Пример #1
0
int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
	     struct ipv6_txoptions *opt)
{
	struct ipv6_pinfo * np = sk ? &sk->net_pinfo.af_inet6 : NULL;
	struct in6_addr *first_hop = fl->nl_u.ip6_u.daddr;
	struct dst_entry *dst = skb->dst;
	struct ipv6hdr *hdr;
	u8  proto = fl->proto;
	int seg_len = skb->len;
	int hlimit;

	if (opt) {
		int head_room;

		/* First: exthdrs may take lots of space (~8K for now)
		   MAX_HEADER is not enough.
		 */
		head_room = opt->opt_nflen + opt->opt_flen;
		seg_len += head_room;
		head_room += sizeof(struct ipv6hdr) + ((dst->dev->hard_header_len + 15)&~15);

		if (skb_headroom(skb) < head_room) {
			struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
			kfree_skb(skb);
			skb = skb2;
			if (skb == NULL)
				return -ENOBUFS;
			if (sk)
				skb_set_owner_w(skb, sk);
		}
		if (opt->opt_flen)
			ipv6_push_frag_opts(skb, opt, &proto);
		if (opt->opt_nflen)
			ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
	}

	hdr = skb->nh.ipv6h = (struct ipv6hdr*)skb_push(skb, sizeof(struct ipv6hdr));

	/*
	 *	Fill in the IPv6 header
	 */

	*(u32*)hdr = htonl(0x60000000) | fl->fl6_flowlabel;
	hlimit = -1;
	if (np)
		hlimit = np->hop_limit;
	if (hlimit < 0)
		hlimit = ((struct rt6_info*)dst)->rt6i_hoplimit;

	hdr->payload_len = htons(seg_len);
	hdr->nexthdr = proto;
	hdr->hop_limit = hlimit;

	ipv6_addr_copy(&hdr->saddr, fl->nl_u.ip6_u.saddr);
	ipv6_addr_copy(&hdr->daddr, first_hop);

	if (skb->len <= dst->pmtu) {
		IP6_INC_STATS(Ip6OutRequests);
		return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, ip6_maybe_reroute);
	}

	if (net_ratelimit())
		printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n");
	skb->dev = dst->dev;
	icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, dst->pmtu, skb->dev);
	kfree_skb(skb);
	return -EMSGSIZE;
}
Пример #2
0
int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb),
		    void *from, int length, int transhdrlen,
		    int hlimit, struct ipv6_txoptions *opt, struct flowi *fl, struct rt6_info *rt,
		    unsigned int flags)
{
	struct inet_sock *inet = inet_sk(sk);
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct sk_buff *skb;
	unsigned int maxfraglen, fragheaderlen;
	int exthdrlen;
	int hh_len;
	int mtu;
	int copy;
	int err;
	int offset = 0;
	int csummode = CHECKSUM_NONE;

	if (flags&MSG_PROBE)
		return 0;
	if (skb_queue_empty(&sk->sk_write_queue)) {
		/*
		 * setup for corking
		 */
		if (opt) {
			if (np->cork.opt == NULL) {
				np->cork.opt = kmalloc(opt->tot_len,
						       sk->sk_allocation);
				if (unlikely(np->cork.opt == NULL))
					return -ENOBUFS;
			} else if (np->cork.opt->tot_len < opt->tot_len) {
				printk(KERN_DEBUG "ip6_append_data: invalid option length\n");
				return -EINVAL;
			}
			memcpy(np->cork.opt, opt, opt->tot_len);
			inet->cork.flags |= IPCORK_OPT;
			/* need source address above miyazawa*/
		}
		dst_hold(&rt->u.dst);
		np->cork.rt = rt;
		inet->cork.fl = *fl;
		np->cork.hop_limit = hlimit;
		inet->cork.fragsize = mtu = dst_mtu(rt->u.dst.path);
		if (dst_allfrag(rt->u.dst.path))
			inet->cork.flags |= IPCORK_ALLFRAG;
		inet->cork.length = 0;
		sk->sk_sndmsg_page = NULL;
		sk->sk_sndmsg_off = 0;
		exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0);
		length += exthdrlen;
		transhdrlen += exthdrlen;
	} else {
		rt = np->cork.rt;
		fl = &inet->cork.fl;
		if (inet->cork.flags & IPCORK_OPT)
			opt = np->cork.opt;
		transhdrlen = 0;
		exthdrlen = 0;
		mtu = inet->cork.fragsize;
	}

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

	fragheaderlen = sizeof(struct ipv6hdr) + (opt ? opt->opt_nflen : 0);
	maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);

	if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
		if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
			ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen);
			return -EMSGSIZE;
		}
	}

	/*
	 * Let's try using as much space as possible.
	 * Use MTU if total length of the message fits into the MTU.
	 * Otherwise, we need to reserve fragment header and
	 * fragment alignment (= 8-15 octects, in total).
	 *
	 * Note that we may need to "move" the data from the tail of
	 * of the buffer to the new fragment when we split 
	 * the message.
	 *
	 * FIXME: It may be fragmented into multiple chunks 
	 *        at once if non-fragmentable extension headers
	 *        are too large.
	 * --yoshfuji 
	 */

	inet->cork.length += length;

	if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
		goto alloc_new_skb;

	while (length > 0) {
		/* Check if the remaining data fits into current packet. */
		copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
		if (copy < length)
			copy = maxfraglen - skb->len;

		if (copy <= 0) {
			char *data;
			unsigned int datalen;
			unsigned int fraglen;
			unsigned int fraggap;
			unsigned int alloclen;
			struct sk_buff *skb_prev;
alloc_new_skb:
			skb_prev = skb;

			/* There's no room in the current skb */
			if (skb_prev)
				fraggap = skb_prev->len - maxfraglen;
			else
				fraggap = 0;

			/*
			 * If remaining data exceeds the mtu,
			 * we know we need more fragment(s).
			 */
			datalen = length + fraggap;
			if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
				datalen = maxfraglen - fragheaderlen;

			fraglen = datalen + fragheaderlen;
			if ((flags & MSG_MORE) &&
			    !(rt->u.dst.dev->features&NETIF_F_SG))
				alloclen = mtu;
			else
				alloclen = datalen + fragheaderlen;

			/*
			 * The last fragment gets additional space at tail.
			 * Note: we overallocate on fragments with MSG_MODE
			 * because we have no idea if we're the last one.
			 */
			if (datalen == length + fraggap)
				alloclen += rt->u.dst.trailer_len;

			/*
			 * We just reserve space for fragment header.
			 * Note: this may be overallocation if the message 
			 * (without MSG_MORE) fits into the MTU.
			 */
			alloclen += sizeof(struct frag_hdr);

			if (transhdrlen) {
				skb = sock_alloc_send_skb(sk,
						alloclen + hh_len,
						(flags & MSG_DONTWAIT), &err);
			} else {
				skb = NULL;
				if (atomic_read(&sk->sk_wmem_alloc) <=
				    2 * sk->sk_sndbuf)
					skb = sock_wmalloc(sk,
							   alloclen + hh_len, 1,
							   sk->sk_allocation);
				if (unlikely(skb == NULL))
					err = -ENOBUFS;
			}
			if (skb == NULL)
				goto error;
			/*
			 *	Fill in the control structures
			 */
			skb->ip_summed = csummode;
			skb->csum = 0;
			/* reserve for fragmentation */
			skb_reserve(skb, hh_len+sizeof(struct frag_hdr));

			/*
			 *	Find where to start putting bytes
			 */
			data = skb_put(skb, fraglen);
			skb->nh.raw = data + exthdrlen;
			data += fragheaderlen;
			skb->h.raw = data + exthdrlen;

			if (fraggap) {
				skb->csum = skb_copy_and_csum_bits(
					skb_prev, maxfraglen,
					data + transhdrlen, fraggap, 0);
				skb_prev->csum = csum_sub(skb_prev->csum,
							  skb->csum);
				data += fraggap;
				skb_trim(skb_prev, maxfraglen);
			}
			copy = datalen - transhdrlen - fraggap;
			if (copy < 0) {
				err = -EINVAL;
				kfree_skb(skb);
				goto error;
			} else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
				err = -EFAULT;
				kfree_skb(skb);
				goto error;
			}

			offset += copy;
			length -= datalen - fraggap;
			transhdrlen = 0;
			exthdrlen = 0;
			csummode = CHECKSUM_NONE;

