text: /*
   *	common UDP/RAW code
   *	Linux INET6 implementation
   *
   *	Authors:
   *	Pedro Roque		<roque@di.fc.ul.pt>
   *
   *	$Id: datagram.c,v 1.1.1.1 2007-05-25 06:49:59 bruce Exp $
   *
   *	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/capability.h>
  #include <linux/errno.h>
  #include <linux/types.h>
  #include <linux/kernel.h>
  #include <linux/interrupt.h>
  #include <linux/socket.h>
  #include <linux/sockios.h>
  #include <linux/in6.h>
  #include <linux/ipv6.h>
  #include <linux/route.h>
  
  #include <net/ipv6.h>
  #include <net/ndisc.h>
  #include <net/addrconf.h>
  #include <net/transp_v6.h>
  #include <net/ip6_route.h>
  #include <net/tcp_states.h>
  
  #include <linux/errqueue.h>
  #include <asm/uaccess.h>
  
  int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
  {
  	struct sockaddr_in6	*usin = (struct sockaddr_in6 *) uaddr;
  	struct inet_sock      	*inet = inet_sk(sk);
  	struct ipv6_pinfo      	*np = inet6_sk(sk);
  	struct in6_addr		*daddr, *final_p = NULL, final;
  	struct dst_entry	*dst;
  	struct flowi		fl;
  	struct ip6_flowlabel	*flowlabel = NULL;
  	int			addr_type;
  	int			err;
  
  	if (usin->sin6_family == AF_INET) {
  		if (__ipv6_only_sock(sk))
  			return -EAFNOSUPPORT;
  		err = ip4_datagram_connect(sk, uaddr, addr_len);
  		goto ipv4_connected;
  	}
  
  	if (addr_len < SIN6_LEN_RFC2133)
  		return -EINVAL;
  
  	if (usin->sin6_family != AF_INET6)
  		return -EAFNOSUPPORT;
  
  	memset(&fl, 0, sizeof(fl));
  	if (np->sndflow) {
  		fl.fl6_flowlabel = usin->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;
  			ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
  		}
  	}
  
  	addr_type = ipv6_addr_type(&usin->sin6_addr);
  
  	if (addr_type == IPV6_ADDR_ANY) {
  		/*
  		 *	connect to self
  		 */
  		usin->sin6_addr.s6_addr[15] = 0x01;
  	}
  
  	daddr = &usin->sin6_addr;
  
  	if (addr_type == IPV6_ADDR_MAPPED) {
  		struct sockaddr_in sin;
  
  		if (__ipv6_only_sock(sk)) {
  			err = -ENETUNREACH;
  			goto out;
  		}
  		sin.sin_family = AF_INET;
  		sin.sin_addr.s_addr = daddr->s6_addr32[3];
  		sin.sin_port = usin->sin6_port;
  
  		err = ip4_datagram_connect(sk,
  					   (struct sockaddr*) &sin,
  					   sizeof(sin));
  
  ipv4_connected:
  		if (err)
  			goto out;
  
  		ipv6_addr_set(&np->daddr, 0, 0, htonl(0x0000ffff), inet->daddr);
  
  		if (ipv6_addr_any(&np->saddr)) {
  			ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000ffff),
  				      inet->saddr);
  		}
  
  		if (ipv6_addr_any(&np->rcv_saddr)) {
  			ipv6_addr_set(&np->rcv_saddr, 0, 0, htonl(0x0000ffff),
  				      inet->rcv_saddr);
  		}
  		goto out;
  	}
  
  	if (addr_type&IPV6_ADDR_LINKLOCAL) {
  		if (addr_len >= sizeof(struct sockaddr_in6) &&
  		    usin->sin6_scope_id) {
  			if (sk->sk_bound_dev_if &&
  			    sk->sk_bound_dev_if != usin->sin6_scope_id) {
  				err = -EINVAL;
  				goto out;
  			}
  			sk->sk_bound_dev_if = usin->sin6_scope_id;
  			if (!sk->sk_bound_dev_if &&
  			    (addr_type & IPV6_ADDR_MULTICAST))
  				fl.oif = np->mcast_oif;
  		}
  
  		/* Connect to link-local address requires an interface */
  		if (!sk->sk_bound_dev_if) {
  			err = -EINVAL;
  			goto out;
  		}
  	}
  
  	ipv6_addr_copy(&np->daddr, daddr);
  	np->flow_label = fl.fl6_flowlabel;
  
  	inet->dport = usin->sin6_port;
  
