)) != NULL)
			--pos;
	return pos ? NULL : sk;
}

static void *raw6_seq_start(struct seq_file *seq, loff_t *pos)
{
	read_lock(&raw_v6_lock);
	return *pos ? raw6_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
}

static void *raw6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct sock *sk;

	if (v == SEQ_START_TOKEN)
		sk = raw6_get_first(seq);
	else
		sk = raw6_get_next(seq, v);
	++*pos;
	return sk;
}

static void raw6_seq_stop(struct seq_file *seq, void *v)
{
	read_unlock(&raw_v6_lock);
}

static void raw6_sock_seq_show(struct seq_file *seq, struct sock *sp, int i)
{
	struct ipv6_pinfo *np = inet6_sk(sp);
	struct in6_addr *dest, *src;
	__u16 destp, srcp;

	dest  = &np->daddr;
	src   = &np->rcv_saddr;
	destp = 0;
	srcp  = inet_sk(sp)->num;
	seq_printf(seq,
		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p\n",
		   i,
		   src->s6_addr32[0], src->s6_addr32[1],
		   src->s6_addr32[2], src->s6_addr32[3], srcp,
		   dest->s6_addr32[0], dest->s6_addr32[1],
		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
		   sp->sk_state,
		   atomic_read(&sp->sk_wmem_alloc),
		   atomic_read(&sp->sk_rmem_alloc),
		   0, 0L, 0,
		   sock_i_uid(sp), 0,
		   sock_i_ino(sp),
		   atomic_read(&sp->sk_refcnt), sp);
}

static int raw6_seq_show(struct seq_file *seq, void *v)
{
	if (v == SEQ_START_TOKEN)
		seq_printf(seq,
			   "  sl  "
			   "local_address                         "
			   "remote_address                        "
			   "st tx_queue rx_queue tr tm->when retrnsmt"
			   "   uid  timeout inode\n");
	else
		raw6_sock_seq_show(seq, v, raw6_seq_private(seq)->bucket);
	return 0;
}

static struct seq_operations raw6_seq_ops = {
	.start =	raw6_seq_start,
	.next =		raw6_seq_next,
	.stop =		raw6_seq_stop,
	.show =		raw6_seq_show,
};

static int raw6_seq_open(struct inode *inode, struct file *file)
{
	struct seq_file *seq;
	int rc = -ENOMEM;
	struct raw6_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
	if (!s)
		goto out;
	rc = seq_open(file, &raw6_seq_ops);
	if (rc)
		goto out_kfree;
	seq = file->private_data;
	seq->private = s;
	memset(s, 0, sizeof(*s));
out:
	return rc;
out_kfree:
	kfree(s);
	goto out;
}

static struct file_operations raw6_seq_fops = {
	.owner =	THIS_MODULE,
	.open =		raw6_seq_open,
	.read =		seq_read,
	.llseek =	seq_lseek,
	.release =	seq_release_private,
};

int __init raw6_proc_init(void)
{
	if (!proc_net_fops_create("raw6", S_IRUGO, &raw6_seq_fops))
		return -ENOMEM;
	return 0;
}

void raw6_proc_exit(void)
{
	proc_net_remove("raw6");
}
#endif	/* CONFIG_PROC_FS */