			/*
			 * Put the packet on the pending queue
			 */
			__skb_queue_tail(&sk->sk_write_queue, skb);
			continue;
		}

		if (copy > length)
			copy = length;

		if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
			unsigned int off;

			off = skb->len;
			if (getfrag(from, skb_put(skb, copy),
						offset, copy, off, skb) < 0) {
				__skb_trim(skb, off);
				err = -EFAULT;
				goto error;
			}
		} else {
			int i = skb_shinfo(skb)->nr_frags;
			skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
			struct page *page = sk->sk_sndmsg_page;
			int off = sk->sk_sndmsg_off;
			unsigned int left;

			if (page && (left = PAGE_SIZE - off) > 0) {
				if (copy >= left)
					copy = left;
				if (page != frag->page) {
					if (i == MAX_SKB_FRAGS) {
						err = -EMSGSIZE;
						goto error;
					}
					get_page(page);
					skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
					frag = &skb_shinfo(skb)->frags[i];
				}
			} else if(i < MAX_SKB_FRAGS) {
				if (copy > PAGE_SIZE)
					copy = PAGE_SIZE;
				page = alloc_pages(sk->sk_allocation, 0);
				if (page == NULL) {
					err = -ENOMEM;
					goto error;
				}
				sk->sk_sndmsg_page = page;
				sk->sk_sndmsg_off = 0;

				skb_fill_page_desc(skb, i, page, 0, 0);
				frag = &skb_shinfo(skb)->frags[i];
				skb->truesize += PAGE_SIZE;
				atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
			} else {
				err = -EMSGSIZE;
				goto error;
			}
			if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
				err = -EFAULT;
				goto error;
			}
			sk->sk_sndmsg_off += copy;
			frag->size += copy;
			skb->len += copy;
			skb->data_len += copy;
		}
		offset += copy;
		length -= copy;
	}
	return 0;
error:
	inet->cork.length -= length;
	IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
	return err;
}
Пример #3
0
int ip6_forward(struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	struct ipv6hdr *hdr = ipv6_hdr(skb);
	struct inet6_skb_parm *opt = IP6CB(skb);
	struct net *net = dev_net(dst->dev);
	u32 mtu;

	if (net->ipv6.devconf_all->forwarding == 0)
		goto error;

	if (skb_warn_if_lro(skb))
		goto drop;

	if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
		IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
		goto drop;
	}

	if (skb->pkt_type != PACKET_HOST)
		goto drop;

	skb_forward_csum(skb);

	/*
	 *	We DO NOT make any processing on
	 *	RA packets, pushing them to user level AS IS
	 *	without ane WARRANTY that application will be able
	 *	to interpret them. The reason is that we
	 *	cannot make anything clever here.
	 *
	 *	We are not end-node, so that if packet contains
	 *	AH/ESP, we cannot make anything.
	 *	Defragmentation also would be mistake, RA packets
	 *	cannot be fragmented, because there is no warranty
	 *	that different fragments will go along one path. --ANK
	 */
	if (opt->ra) {
		u8 *ptr = skb_network_header(skb) + opt->ra;
		if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
			return 0;
	}

	/*
	 *	check and decrement ttl
	 */
	if (hdr->hop_limit <= 1) {
		/* Force OUTPUT device used as source address */
		skb->dev = dst->dev;
		icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0);
		IP6_INC_STATS_BH(net,
				 ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);

		kfree_skb(skb);
		return -ETIMEDOUT;
	}

	/* XXX: idev->cnf.proxy_ndp? */
	if ((net->ipv6.devconf_all->proxy_ndp == 1 &&
	    pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0))
	    || net->ipv6.devconf_all->proxy_ndp >= 2) {
		int proxied = ip6_forward_proxy_check(skb);
		if (proxied > 0)
			return ip6_input(skb);
		else if (proxied < 0) {
			IP6_INC_STATS(net, ip6_dst_idev(dst),
				      IPSTATS_MIB_INDISCARDS);
			goto drop;
		}
	}

	if (!xfrm6_route_forward(skb)) {
		IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
		goto drop;
	}
	dst = skb_dst(skb);

	/* IPv6 specs say nothing about it, but it is clear that we cannot
	   send redirects to source routed frames.
	   We don't send redirects to frames decapsulated from IPsec.
	 */
	if (skb->dev == dst->dev && opt->srcrt == 0 && !skb_sec_path(skb)) {
		struct in6_addr *target = NULL;
		struct rt6_info *rt;

		/*
		 *	incoming and outgoing devices are the same
		 *	send a redirect.
		 */

		rt = (struct rt6_info *) dst;
		if (rt->rt6i_flags & RTF_GATEWAY)
			target = &rt->rt6i_gateway;
		else
			target = &hdr->daddr;

		if (!rt->rt6i_peer)
			rt6_bind_peer(rt, 1);

		/* Limit redirects both by destination (here)
		   and by source (inside ndisc_send_redirect)
		 */
		if (inet_peer_xrlim_allow(rt->rt6i_peer, 1*HZ))
			ndisc_send_redirect(skb, target);
	} else {
		int addrtype = ipv6_addr_type(&hdr->saddr);

		/* This check is security critical. */
		if (addrtype == IPV6_ADDR_ANY ||
		    addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK))
			goto error;
		if (addrtype & IPV6_ADDR_LINKLOCAL) {
			icmpv6_send(skb, ICMPV6_DEST_UNREACH,
				    ICMPV6_NOT_NEIGHBOUR, 0);
			goto error;
		}
	}

	mtu = dst_mtu(dst);
	if (mtu < IPV6_MIN_MTU)
		mtu = IPV6_MIN_MTU;

	if (skb->len > mtu && !skb_is_gso(skb)) {
		/* Again, force OUTPUT device used as source address */
		skb->dev = dst->dev;
		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
		IP6_INC_STATS_BH(net,
				 ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS);
		IP6_INC_STATS_BH(net,
				 ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS);
		kfree_skb(skb);
		return -EMSGSIZE;
	}

	if (skb_cow(skb, dst->dev->hard_header_len)) {
		IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS);
		goto drop;
	}

	hdr = ipv6_hdr(skb);

	/* Mangling hops number delayed to point after skb COW */

	hdr->hop_limit--;

	IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
	return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, skb, skb->dev, dst->dev,
		       ip6_forward_finish);

error:
	IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
drop:
	kfree_skb(skb);
	return -EINVAL;
}
Пример #4
0
static int __ip6_append_data(struct sock *sk,
			     struct flowi6 *fl6,
			     struct sk_buff_head *queue,
			     struct inet_cork *cork,
			     struct inet6_cork *v6_cork,
			     struct page_frag *pfrag,
			     int getfrag(void *from, char *to, int offset,
					 int len, int odd, struct sk_buff *skb),
			     void *from, int length, int transhdrlen,
			     unsigned int flags, struct ipcm6_cookie *ipc6,
			     const struct sockcm_cookie *sockc)
{
	struct sk_buff *skb, *skb_prev = NULL;
	unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu;
	int exthdrlen = 0;
	int dst_exthdrlen = 0;
	int hh_len;
	int copy;
	int err;
	int offset = 0;
	__u8 tx_flags = 0;
	u32 tskey = 0;
	struct rt6_info *rt = (struct rt6_info *)cork->dst;
	struct ipv6_txoptions *opt = v6_cork->opt;
	int csummode = CHECKSUM_NONE;
	unsigned int maxnonfragsize, headersize;

	skb = skb_peek_tail(queue);
	if (!skb) {
		exthdrlen = opt ? opt->opt_flen : 0;
		dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len;
	}

	mtu = cork->fragsize;
	orig_mtu = mtu;

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

	fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
			(opt ? opt->opt_nflen : 0);
	maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen -
		     sizeof(struct frag_hdr);

	headersize = sizeof(struct ipv6hdr) +
		     (opt ? opt->opt_flen + opt->opt_nflen : 0) +
		     (dst_allfrag(&rt->dst) ?
		      sizeof(struct frag_hdr) : 0) +
		     rt->rt6i_nfheader_len;

	if (cork->length + length > mtu - headersize && ipc6->dontfrag &&
	    (sk->sk_protocol == IPPROTO_UDP ||
	     sk->sk_protocol == IPPROTO_RAW)) {
		ipv6_local_rxpmtu(sk, fl6, mtu - headersize +
				sizeof(struct ipv6hdr));
		goto emsgsize;
	}

	if (ip6_sk_ignore_df(sk))
		maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN;
	else
		maxnonfragsize = mtu;

	if (cork->length + length > maxnonfragsize - headersize) {
emsgsize:
		ipv6_local_error(sk, EMSGSIZE, fl6,
				 mtu - headersize +
				 sizeof(struct ipv6hdr));
		return -EMSGSIZE;
	}

	/* CHECKSUM_PARTIAL only with no extension headers and when
	 * we are not going to fragment
	 */
	if (transhdrlen && sk->sk_protocol == IPPROTO_UDP &&
	    headersize == sizeof(struct ipv6hdr) &&
	    length < mtu - headersize &&
	    !(flags & MSG_MORE) &&
	    rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM))
		csummode = CHECKSUM_PARTIAL;

	if (sk->sk_type == SOCK_DGRAM || sk->sk_type == SOCK_RAW) {
		sock_tx_timestamp(sk, sockc->tsflags, &tx_flags);
		if (tx_flags & SKBTX_ANY_SW_TSTAMP &&
		    sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)
			tskey = sk->sk_tskey++;
	}