  	/*
  	 *	Check for a route to destination an obtain the
  	 *	destination cache for it.
  	 */
  
  	fl.proto = sk->sk_protocol;
  	ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
  	ipv6_addr_copy(&fl.fl6_src, &np->saddr);
  	fl.oif = sk->sk_bound_dev_if;
  	fl.fl_ip_dport = inet->dport;
  	fl.fl_ip_sport = inet->sport;
  
  	if (!fl.oif && (addr_type&IPV6_ADDR_MULTICAST))
  		fl.oif = np->mcast_oif;
  
  	security_sk_classify_flow(sk, &fl);
  
  	if (flowlabel) {
  		if (flowlabel->opt && flowlabel->opt->srcrt) {
  			struct rt0_hdr *rt0 = (struct rt0_hdr *) flowlabel->opt->srcrt;
  			ipv6_addr_copy(&final, &fl.fl6_dst);
  			ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
  			final_p = &final;
  		}
  	} else if (np->opt && np->opt->srcrt) {
  		struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
  		ipv6_addr_copy(&final, &fl.fl6_dst);
  		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
  		final_p = &final;
  	}
  
  	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, 1)) < 0)
  		goto out;
  
  	/* source address lookup done in ip6_dst_lookup */
  
  	if (ipv6_addr_any(&np->saddr))
  		ipv6_addr_copy(&np->saddr, &fl.fl6_src);
  
  	if (ipv6_addr_any(&np->rcv_saddr)) {
  		ipv6_addr_copy(&np->rcv_saddr, &fl.fl6_src);
  		inet->rcv_saddr = LOOPBACK4_IPV6;
  	}
  
  	ip6_dst_store(sk, dst,
  		      ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
  		      &np->daddr : NULL,
  #ifdef CONFIG_IPV6_SUBTREES
  		      ipv6_addr_equal(&fl.fl6_src, &np->saddr) ?
  		      &np->saddr :
  #endif
  		      NULL);
  
  	sk->sk_state = TCP_ESTABLISHED;
  out:
  	fl6_sock_release(flowlabel);
  	return err;
  }
  
  void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
  		     __be16 port, u32 info, u8 *payload)
  {
  	struct ipv6_pinfo *np  = inet6_sk(sk);
  	struct icmp6hdr *icmph = (struct icmp6hdr *)skb->h.raw;
  	struct sock_exterr_skb *serr;
  
  	if (!np->recverr)
  		return;
  
  	skb = skb_clone(skb, GFP_ATOMIC);
  	if (!skb)
  		return;
  
  	serr = SKB_EXT_ERR(skb);
  	serr->ee.ee_errno = err;
  	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
  	serr->ee.ee_type = icmph->icmp6_type;
  	serr->ee.ee_code = icmph->icmp6_code;
  	serr->ee.ee_pad = 0;
  	serr->ee.ee_info = info;
  	serr->ee.ee_data = 0;
  	serr->addr_offset = (u8*)&(((struct ipv6hdr*)(icmph+1))->daddr) - skb->nh.raw;
  	serr->port = port;
  
  	skb->h.raw = payload;
  	__skb_pull(skb, payload - skb->data);
  
  	if (sock_queue_err_skb(sk, skb))
  		kfree_skb(skb);
  }
  
  void ipv6_local_error(struct sock *sk, int err, struct flowi *fl, u32 info)
  {
  	struct ipv6_pinfo *np = inet6_sk(sk);
  	struct sock_exterr_skb *serr;
  	struct ipv6hdr *iph;
  	struct sk_buff *skb;
  
  	if (!np->recverr)
  		return;
  
  	skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
  	if (!skb)
  		return;
  
  	iph = (struct ipv6hdr*)skb_put(skb, sizeof(struct ipv6hdr));
  	skb->nh.ipv6h = iph;
  	ipv6_addr_copy(&iph->daddr, &fl->fl6_dst);
  
  	serr = SKB_EXT_ERR(skb);
  	serr->ee.ee_errno = err;
  	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
  	serr->ee.ee_type = 0;
  	serr->ee.ee_code = 0;
  	serr->ee.ee_pad = 0;
  	serr->ee.ee_info = info;
  	serr->ee.ee_data = 0;
  	serr->addr_offset = (u8*)&iph->daddr - skb->nh.raw;
  	serr->port = fl->fl_ip_dport;
  
  	skb->h.raw = skb->tail;
  	__skb_pull(skb, skb->tail - skb->data);
  