	/*
	 * Let's try using as much space as possible.
	 * Use MTU if total length of the message fits into the MTU.
	 * Otherwise, we need to reserve fragment header and
	 * fragment alignment (= 8-15 octects, in total).
	 *
	 * Note that we may need to "move" the data from the tail of
	 * of the buffer to the new fragment when we split
	 * the message.
	 *
	 * FIXME: It may be fragmented into multiple chunks
	 *        at once if non-fragmentable extension headers
	 *        are too large.
	 * --yoshfuji
	 */

	cork->length += length;
	if (((length > mtu) ||
	     (skb && skb_is_gso(skb))) &&
	    (sk->sk_protocol == IPPROTO_UDP) &&
	    (rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len &&
	    (sk->sk_type == SOCK_DGRAM) && !udp_get_no_check6_tx(sk)) {
		err = ip6_ufo_append_data(sk, queue, getfrag, from, length,
					  hh_len, fragheaderlen, exthdrlen,
					  transhdrlen, mtu, flags, fl6);
		if (err)
			goto error;
		return 0;
	}

	if (!skb)
		goto alloc_new_skb;

	while (length > 0) {
		/* Check if the remaining data fits into current packet. */
		copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
		if (copy < length)
			copy = maxfraglen - skb->len;

		if (copy <= 0) {
			char *data;
			unsigned int datalen;
			unsigned int fraglen;
			unsigned int fraggap;
			unsigned int alloclen;
alloc_new_skb:
			/* There's no room in the current skb */
			if (skb)
				fraggap = skb->len - maxfraglen;
			else
				fraggap = 0;
			/* update mtu and maxfraglen if necessary */
			if (!skb || !skb_prev)
				ip6_append_data_mtu(&mtu, &maxfraglen,
						    fragheaderlen, skb, rt,
						    orig_mtu);

			skb_prev = skb;

			/*
			 * If remaining data exceeds the mtu,
			 * we know we need more fragment(s).
			 */
			datalen = length + fraggap;

			if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
				datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
			if ((flags & MSG_MORE) &&
			    !(rt->dst.dev->features&NETIF_F_SG))
				alloclen = mtu;
			else
				alloclen = datalen + fragheaderlen;

			alloclen += dst_exthdrlen;

			if (datalen != length + fraggap) {
				/*
				 * this is not the last fragment, the trailer
				 * space is regarded as data space.
				 */
				datalen += rt->dst.trailer_len;
			}

			alloclen += rt->dst.trailer_len;
			fraglen = datalen + fragheaderlen;

			/*
			 * We just reserve space for fragment header.
			 * Note: this may be overallocation if the message
			 * (without MSG_MORE) fits into the MTU.
			 */
			alloclen += sizeof(struct frag_hdr);

			if (transhdrlen) {
				skb = sock_alloc_send_skb(sk,
						alloclen + hh_len,
						(flags & MSG_DONTWAIT), &err);
			} else {
				skb = NULL;
				if (atomic_read(&sk->sk_wmem_alloc) <=
				    2 * sk->sk_sndbuf)
					skb = sock_wmalloc(sk,
							   alloclen + hh_len, 1,
							   sk->sk_allocation);
				if (unlikely(!skb))
					err = -ENOBUFS;
			}
			if (!skb)
				goto error;
			/*
			 *	Fill in the control structures
			 */
			skb->protocol = htons(ETH_P_IPV6);
			skb->ip_summed = csummode;
			skb->csum = 0;
			/* reserve for fragmentation and ipsec header */
			skb_reserve(skb, hh_len + sizeof(struct frag_hdr) +
				    dst_exthdrlen);

			/* Only the initial fragment is time stamped */
			skb_shinfo(skb)->tx_flags = tx_flags;
			tx_flags = 0;
			skb_shinfo(skb)->tskey = tskey;
			tskey = 0;

			/*
			 *	Find where to start putting bytes
			 */
			data = skb_put(skb, fraglen);
			skb_set_network_header(skb, exthdrlen);
			data += fragheaderlen;
			skb->transport_header = (skb->network_header +
						 fragheaderlen);
			if (fraggap) {
				skb->csum = skb_copy_and_csum_bits(
					skb_prev, maxfraglen,
					data + transhdrlen, fraggap, 0);
				skb_prev->csum = csum_sub(skb_prev->csum,
							  skb->csum);
				data += fraggap;
				pskb_trim_unique(skb_prev, maxfraglen);
			}
			copy = datalen - transhdrlen - fraggap;

			if (copy < 0) {
				err = -EINVAL;
				kfree_skb(skb);
				goto error;
			} else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
				err = -EFAULT;
				kfree_skb(skb);
				goto error;
			}

			offset += copy;
			length -= datalen - fraggap;
			transhdrlen = 0;
			exthdrlen = 0;
			dst_exthdrlen = 0;

			/*
			 * Put the packet on the pending queue
			 */
			__skb_queue_tail(queue, skb);
			continue;
		}

		if (copy > length)
			copy = length;

		if (!(rt->dst.dev->features&NETIF_F_SG)) {
			unsigned int off;

			off = skb->len;
			if (getfrag(from, skb_put(skb, copy),
						offset, copy, off, skb) < 0) {
				__skb_trim(skb, off);
				err = -EFAULT;
				goto error;
			}
		} else {
			int i = skb_shinfo(skb)->nr_frags;

			err = -ENOMEM;
			if (!sk_page_frag_refill(sk, pfrag))
				goto error;

			if (!skb_can_coalesce(skb, i, pfrag->page,
					      pfrag->offset)) {
				err = -EMSGSIZE;
				if (i == MAX_SKB_FRAGS)
					goto error;

				__skb_fill_page_desc(skb, i, pfrag->page,
						     pfrag->offset, 0);
				skb_shinfo(skb)->nr_frags = ++i;
				get_page(pfrag->page);
			}
			copy = min_t(int, copy, pfrag->size - pfrag->offset);
			if (getfrag(from,
				    page_address(pfrag->page) + pfrag->offset,
				    offset, copy, skb->len, skb) < 0)
				goto error_efault;

			pfrag->offset += copy;
			skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
			skb->len += copy;
			skb->data_len += copy;
			skb->truesize += copy;
			atomic_add(copy, &sk->sk_wmem_alloc);
		}
		offset += copy;
		length -= copy;
	}

	return 0;

error_efault:
	err = -EFAULT;
error:
	cork->length -= length;
	IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
	return err;
}
Пример #5
0
static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
			   struct frag_hdr *fhdr, int nhoff)
{
	struct sk_buff *prev, *next;
	struct net_device *dev;
	int offset, end;
	struct net *net = dev_net(skb->dst->dev);

	if (fq->q.last_in & INET_FRAG_COMPLETE)
		goto err;

	offset = ntohs(fhdr->frag_off) & ~0x7;
	end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
			((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));

	if ((unsigned int)end > IPV6_MAXPLEN) {
		IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst),
				 IPSTATS_MIB_INHDRERRORS);
		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
				  ((u8 *)&fhdr->frag_off -
				   skb_network_header(skb)));
		return -1;
	}

	if (skb->ip_summed == CHECKSUM_COMPLETE) {
		const unsigned char *nh = skb_network_header(skb);
		skb->csum = csum_sub(skb->csum,
				     csum_partial(nh, (u8 *)(fhdr + 1) - nh,
						  0));
	}

	/* Is this the final fragment? */
	if (!(fhdr->frag_off & htons(IP6_MF))) {
		/* If we already have some bits beyond end
		 * or have different end, the segment is corrupted.
		 */
		if (end < fq->q.len ||
		    ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len))
			goto err;
		fq->q.last_in |= INET_FRAG_LAST_IN;
		fq->q.len = end;
	} else {
		/* Check if the fragment is rounded to 8 bytes.
		 * Required by the RFC.
		 */
		if (end & 0x7) {
			/* RFC2460 says always send parameter problem in
			 * this case. -DaveM
			 */
			IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst),
					 IPSTATS_MIB_INHDRERRORS);
			icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
					  offsetof(struct ipv6hdr, payload_len));
			return -1;
		}
		if (end > fq->q.len) {
			/* Some bits beyond end -> corruption. */
			if (fq->q.last_in & INET_FRAG_LAST_IN)
				goto err;
			fq->q.len = end;
		}
	}

	if (end == offset)
		goto err;

	/* Point into the IP datagram 'data' part. */
	if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
		goto err;

	if (pskb_trim_rcsum(skb, end - offset))
		goto err;

	/* Find out which fragments are in front and at the back of us
	 * in the chain of fragments so far.  We must know where to put
	 * this fragment, right?
	 */
	prev = NULL;
	for(next = fq->q.fragments; next != NULL; next = next->next) {
		if (FRAG6_CB(next)->offset >= offset)
			break;	/* bingo! */
		prev = next;
	}