  	if (sock_queue_err_skb(sk, skb))
  		kfree_skb(skb);
  }
  
  /*
   *	Handle MSG_ERRQUEUE
   */
  int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
  {
  	struct ipv6_pinfo *np = inet6_sk(sk);
  	struct sock_exterr_skb *serr;
  	struct sk_buff *skb, *skb2;
  	struct sockaddr_in6 *sin;
  	struct {
  		struct sock_extended_err ee;
  		struct sockaddr_in6	 offender;
  	} errhdr;
  	int err;
  	int copied;
  
  	err = -EAGAIN;
  	skb = skb_dequeue(&sk->sk_error_queue);
  	if (skb == NULL)
  		goto out;
  
  	copied = skb->len;
  	if (copied > len) {
  		msg->msg_flags |= MSG_TRUNC;
  		copied = len;
  	}
  	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
  	if (err)
  		goto out_free_skb;
  
  	sock_recv_timestamp(msg, sk, skb);
  
  	serr = SKB_EXT_ERR(skb);
  
  	sin = (struct sockaddr_in6 *)msg->msg_name;
  	if (sin) {
  		sin->sin6_family = AF_INET6;
  		sin->sin6_flowinfo = 0;
  		sin->sin6_port = serr->port;
  		sin->sin6_scope_id = 0;
  		if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
  			ipv6_addr_copy(&sin->sin6_addr,
  			  (struct in6_addr *)(skb->nh.raw + serr->addr_offset));
  			if (np->sndflow)
  				sin->sin6_flowinfo = *(__be32*)(skb->nh.raw + serr->addr_offset - 24) & IPV6_FLOWINFO_MASK;
  			if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
  				sin->sin6_scope_id = IP6CB(skb)->iif;
  		} else {
  			ipv6_addr_set(&sin->sin6_addr, 0, 0,
  				      htonl(0xffff),
  				      *(__be32*)(skb->nh.raw + serr->addr_offset));
  		}
  	}
  
  	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
  	sin = &errhdr.offender;
  	sin->sin6_family = AF_UNSPEC;
  	if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
  		sin->sin6_family = AF_INET6;
  		sin->sin6_flowinfo = 0;
  		sin->sin6_scope_id = 0;
  		if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
  			ipv6_addr_copy(&sin->sin6_addr, &skb->nh.ipv6h->saddr);
  			if (np->rxopt.all)
  				datagram_recv_ctl(sk, msg, skb);
  			if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
  				sin->sin6_scope_id = IP6CB(skb)->iif;
  		} else {
  			struct inet_sock *inet = inet_sk(sk);
  
  			ipv6_addr_set(&sin->sin6_addr, 0, 0,
  				      htonl(0xffff),
  				      skb->nh.iph->saddr);
  			if (inet->cmsg_flags)
  				ip_cmsg_recv(msg, skb);
  		}
  	}
  
  	put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
  
  	/* Now we could try to dump offended packet options */
  
  	msg->msg_flags |= MSG_ERRQUEUE;
  	err = copied;
  
  	/* Reset and regenerate socket error */
  	spin_lock_bh(&sk->sk_error_queue.lock);
  	sk->sk_err = 0;
  	if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
  		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
  		spin_unlock_bh(&sk->sk_error_queue.lock);
  		sk->sk_error_report(sk);
  	} else {
  		spin_unlock_bh(&sk->sk_error_queue.lock);
  	}
  
  out_free_skb:
  	kfree_skb(skb);
  out:
  	return err;
  }
  
  
  
  int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
  {
  	struct ipv6_pinfo *np = inet6_sk(sk);
  	struct inet6_skb_parm *opt = IP6CB(skb);
  
  	if (np->rxopt.bits.rxinfo) {
  		struct in6_pktinfo src_info;
  
  		src_info.ipi6_ifindex = opt->iif;
  		ipv6_addr_copy(&src_info.ipi6_addr, &skb->nh.ipv6h->daddr);
  		put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
  	}
  
  	if (np->rxopt.bits.rxhlim) {
  		int hlim = skb->nh.ipv6h->hop_limit;
  		put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
  	}
  
  	if (np->rxopt.bits.rxtclass) {
  		int tclass = (ntohl(*(__be32 *)skb->nh.ipv6h) >> 20) & 0xff;
  		put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
  	}
  
  	if (np->rxopt.bits.rxflow && (*(__be32*)skb->nh.raw & IPV6_FLOWINFO_MASK)) {
  		__be32 flowinfo = *(__be32*)skb->nh.raw & IPV6_FLOWINFO_MASK;
  		put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
  	}
  
  	/* HbH is allowed only once */
  	if (np->rxopt.bits.hopopts && opt->hop) {
  		u8 *ptr = skb->nh.raw + opt->hop;
  		put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
  	}
  
  	if (opt->lastopt &&
  	    (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
  		/*
  		 * Silly enough, but we need to reparse in order to
  		 * report extension headers (except for HbH)
  		 * in order.
  		 *
  		 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
  		 * (and WILL NOT be) defined because
  		 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
  		 */
  		unsigned int off = sizeof(struct ipv6hdr);
  		u8 nexthdr = skb->nh.ipv6h->nexthdr;
  
  		while (off <= opt->lastopt) {
  			unsigned len;
  			u8 *ptr = skb->nh.raw + off;
  
  			switch(nexthdr) {
  			case IPPROTO_DSTOPTS:
  				nexthdr = ptr[0];
  				len = (ptr[1] + 1) << 3;
  				if (np->rxopt.bits.dstopts)
  					put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
  				break;
  			case IPPROTO_ROUTING:
  				nexthdr = ptr[0];
  				len = (ptr[1] + 1) << 3;
  				if (np->rxopt.bits.srcrt)
  					put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
  				break;
  			case IPPROTO_AH:
  				nexthdr = ptr[0];
  				len = (ptr[1] + 2) << 2;
  				break;
  			default:
  				nexthdr = ptr[0];
  				len = (ptr[1] + 1) << 3;
  				break;
  			}
  
  			off += len;
  		}
  	}
  
  	/* socket options in old style */
  	if (np->rxopt.bits.rxoinfo) {
  		struct in6_pktinfo src_info;
  
  		src_info.ipi6_ifindex = opt->iif;
  		ipv6_addr_copy(&src_info.ipi6_addr, &skb->nh.ipv6h->daddr);
  		put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
  	}
  	if (np->rxopt.bits.rxohlim) {
  		int hlim = skb->nh.ipv6h->hop_limit;
  		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
  	}
  	if (np->rxopt.bits.ohopopts && opt->hop) {
  		u8 *ptr = skb->nh.raw + opt->hop;
  		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
  	}
  	if (np->rxopt.bits.odstopts && opt->dst0) {
  		u8 *ptr = skb->nh.raw + opt->dst0;
  		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
  	}
  	if (np->rxopt.bits.osrcrt && opt->srcrt) {
  		struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(skb->nh.raw + opt->srcrt);
  		put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
  	}
  	if (np->rxopt.bits.odstopts && opt->dst1) {
  		u8 *ptr = skb->nh.raw + opt->dst1;
  		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
  	}
  	return 0;
  }
  
  int datagram_send_ctl(struct msghdr *msg, struct flowi *fl,
  		      struct ipv6_txoptions *opt,
  		      int *hlimit, int *tclass)
  {
  	struct in6_pktinfo *src_info;
  	struct cmsghdr *cmsg;
  	struct ipv6_rt_hdr *rthdr;
  	struct ipv6_opt_hdr *hdr;
  	int len;
  	int err = 0;
  
  	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
  		int addr_type;
  		struct net_device *dev = NULL;
  
  		if (!CMSG_OK(msg, cmsg)) {
  			err = -EINVAL;
  			goto exit_f;
  		}
  
  		if (cmsg->cmsg_level != SOL_IPV6)
  			continue;
  
  		switch (cmsg->cmsg_type) {
  		case IPV6_PKTINFO:
  		case IPV6_2292PKTINFO:
  			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
  				err = -EINVAL;
  				goto exit_f;
  			}
  
  			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
  
  			if (src_info->ipi6_ifindex) {
  				if (fl->oif && src_info->ipi6_ifindex != fl->oif)
  					return -EINVAL;
  				fl->oif = src_info->ipi6_ifindex;
  			}
  
  			addr_type = ipv6_addr_type(&src_info->ipi6_addr);
  
  			if (addr_type == IPV6_ADDR_ANY)
  				break;
  
  			if (addr_type & IPV6_ADDR_LINKLOCAL) {
  				if (!src_info->ipi6_ifindex)
  					return -EINVAL;
  				else {
  					dev = dev_get_by_index(src_info->ipi6_ifindex);
  					if (!dev)
  						return -ENODEV;
  				}
  			}
  			if (!ipv6_chk_addr(&src_info->ipi6_addr, dev, 0)) {
  				if (dev)
  					dev_put(dev);
  				err = -EINVAL;
  				goto exit_f;
  			}
  			if (dev)
  				dev_put(dev);
  