	/* We found where to put this one.  Check for overlap with
	 * preceding fragment, and, if needed, align things so that
	 * any overlaps are eliminated.
	 */
	if (prev) {
		int i = (FRAG6_CB(prev)->offset + prev->len) - offset;

		if (i > 0) {
			offset += i;
			if (end <= offset)
				goto err;
			if (!pskb_pull(skb, i))
				goto err;
			if (skb->ip_summed != CHECKSUM_UNNECESSARY)
				skb->ip_summed = CHECKSUM_NONE;
		}
	}

	/* Look for overlap with succeeding segments.
	 * If we can merge fragments, do it.
	 */
	while (next && FRAG6_CB(next)->offset < end) {
		int i = end - FRAG6_CB(next)->offset; /* overlap is 'i' bytes */

		if (i < next->len) {
			/* Eat head of the next overlapped fragment
			 * and leave the loop. The next ones cannot overlap.
			 */
			if (!pskb_pull(next, i))
				goto err;
			FRAG6_CB(next)->offset += i;	/* next fragment */
			fq->q.meat -= i;
			if (next->ip_summed != CHECKSUM_UNNECESSARY)
				next->ip_summed = CHECKSUM_NONE;
			break;
		} else {
			struct sk_buff *free_it = next;

			/* Old fragment is completely overridden with
			 * new one drop it.
			 */
			next = next->next;

			if (prev)
				prev->next = next;
			else
				fq->q.fragments = next;

			fq->q.meat -= free_it->len;
			frag_kfree_skb(fq->q.net, free_it, NULL);
		}
	}

	FRAG6_CB(skb)->offset = offset;

	/* Insert this fragment in the chain of fragments. */
	skb->next = next;
	if (prev)
		prev->next = skb;
	else
		fq->q.fragments = skb;

	dev = skb->dev;
	if (dev) {
		fq->iif = dev->ifindex;
		skb->dev = NULL;
	}
	fq->q.stamp = skb->tstamp;
	fq->q.meat += skb->len;
	atomic_add(skb->truesize, &fq->q.net->mem);

	/* The first fragment.
	 * nhoffset is obtained from the first fragment, of course.
	 */
	if (offset == 0) {
		fq->nhoffset = nhoff;
		fq->q.last_in |= INET_FRAG_FIRST_IN;
	}

	if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
	    fq->q.meat == fq->q.len)
		return ip6_frag_reasm(fq, prev, dev);

	write_lock(&ip6_frags.lock);
	list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list);
	write_unlock(&ip6_frags.lock);
	return -1;

err:
	IP6_INC_STATS(net, ip6_dst_idev(skb->dst),
		      IPSTATS_MIB_REASMFAILS);
	kfree_skb(skb);
	return -1;
}
Пример #6
0
int ip6_push_pending_frames(struct sock *sk)
{
	struct sk_buff *skb, *tmp_skb;
	struct sk_buff **tail_skb;
	struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
	struct inet_sock *inet = inet_sk(sk);
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct net *net = sock_net(sk);
	struct ipv6hdr *hdr;
	struct ipv6_txoptions *opt = np->cork.opt;
	struct rt6_info *rt = (struct rt6_info *)inet->cork.base.dst;
	struct flowi6 *fl6 = &inet->cork.fl.u.ip6;
	unsigned char proto = fl6->flowi6_proto;
	int err = 0;

	if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
		goto out;
	tail_skb = &(skb_shinfo(skb)->frag_list);

	/* move skb->data to ip header from ext header */
	if (skb->data < skb_network_header(skb))
		__skb_pull(skb, skb_network_offset(skb));
	while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
		__skb_pull(tmp_skb, skb_network_header_len(skb));
		*tail_skb = tmp_skb;
		tail_skb = &(tmp_skb->next);
		skb->len += tmp_skb->len;
		skb->data_len += tmp_skb->len;
		skb->truesize += tmp_skb->truesize;
		tmp_skb->destructor = NULL;
		tmp_skb->sk = NULL;
	}

	/* Allow local fragmentation. */
	if (np->pmtudisc < IPV6_PMTUDISC_DO)
		skb->local_df = 1;

	*final_dst = fl6->daddr;
	__skb_pull(skb, skb_network_header_len(skb));
	if (opt && opt->opt_flen)
		ipv6_push_frag_opts(skb, opt, &proto);
	if (opt && opt->opt_nflen)
		ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);

	skb_push(skb, sizeof(struct ipv6hdr));
	skb_reset_network_header(skb);
	hdr = ipv6_hdr(skb);

	*(__be32*)hdr = fl6->flowlabel |
		     htonl(0x60000000 | ((int)np->cork.tclass << 20));

	hdr->hop_limit = np->cork.hop_limit;
	hdr->nexthdr = proto;
	hdr->saddr = fl6->saddr;
	hdr->daddr = *final_dst;

	skb->priority = sk->sk_priority;
	skb->mark = sk->sk_mark;

	skb_dst_set(skb, dst_clone(&rt->dst));
	IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);
	if (proto == IPPROTO_ICMPV6) {
		struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));

		ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type);
		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
	}

	err = ip6_local_out(skb);
	if (err) {
		if (err > 0)
			err = net_xmit_errno(err);
		if (err)
			goto error;
	}

out:
	ip6_cork_release(inet, np);
	return err;
error:
	IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
	goto out;
}
Пример #7
0
int ip6_build_xmit(struct sock *sk, inet_getfrag_t getfrag, const void *data,
		   struct flowi *fl, unsigned length,
		   struct ipv6_txoptions *opt, int hlimit, int flags)
{
	struct ipv6_pinfo *np = &sk->net_pinfo.af_inet6;
	struct in6_addr final_dst_buf, *final_dst = NULL;
	struct dst_entry *dst;
	int err = 0;
	unsigned int pktlength, jumbolen, mtu;

	if (opt && opt->srcrt) {
		struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
		ipv6_addr_copy(&final_dst_buf, &fl->fl6_dst);
		final_dst = &final_dst_buf;
		ipv6_addr_copy(&fl->fl6_dst, rt0->addr);
	}

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

	dst = __sk_dst_check(sk, np->dst_cookie);
	if (dst) {
		struct rt6_info *rt = (struct rt6_info*)dst;

			/* Yes, checking route validity in not connected
			   case is not very simple. Take into account,
			   that we do not support routing by source, TOS,
			   and MSG_DONTROUTE 		--ANK (980726)

			   1. If route was host route, check that
			      cached destination is current.
			      If it is network route, we still may
			      check its validity using saved pointer
			      to the last used address: daddr_cache.
			      We do not want to save whole address now,
			      (because main consumer of this service
			       is tcp, which has not this problem),
			      so that the last trick works only on connected
			      sockets.
			   2. oif also should be the same.
			 */

		if (((rt->rt6i_dst.plen != 128 ||
		      ipv6_addr_cmp(&fl->fl6_dst, &rt->rt6i_dst.addr))
		     && (np->daddr_cache == NULL ||
			 ipv6_addr_cmp(&fl->fl6_dst, np->daddr_cache)))
		    || (fl->oif && fl->oif != dst->dev->ifindex)) {
			dst = NULL;
		} else
			dst_hold(dst);
	}

	if (dst == NULL)
		dst = ip6_route_output(sk, fl);

	if (dst->error) {
		IP6_INC_STATS(Ip6OutNoRoutes);
		dst_release(dst);
		return -ENETUNREACH;
	}

	if (ipv6_addr_any(&fl->fl6_src)) {
		err = ipv6_get_saddr(dst, &fl->fl6_dst, &fl->fl6_src);

		if (err) {
#if IP6_DEBUG >= 2
			printk(KERN_DEBUG "ip6_build_xmit: "
			       "no available source address\n");
#endif
			goto out;
		}
	}
	pktlength = length;

        if (dst) {
		if ((err = xfrm_lookup(&dst, fl, sk, 0)) < 0) {
			dst_release(dst);	
			return -ENETUNREACH;
		}
        }

	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);
	}

	jumbolen = 0;

	if (!sk->protinfo.af_inet.hdrincl) {
		pktlength += sizeof(struct ipv6hdr);
		if (opt)
			pktlength += opt->opt_flen + opt->opt_nflen;

		if (pktlength > sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
			/* Jumbo datagram.
			   It is assumed, that in the case of hdrincl
			   jumbo option is supplied by user.
			 */
			pktlength += 8;
			jumbolen = pktlength - sizeof(struct ipv6hdr);
		}
	}

	mtu = dst_pmtu(dst);
	if (np->frag_size < mtu) {
		if (np->frag_size)
			mtu = np->frag_size;
		else if (np->pmtudisc == IPV6_PMTUDISC_DONT)
			mtu = IPV6_MIN_MTU;
	}

	/* Critical arithmetic overflow check.
	   FIXME: may gcc optimize it out? --ANK (980726)
	 */
	if (pktlength < length) {
		ipv6_local_error(sk, EMSGSIZE, fl, mtu);
		err = -EMSGSIZE;
		goto out;
	}

	if (flags&MSG_CONFIRM)
		dst_confirm(dst);

	if (pktlength <= mtu) {
		struct sk_buff *skb;
		struct ipv6hdr *hdr;
		struct net_device *dev = dst->dev;

		err = 0;
		if (flags&MSG_PROBE)
			goto out;
		/* alloc skb with mtu as we do in the IPv4 stack for IPsec */
		skb = sock_alloc_send_skb(sk, mtu + LL_RESERVED_SPACE(dev),
					  flags & MSG_DONTWAIT, &err);

		if (skb == NULL) {
			IP6_INC_STATS(Ip6OutDiscards);
			goto out;
		}

		skb->dst = dst_clone(dst);

		skb_reserve(skb, (dev->hard_header_len + 15) & ~15);

		hdr = (struct ipv6hdr *) skb->tail;
		skb->nh.ipv6h = hdr;

		if (!sk->protinfo.af_inet.hdrincl) {
			ip6_bld_1(sk, skb, fl, hlimit,
				  jumbolen ? sizeof(struct ipv6hdr) : pktlength);

			if (opt || jumbolen) {
				u8 *prev_hdr = &hdr->nexthdr;
				prev_hdr = ipv6_build_nfrag_opts(skb, prev_hdr, opt, final_dst, jumbolen);
				if (opt && opt->opt_flen)
					ipv6_build_frag_opts(skb, prev_hdr, opt);
			}
		}

		skb_put(skb, length);
		err = getfrag(data, &hdr->saddr,
			      ((char *) hdr) + (pktlength - length),
			      0, length);
		if (!opt || !opt->dst1opt)
			skb->h.raw = ((char *) hdr) + (pktlength - length);

		if (!err) {
			IP6_INC_STATS(Ip6OutRequests);
			err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, ip6_maybe_reroute);
		} else {
			err = -EFAULT;
			kfree_skb(skb);
		}
	} else {
		if (sk->protinfo.af_inet.hdrincl || jumbolen ||
		    np->pmtudisc == IPV6_PMTUDISC_DO) {
			ipv6_local_error(sk, EMSGSIZE, fl, mtu);
			err = -EMSGSIZE;
			goto out;
		}

		err = ip6_frag_xmit(sk, getfrag, data, dst, fl, opt, final_dst, hlimit,
				    flags, length, mtu);
	}

	/*
	 *	cleanup
	 */
out:
	ip6_dst_store(sk, dst,
		      !ipv6_addr_cmp(&fl->fl6_dst, &np->daddr) ?
		      &np->daddr : NULL);
	if (err > 0)
		err = np->recverr ? net_xmit_errno(err) : 0;
	return err;
}
Пример #8
0
static int ipv6_frag_rcv(struct sk_buff *skb)
{
	struct frag_hdr *fhdr;
	struct frag_queue *fq;
	const struct ipv6hdr *hdr = ipv6_hdr(skb);
	struct net *net = dev_net(skb_dst(skb)->dev);
	int evicted;

	if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED)
		goto fail_hdr;

	IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS);

	/* Jumbo payload inhibits frag. header */
	if (hdr->payload_len==0)
		goto fail_hdr;

	if (!pskb_may_pull(skb, (skb_transport_offset(skb) +
				 sizeof(struct frag_hdr))))
		goto fail_hdr;

	hdr = ipv6_hdr(skb);
	fhdr = (struct frag_hdr *)skb_transport_header(skb);

	if (!(fhdr->frag_off & htons(0xFFF9))) {
		/* It is not a fragmented frame */
		skb->transport_header += sizeof(struct frag_hdr);
		IP6_INC_STATS_BH(net,
				 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS);

		IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb);
		IP6CB(skb)->flags |= IP6SKB_FRAGMENTED;
		return 1;
	}

	evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags, false);
	if (evicted)
		IP6_ADD_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
				 IPSTATS_MIB_REASMFAILS, evicted);

	fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr,
		     ip6_frag_ecn(hdr));
	if (fq != NULL) {
		int ret;

		spin_lock(&fq->q.lock);

		ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);

		spin_unlock(&fq->q.lock);
		inet_frag_put(&fq->q, &ip6_frags);
		return ret;
	}

	IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS);
	kfree_skb(skb);
	return -1;

fail_hdr:
	IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS);
	icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb));
	return -1;
}
Пример #9
0
int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb),
		    void *from, int length, int transhdrlen,
		    int hlimit, struct ipv6_txoptions *opt, struct flowi *fl, struct rt6_info *rt,
		    unsigned int flags)
{
	struct inet_opt *inet = inet_sk(sk);
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct sk_buff *skb;
	unsigned int maxfraglen, fragheaderlen;
	int exthdrlen;
	int hh_len;
	int mtu;
	int copy = 0;
	int err;
	int offset = 0;
	int csummode = CHECKSUM_NONE;

	if (flags&MSG_PROBE)
		return 0;
	if (skb_queue_empty(&sk->write_queue)) {
		/*
		 * setup for corking
		 */
		if (opt) {
			if (np->cork.opt == NULL)
				np->cork.opt = kmalloc(opt->tot_len, sk->allocation);
			memcpy(np->cork.opt, opt, opt->tot_len);
			inet->cork.flags |= IPCORK_OPT;
			/* need source address above miyazawa*/
		}
		dst_hold(&rt->u.dst);
		np->cork.rt = rt;
		np->cork.fl = fl;
		np->cork.hop_limit = hlimit;
		inet->cork.fragsize = mtu = dst_pmtu(&rt->u.dst);
		inet->cork.length = 0;
		inet->sndmsg_page = NULL;
		inet->sndmsg_off = 0;
		exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0);
		length += exthdrlen;
		transhdrlen += exthdrlen;
	} else {
		rt = np->cork.rt;
		if (inet->cork.flags & IPCORK_OPT)
			opt = np->cork.opt;
		transhdrlen = 0;
		exthdrlen = 0;
		mtu = inet->cork.fragsize;
	}

	hh_len = (rt->u.dst.dev->hard_header_len&~15) + 16;

	fragheaderlen = sizeof(struct ipv6hdr) + (opt ? opt->opt_nflen : 0);
	maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);

	if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
		if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
			ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen);
			return -EMSGSIZE;
		}
	}

	inet->cork.length += length;

	if ((skb = skb_peek_tail(&sk->write_queue)) == NULL)
		goto alloc_new_skb;

	while (length > 0) {
		if ((copy = maxfraglen - skb->len) <= 0) {
			char *data;
			unsigned int datalen;
			unsigned int fraglen;
			unsigned int alloclen;
			BUG_TRAP(copy == 0);
alloc_new_skb:
			datalen = maxfraglen - fragheaderlen;
			if (datalen > length)
				datalen = length;
			fraglen = datalen + fragheaderlen;
			if ((flags & MSG_MORE) &&
			    !(rt->u.dst.dev->features&NETIF_F_SG))
				alloclen = maxfraglen;
			else
				alloclen = fraglen;
			alloclen += sizeof(struct frag_hdr);
			if (transhdrlen) {
				skb = sock_alloc_send_skb(sk,
						alloclen + hh_len + 15,
						(flags & MSG_DONTWAIT), &err);
			} else {
				skb = NULL;
				if (atomic_read(&sk->wmem_alloc) <= 2*sk->sndbuf)
					skb = sock_wmalloc(sk,
							   alloclen + hh_len + 15, 1,
							   sk->allocation);
				if (unlikely(skb == NULL))
					err = -ENOBUFS;
			}
			if (skb == NULL)
				goto error;
			/*
			 *	Fill in the control structures
			 */
			skb->ip_summed = csummode;
			skb->csum = 0;
			/* reserve 8 byte for fragmentation */
			skb_reserve(skb, hh_len+sizeof(struct frag_hdr));

			/*
			 *	Find where to start putting bytes
			 */
			data = skb_put(skb, fraglen);
			skb->nh.raw = data + exthdrlen;
			data += fragheaderlen;
			skb->h.raw = data + exthdrlen;
			copy = datalen - transhdrlen;
			if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, 0, skb) < 0) {
				err = -EFAULT;
				kfree_skb(skb);
				goto error;
			}

			offset += copy;
			length -= datalen;
			transhdrlen = 0;
			exthdrlen = 0;
			csummode = CHECKSUM_NONE;