  			ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
  			break;
  
  		case IPV6_FLOWINFO:
  			if (cmsg->cmsg_len < CMSG_LEN(4)) {
  				err = -EINVAL;
  				goto exit_f;
  			}
  
  			if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) {
  				if ((fl->fl6_flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
  					err = -EINVAL;
  					goto exit_f;
  				}
  			}
  			fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
  			break;
  
  		case IPV6_2292HOPOPTS:
  		case IPV6_HOPOPTS:
  			if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
  				err = -EINVAL;
  				goto exit_f;
  			}
  
  			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
  			len = ((hdr->hdrlen + 1) << 3);
  			if (cmsg->cmsg_len < CMSG_LEN(len)) {
  				err = -EINVAL;
  				goto exit_f;
  			}
  			if (!capable(CAP_NET_RAW)) {
  				err = -EPERM;
  				goto exit_f;
  			}
  			opt->opt_nflen += len;
  			opt->hopopt = hdr;
  			break;
  
  		case IPV6_2292DSTOPTS:
  			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
  				err = -EINVAL;
  				goto exit_f;
  			}
  
  			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
  			len = ((hdr->hdrlen + 1) << 3);
  			if (cmsg->cmsg_len < CMSG_LEN(len)) {
  				err = -EINVAL;
  				goto exit_f;
  			}
  			if (!capable(CAP_NET_RAW)) {
  				err = -EPERM;
  				goto exit_f;
  			}
  			if (opt->dst1opt) {
  				err = -EINVAL;
  				goto exit_f;
  			}
  			opt->opt_flen += len;
  			opt->dst1opt = hdr;
  			break;
  
  		case IPV6_DSTOPTS:
  		case IPV6_RTHDRDSTOPTS:
  			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
  				err = -EINVAL;
  				goto exit_f;
  			}
  
  			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
  			len = ((hdr->hdrlen + 1) << 3);
  			if (cmsg->cmsg_len < CMSG_LEN(len)) {
  				err = -EINVAL;
  				goto exit_f;
  			}
  			if (!capable(CAP_NET_RAW)) {
  				err = -EPERM;
  				goto exit_f;
  			}
  			if (cmsg->cmsg_type == IPV6_DSTOPTS) {
  				opt->opt_flen += len;
  				opt->dst1opt = hdr;
  			} else {
  				opt->opt_nflen += len;
  				opt->dst0opt = hdr;
  			}
  			break;
  
  		case IPV6_2292RTHDR:
  		case IPV6_RTHDR:
  			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
  				err = -EINVAL;
  				goto exit_f;
  			}
  
  			rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
  
  			switch (rthdr->type) {
  #ifdef CONFIG_IPV6_MIP6
  			case IPV6_SRCRT_TYPE_2:
  				if (rthdr->hdrlen != 2 ||
  				    rthdr->segments_left != 1) {
  				       err = -EINVAL;
  				       goto exit_f;
  				}
  				break;
  #endif
  			default:
  				err = -EINVAL;
  				goto exit_f;
  			}
  
  			len = ((rthdr->hdrlen + 1) << 3);
  
  			if (cmsg->cmsg_len < CMSG_LEN(len)) {
  				err = -EINVAL;
  				goto exit_f;
  			}
  
  			/* segments left must also match */
  			if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
  				err = -EINVAL;
  				goto exit_f;
  			}
  
  			opt->opt_nflen += len;
  			opt->srcrt = rthdr;
  
  			if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
  				int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
  
  				opt->opt_nflen += dsthdrlen;
  				opt->dst0opt = opt->dst1opt;
  				opt->dst1opt = NULL;
  				opt->opt_flen -= dsthdrlen;
  			}
  
  			break;
  
  		case IPV6_2292HOPLIMIT:
  		case IPV6_HOPLIMIT:
  			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
  				err = -EINVAL;
  				goto exit_f;
  			}
  
  			*hlimit = *(int *)CMSG_DATA(cmsg);
  			break;
  
  		case IPV6_TCLASS:
  		    {
  			int tc;
  
  			err = -EINVAL;
  			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
  				goto exit_f;
  			}
  
  			tc = *(int *)CMSG_DATA(cmsg);
  			if (tc < -1 || tc > 0xff)
  				goto exit_f;
  
  			err = 0;
  			*tclass = tc;
  
  			break;
  		    }
  		default:
  			LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
  				       cmsg->cmsg_type);
  			err = -EINVAL;
  			break;
  		};
  	}
  
  exit_f:
  	return err;
  }
  