			/*
			 * Put the packet on the pending queue
			 */
			__skb_queue_tail(&sk->write_queue, skb);
			continue;
		}

		if (copy > length)
			copy = length;

		if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
			unsigned int off;

			off = skb->len;
			if (getfrag(from, skb_put(skb, copy),
						offset, copy, off, skb) < 0) {
				__skb_trim(skb, off);
				err = -EFAULT;
				goto error;
			}
		} else {
			int i = skb_shinfo(skb)->nr_frags;
			skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
			struct page *page = inet->sndmsg_page;
			int off = inet->sndmsg_off;
			unsigned int left;

			if (page && (left = PAGE_SIZE - off) > 0) {
				if (copy >= left)
					copy = left;
				if (page != frag->page) {
					if (i == MAX_SKB_FRAGS) {
						err = -EMSGSIZE;
						goto error;
					}
					get_page(page);
					skb_fill_page_desc(skb, i, page, inet->sndmsg_off, 0);
					frag = &skb_shinfo(skb)->frags[i];
				}
			} else if(i < MAX_SKB_FRAGS) {
				if (copy > PAGE_SIZE)
					copy = PAGE_SIZE;
				page = alloc_pages(sk->allocation, 0);
				if (page == NULL) {
					err = -ENOMEM;
					goto error;
				}
				inet->sndmsg_page = page;
				inet->sndmsg_off = 0;

				skb_fill_page_desc(skb, i, page, 0, 0);
				frag = &skb_shinfo(skb)->frags[i];
				skb->truesize += PAGE_SIZE;
				atomic_add(PAGE_SIZE, &sk->wmem_alloc);
			} else {
				err = -EMSGSIZE;
				goto error;
			}
			if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
				err = -EFAULT;
				goto error;
			}
			inet->sndmsg_off += copy;
			frag->size += copy;
			skb->len += copy;
			skb->data_len += copy;
		}
		offset += copy;
		length -= copy;
	}
	return 0;
error:
	inet->cork.length -= length;
	IP6_INC_STATS(Ip6OutDiscards);
	return err;
}
Пример #10
0
static int ip6_frag_xmit(struct sock *sk, inet_getfrag_t getfrag,
			 const void *data, struct dst_entry *dst,
			 struct flowi *fl, struct ipv6_txoptions *opt,
			 struct in6_addr *final_dst,
			 int hlimit, int flags, unsigned length, int mtu)
{
	struct ipv6hdr *hdr;
	struct sk_buff *last_skb;
	u8 *prev_hdr;
	int unfrag_len;
	int frag_len;
	int last_len;
	int nfrags;
	int fhdr_dist;
	int frag_off;
	int data_off;
	int err;

	/*
	 *	Fragmentation
	 *
	 *	Extension header order:
	 *	Hop-by-hop -> Dest0 -> Routing -> Fragment -> Auth -> Dest1 -> rest (...)
	 *	
	 *	We must build the non-fragmented part that
	 *	will be in every packet... this also means
	 *	that other extension headers (Dest, Auth, etc)
	 *	must be considered in the data to be fragmented
	 */

	unfrag_len = sizeof(struct ipv6hdr) + sizeof(struct frag_hdr);
	last_len = length;

	if (opt) {
		unfrag_len += opt->opt_nflen;
		last_len += opt->opt_flen;
	}

	/*
	 *	Length of fragmented part on every packet but 
	 *	the last must be an:
	 *	"integer multiple of 8 octects".
	 */

	frag_len = (mtu - unfrag_len) & ~0x7;

	/* Unfragmentable part exceeds mtu. */
	if (frag_len <= 0) {
		ipv6_local_error(sk, EMSGSIZE, fl, mtu);
		return -EMSGSIZE;
	}

	nfrags = last_len / frag_len;

	/*
	 *	We must send from end to start because of 
	 *	UDP/ICMP checksums. We do a funny trick:
	 *	fill the last skb first with the fixed
	 *	header (and its data) and then use it
	 *	to create the following segments and send it
	 *	in the end. If the peer is checking the M_flag
	 *	to trigger the reassembly code then this 
	 *	might be a good idea.
	 */

	frag_off = nfrags * frag_len;
	last_len -= frag_off;

	if (last_len == 0) {
		last_len = frag_len;
		frag_off -= frag_len;
		nfrags--;
	}
	data_off = frag_off;

	/* And it is implementation problem: for now we assume, that
	   all the exthdrs will fit to the first fragment.
	 */
	if (opt) {
		if (frag_len < opt->opt_flen) {
			ipv6_local_error(sk, EMSGSIZE, fl, mtu);
			return -EMSGSIZE;
		}
		data_off = frag_off - opt->opt_flen;
	}

	if (flags&MSG_PROBE)
		return 0;

	last_skb = sock_alloc_send_skb(sk, unfrag_len + frag_len +
				       dst->dev->hard_header_len + 15,
				       flags & MSG_DONTWAIT, &err);

	if (last_skb == NULL)
		return err;

	last_skb->dst = dst_clone(dst);

	skb_reserve(last_skb, (dst->dev->hard_header_len + 15) & ~15);

	hdr = ip6_bld_1(sk, last_skb, fl, hlimit, frag_len+unfrag_len);
	prev_hdr = &hdr->nexthdr;

	if (opt && opt->opt_nflen)
		prev_hdr = ipv6_build_nfrag_opts(last_skb, prev_hdr, opt, final_dst, 0);

	prev_hdr = ipv6_build_fraghdr(last_skb, prev_hdr, frag_off);
	fhdr_dist = prev_hdr - last_skb->data;

	err = getfrag(data, &hdr->saddr, last_skb->tail, data_off, last_len);

	if (!err) {
		while (nfrags--) {
			struct sk_buff *skb;
			
			struct frag_hdr *fhdr2;
				
			skb = skb_copy(last_skb, sk->allocation);

			if (skb == NULL) {
				IP6_INC_STATS(Ip6FragFails);
				kfree_skb(last_skb);
				return -ENOMEM;
			}

			frag_off -= frag_len;
			data_off -= frag_len;

			fhdr2 = (struct frag_hdr *) (skb->data + fhdr_dist);

			/* more flag on */
			fhdr2->frag_off = htons(frag_off | 1);

			/* Write fragmentable exthdrs to the first chunk */
			if (nfrags == 0 && opt && opt->opt_flen) {
				ipv6_build_frag_opts(skb, &fhdr2->nexthdr, opt);
				frag_len -= opt->opt_flen;
				data_off = 0;
			}

			err = getfrag(data, &hdr->saddr,skb_put(skb, frag_len),
				      data_off, frag_len);

			if (err) {
				kfree_skb(skb);
				break;
			}

			IP6_INC_STATS(Ip6FragCreates);
			IP6_INC_STATS(Ip6OutRequests);
			err = NF_HOOK(PF_INET6,NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, ip6_maybe_reroute);
			if (err) {
				kfree_skb(last_skb);
				return err;
			}
		}
	}

	if (err) {
		IP6_INC_STATS(Ip6FragFails);
		kfree_skb(last_skb);
		return -EFAULT;
	}

	hdr->payload_len = htons(unfrag_len + last_len - sizeof(struct ipv6hdr));

	/*
	 *	update last_skb to reflect the getfrag we did
	 *	on start.
	 */

	skb_put(last_skb, last_len);

	IP6_INC_STATS(Ip6FragCreates);
	IP6_INC_STATS(Ip6FragOKs);
	IP6_INC_STATS(Ip6OutRequests);
	return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, last_skb, NULL,dst->dev, ip6_maybe_reroute);
}
Пример #11
0
int ip6_route_me_harder(struct sk_buff *skb)
{
	struct net *net = dev_net(skb_dst(skb)->dev);
	const struct ipv6hdr *iph = ipv6_hdr(skb);
	unsigned int hh_len;
	struct dst_entry *dst;
	struct flowi6 fl6 = {
		.flowi6_oif = skb->sk ? skb->sk->sk_bound_dev_if : 0,
		.flowi6_mark = skb->mark,
		.daddr = iph->daddr,
		.saddr = iph->saddr,
	};

	dst = ip6_route_output(net, skb->sk, &fl6);
	if (dst->error) {
		IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
		LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n");
		dst_release(dst);
		return -EINVAL;
	}

	/* Drop old route. */
	skb_dst_drop(skb);

	skb_dst_set(skb, dst);

#ifdef CONFIG_XFRM
	if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
	    xfrm_decode_session(skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) {
		skb_dst_set(skb, NULL);
		dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), skb->sk, 0);
		if (IS_ERR(dst))
			return -1;
		skb_dst_set(skb, dst);
	}
#endif

	/* Change in oif may mean change in hh_len. */
	hh_len = skb_dst(skb)->dev->hard_header_len;
	if (skb_headroom(skb) < hh_len &&
	    pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
			     0, GFP_ATOMIC))
		return -1;

	return 0;
}
EXPORT_SYMBOL(ip6_route_me_harder);

/*
 * Extra routing may needed on local out, as the QUEUE target never
 * returns control to the table.
 */

struct ip6_rt_info {
	struct in6_addr daddr;
	struct in6_addr saddr;
	u_int32_t mark;
};

static void nf_ip6_saveroute(const struct sk_buff *skb,
			     struct nf_queue_entry *entry)
{
	struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);

	if (entry->hook == NF_INET_LOCAL_OUT) {
		const struct ipv6hdr *iph = ipv6_hdr(skb);

		rt_info->daddr = iph->daddr;
		rt_info->saddr = iph->saddr;
		rt_info->mark = skb->mark;
	}
}

static int nf_ip6_reroute(struct sk_buff *skb,
			  const struct nf_queue_entry *entry)
{
	struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);

	if (entry->hook == NF_INET_LOCAL_OUT) {
		const struct ipv6hdr *iph = ipv6_hdr(skb);
		if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
		    !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
		    skb->mark != rt_info->mark)
			return ip6_route_me_harder(skb);
	}
	return 0;
}

static int nf_ip6_route(struct net *net, struct dst_entry **dst,
			struct flowi *fl, bool strict)
{
	static const struct ipv6_pinfo fake_pinfo;
	static const struct inet_sock fake_sk = {
		/* makes ip6_route_output set RT6_LOOKUP_F_IFACE: */
		.sk.sk_bound_dev_if = 1,
		.pinet6 = (struct ipv6_pinfo *) &fake_pinfo,
	};
	const void *sk = strict ? &fake_sk : NULL;
	struct dst_entry *result;
	int err;

	result = ip6_route_output(net, sk, &fl->u.ip6);
	err = result->error;
	if (err)
		dst_release(result);
	else
		*dst = result;
	return err;
}

__sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
			     unsigned int dataoff, u_int8_t protocol)
{
	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
	__sum16 csum = 0;

	switch (skb->ip_summed) {
	case CHECKSUM_COMPLETE:
		if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)
			break;
		if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
				     skb->len - dataoff, protocol,
				     csum_sub(skb->csum,
					      skb_checksum(skb, 0,
							   dataoff, 0)))) {
			skb->ip_summed = CHECKSUM_UNNECESSARY;
			break;
		}
		/* fall through */
	case CHECKSUM_NONE:
		skb->csum = ~csum_unfold(
				csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
					     skb->len - dataoff,
					     protocol,
					     csum_sub(0,
						      skb_checksum(skb, 0,
								   dataoff, 0))));
		csum = __skb_checksum_complete(skb);
	}
	return csum;
}
EXPORT_SYMBOL(nf_ip6_checksum);

static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook,
				       unsigned int dataoff, unsigned int len,
				       u_int8_t protocol)
{
	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
	__wsum hsum;
	__sum16 csum = 0;

	switch (skb->ip_summed) {
	case CHECKSUM_COMPLETE:
		if (len == skb->len - dataoff)
			return nf_ip6_checksum(skb, hook, dataoff, protocol);
		/* fall through */
	case CHECKSUM_NONE:
		hsum = skb_checksum(skb, 0, dataoff, 0);
		skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
							 &ip6h->daddr,
							 skb->len - dataoff,
							 protocol,
							 csum_sub(0, hsum)));
		skb->ip_summed = CHECKSUM_NONE;
		return __skb_checksum_complete_head(skb, dataoff + len);
	}
	return csum;
};

static const struct nf_afinfo nf_ip6_afinfo = {
	.family			= AF_INET6,
	.checksum		= nf_ip6_checksum,
	.checksum_partial	= nf_ip6_checksum_partial,
	.route			= nf_ip6_route,
	.saveroute		= nf_ip6_saveroute,
	.reroute		= nf_ip6_reroute,
	.route_key_size		= sizeof(struct ip6_rt_info),
};

int __init ipv6_netfilter_init(void)
{
	return nf_register_afinfo(&nf_ip6_afinfo);
}

/* This can be called from inet6_init() on errors, so it cannot
 * be marked __exit. -DaveM
 */
void ipv6_netfilter_fini(void)
{
	nf_unregister_afinfo(&nf_ip6_afinfo);
}
Пример #12
0
int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
	     struct ipv6_txoptions *opt, int tclass)
{
	struct net *net = sock_net(sk);
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct in6_addr *first_hop = &fl6->daddr;
	struct dst_entry *dst = skb_dst(skb);
	struct ipv6hdr *hdr;
	u8  proto = fl6->flowi6_proto;
	int seg_len = skb->len;
	int hlimit = -1;
	u32 mtu;

	if (opt) {
		unsigned int head_room;

		/* First: exthdrs may take lots of space (~8K for now)
		   MAX_HEADER is not enough.
		 */
		head_room = opt->opt_nflen + opt->opt_flen;
		seg_len += head_room;
		head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);

		if (skb_headroom(skb) < head_room) {
			struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
			if (!skb2) {
				IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
					      IPSTATS_MIB_OUTDISCARDS);
				kfree_skb(skb);
				return -ENOBUFS;
			}
			consume_skb(skb);
			skb = skb2;
			skb_set_owner_w(skb, sk);
		}
		if (opt->opt_flen)
			ipv6_push_frag_opts(skb, opt, &proto);
		if (opt->opt_nflen)
			ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
	}

	skb_push(skb, sizeof(struct ipv6hdr));
	skb_reset_network_header(skb);
	hdr = ipv6_hdr(skb);

	/*
	 *	Fill in the IPv6 header
	 */
	if (np)
		hlimit = np->hop_limit;
	if (hlimit < 0)
		hlimit = ip6_dst_hoplimit(dst);

	ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel,
						     np->autoflowlabel, fl6));

	hdr->payload_len = htons(seg_len);
	hdr->nexthdr = proto;
	hdr->hop_limit = hlimit;

	hdr->saddr = fl6->saddr;
	hdr->daddr = *first_hop;

	skb->protocol = htons(ETH_P_IPV6);
	skb->priority = sk->sk_priority;
	skb->mark = sk->sk_mark;

	mtu = dst_mtu(dst);
	if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) {
		IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
			      IPSTATS_MIB_OUT, skb->len);
		return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, sk, skb,
			       NULL, dst->dev, dst_output_sk);
	}

	skb->dev = dst->dev;
	ipv6_local_error(sk, EMSGSIZE, fl6, mtu);
	IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS);
	kfree_skb(skb);
	return -EMSGSIZE;
}
static int ip6_dst_lookup_tail(struct sock *sk,
			       struct dst_entry **dst, struct flowi6 *fl6)
{
	struct net *net = sock_net(sk);
#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
	struct neighbour *n;
	struct rt6_info *rt;
#endif
	int err;

	if (*dst == NULL)
		*dst = ip6_route_output(net, sk, fl6);

	if ((err = (*dst)->error))
		goto out_err_release;

	if (ipv6_addr_any(&fl6->saddr)) {
		struct rt6_info *rt = (struct rt6_info *) *dst;
		err = ip6_route_get_saddr(net, rt, &fl6->daddr,
					  sk ? inet6_sk(sk)->srcprefs : 0,
					  &fl6->saddr);
		if (err)
			goto out_err_release;
	}

#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
	/*
	 * Here if the dst entry we've looked up
	 * has a neighbour entry that is in the INCOMPLETE
	 * state and the src address from the flow is
	 * marked as OPTIMISTIC, we release the found
	 * dst entry and replace it instead with the
	 * dst entry of the nexthop router
	 */
	rt = (struct rt6_info *) *dst;
	rcu_read_lock_bh();
	n = __ipv6_neigh_lookup_noref(rt->dst.dev, rt6_nexthop(rt));
	err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0;
	rcu_read_unlock_bh();

	if (err) {
		struct inet6_ifaddr *ifp;
		struct flowi6 fl_gw6;
		int redirect;

		ifp = ipv6_get_ifaddr(net, &fl6->saddr,
				      (*dst)->dev, 1);

		redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
		if (ifp)
			in6_ifa_put(ifp);

		if (redirect) {
			/*
			 * We need to get the dst entry for the
			 * default router instead
			 */
			dst_release(*dst);
			memcpy(&fl_gw6, fl6, sizeof(struct flowi6));
			memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr));
			*dst = ip6_route_output(net, sk, &fl_gw6);
			if ((err = (*dst)->error))
				goto out_err_release;
		}
	}
#endif

	return 0;

out_err_release:
	if (err == -ENETUNREACH)
		IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES);
	dst_release(*dst);
	*dst = NULL;
	return err;
}
static int ip6_finish_output2(struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	struct net_device *dev = dst->dev;
	struct neighbour *neigh;
	struct in6_addr *nexthop;
	int ret;

	skb->protocol = htons(ETH_P_IPV6);
	skb->dev = dev;

	if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
		struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));

		if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(skb->sk) &&
		    ((mroute6_socket(dev_net(dev), skb) &&
		     !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
		     ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
					 &ipv6_hdr(skb)->saddr))) {
			struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);

			/* Do not check for IFF_ALLMULTI; multicast routing
			   is not supported in any case.
			 */
			if (newskb)
				NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING,
					newskb, NULL, newskb->dev,
					dev_loopback_xmit);

			if (ipv6_hdr(skb)->hop_limit == 0) {
				IP6_INC_STATS(dev_net(dev), idev,
					      IPSTATS_MIB_OUTDISCARDS);
				kfree_skb(skb);
				return 0;
			}
		}

		IP6_UPD_PO_STATS(dev_net(dev), idev, IPSTATS_MIB_OUTMCAST,
				skb->len);

		if (IPV6_ADDR_MC_SCOPE(&ipv6_hdr(skb)->daddr) <=
		    IPV6_ADDR_SCOPE_NODELOCAL &&
		    !(dev->flags & IFF_LOOPBACK)) {
			kfree_skb(skb);
			return 0;
		}
	}

	rcu_read_lock_bh();
	nexthop = rt6_nexthop((struct rt6_info *)dst);
	neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
	if (unlikely(!neigh))
		neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
	if (!IS_ERR(neigh)) {
		ret = dst_neigh_output(dst, neigh, skb);
		rcu_read_unlock_bh();
		return ret;
	}
	rcu_read_unlock_bh();

	IP6_INC_STATS(dev_net(dst->dev),
		      ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
	kfree_skb(skb);
	return -EINVAL;
}
Пример #15
0
static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
			   struct frag_hdr *fhdr, int nhoff)
{
	struct sk_buff *prev, *next;
	struct net_device *dev;
	int offset, end;
	struct net *net = dev_net(skb_dst(skb)->dev);

	if (fq->q.last_in & INET_FRAG_COMPLETE)
		goto err;

	offset = ntohs(fhdr->frag_off) & ~0x7;
	end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
			((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));

	if ((unsigned int)end > IPV6_MAXPLEN) {
		IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
				 IPSTATS_MIB_INHDRERRORS);
		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
				  ((u8 *)&fhdr->frag_off -
				   skb_network_header(skb)));
		return -1;
	}

	if (skb->ip_summed == CHECKSUM_COMPLETE) {
		const unsigned char *nh = skb_network_header(skb);
		skb->csum = csum_sub(skb->csum,
				     csum_partial(nh, (u8 *)(fhdr + 1) - nh,
						  0));
	}

	
	if (!(fhdr->frag_off & htons(IP6_MF))) {
		if (end < fq->q.len ||
		    ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len))
			goto err;
		fq->q.last_in |= INET_FRAG_LAST_IN;
		fq->q.len = end;
	} else {
		if (end & 0x7) {
			IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
					 IPSTATS_MIB_INHDRERRORS);
			icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
					  offsetof(struct ipv6hdr, payload_len));
			return -1;
		}
		if (end > fq->q.len) {
			
			if (fq->q.last_in & INET_FRAG_LAST_IN)
				goto err;
			fq->q.len = end;
		}
	}

	if (end == offset)
		goto err;

	
	if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
		goto err;

	if (pskb_trim_rcsum(skb, end - offset))
		goto err;

	prev = fq->q.fragments_tail;
	if (!prev || FRAG6_CB(prev)->offset < offset) {
		next = NULL;
		goto found;
	}
	prev = NULL;
	for(next = fq->q.fragments; next != NULL; next = next->next) {
		if (FRAG6_CB(next)->offset >= offset)
			break;	
		prev = next;
	}

found:

	
	if (prev &&
	    (FRAG6_CB(prev)->offset + prev->len) > offset)
		goto discard_fq;

	
	if (next && FRAG6_CB(next)->offset < end)
		goto discard_fq;

	FRAG6_CB(skb)->offset = offset;

	
	skb->next = next;
	if (!next)
		fq->q.fragments_tail = skb;
	if (prev)
		prev->next = skb;
	else
		fq->q.fragments = skb;

	dev = skb->dev;
	if (dev) {
		fq->iif = dev->ifindex;
		skb->dev = NULL;
	}
	fq->q.stamp = skb->tstamp;
	fq->q.meat += skb->len;
	atomic_add(skb->truesize, &fq->q.net->mem);

	if (offset == 0) {
		fq->nhoffset = nhoff;
		fq->q.last_in |= INET_FRAG_FIRST_IN;
	}

	if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
	    fq->q.meat == fq->q.len)
		return ip6_frag_reasm(fq, prev, dev);

	write_lock(&ip6_frags.lock);
	list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list);
	write_unlock(&ip6_frags.lock);
	return -1;

discard_fq:
	fq_kill(fq);
err:
	IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
		      IPSTATS_MIB_REASMFAILS);
	kfree_skb(skb);
	return -1;
}
Пример #16
0
static void __ndisc_send(struct net_device *dev,
			 struct neighbour *neigh,
			 struct in6_addr *daddr, struct in6_addr *saddr,
			 struct icmp6hdr *icmp6h, struct in6_addr *target,
			 int llinfo, int icmp6_mib_outnd)
{
	struct flowi fl;
	struct dst_entry *dst;
	struct sock *sk = ndisc_socket->sk;
	struct sk_buff *skb;
	struct icmp6hdr *hdr;
	struct inet6_dev *idev;
	int len;
	int err;
	u8 *opt;

	ndisc_flow_init(&fl, icmp6h->icmp6_type, saddr, daddr,
			dev->ifindex);

	dst = ndisc_dst_alloc(dev, neigh, daddr, ip6_output);
	if (!dst)
		return;

	err = xfrm_lookup(&dst, &fl, NULL, 0);
	if (err < 0)
		return;

	if (!dev->addr_len)
		llinfo = 0;

	len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0);
	if (llinfo)
		len += ndisc_opt_addr_space(dev);

	skb = sock_alloc_send_skb(sk,
				  (MAX_HEADER + sizeof(struct ipv6hdr) +
				   len + LL_RESERVED_SPACE(dev)),
				  1, &err);
	if (!skb) {
		ND_PRINTK0(KERN_ERR
			   "ICMPv6 ND: %s() failed to allocate an skb.\n",
			   __FUNCTION__);
		dst_release(dst);
		return;
	}

	skb_reserve(skb, LL_RESERVED_SPACE(dev));
	ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);

	skb->transport_header = skb->tail;
	skb_put(skb, len);

	hdr = (struct icmp6hdr *)skb_transport_header(skb);
	memcpy(hdr, icmp6h, sizeof(*hdr));

	opt = skb_transport_header(skb) + sizeof(struct icmp6hdr);
	if (target) {
		ipv6_addr_copy((struct in6_addr *)opt, target);
		opt += sizeof(*target);
	}

	if (llinfo)
		ndisc_fill_addr_option(opt, llinfo, dev->dev_addr,
				       dev->addr_len, dev->type);

	hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len,
					   IPPROTO_ICMPV6,
					   csum_partial((__u8 *) hdr,
							len, 0));

	skb->dst = dst;

	idev = in6_dev_get(dst->dev);
	IP6_INC_STATS(idev, IPSTATS_MIB_OUTREQUESTS);

	err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, dst_output);
	if (!err) {
		ICMP6_INC_STATS(idev, icmp6_mib_outnd);
		ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
	}

	if (likely(idev != NULL))
		in6_dev_put(idev);
}
Пример #17
0
static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk,
			       struct dst_entry **dst, struct flowi6 *fl6)
{
#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
	struct neighbour *n;
	struct rt6_info *rt;
#endif
	int err;
	int flags = 0;

	/* The correct way to handle this would be to do
	 * ip6_route_get_saddr, and then ip6_route_output; however,
	 * the route-specific preferred source forces the
	 * ip6_route_output call _before_ ip6_route_get_saddr.
	 *
	 * In source specific routing (no src=any default route),
	 * ip6_route_output will fail given src=any saddr, though, so
	 * that's why we try it again later.
	 */
	if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) {
		struct rt6_info *rt;
		bool had_dst = *dst != NULL;

		if (!had_dst)
			*dst = ip6_route_output(net, sk, fl6);
		rt = (*dst)->error ? NULL : (struct rt6_info *)*dst;
		err = ip6_route_get_saddr(net, rt, &fl6->daddr,
					  sk ? inet6_sk(sk)->srcprefs : 0,
					  &fl6->saddr);
		if (err)
			goto out_err_release;

		/* If we had an erroneous initial result, pretend it
		 * never existed and let the SA-enabled version take
		 * over.
		 */
		if (!had_dst && (*dst)->error) {
			dst_release(*dst);
			*dst = NULL;
		}

		if (fl6->flowi6_oif)
			flags |= RT6_LOOKUP_F_IFACE;
	}

	if (!*dst)
		*dst = ip6_route_output_flags(net, sk, fl6, flags);

	err = (*dst)->error;
	if (err)
		goto out_err_release;

#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
	/*
	 * Here if the dst entry we've looked up
	 * has a neighbour entry that is in the INCOMPLETE
	 * state and the src address from the flow is
	 * marked as OPTIMISTIC, we release the found
	 * dst entry and replace it instead with the
	 * dst entry of the nexthop router
	 */
	rt = (struct rt6_info *) *dst;
	rcu_read_lock_bh();
	n = __ipv6_neigh_lookup_noref(rt->dst.dev,
				      rt6_nexthop(rt, &fl6->daddr));
	err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0;
	rcu_read_unlock_bh();

	if (err) {
		struct inet6_ifaddr *ifp;
		struct flowi6 fl_gw6;
		int redirect;

		ifp = ipv6_get_ifaddr(net, &fl6->saddr,
				      (*dst)->dev, 1);

		redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
		if (ifp)
			in6_ifa_put(ifp);

		if (redirect) {
			/*
			 * We need to get the dst entry for the
			 * default router instead
			 */
			dst_release(*dst);
			memcpy(&fl_gw6, fl6, sizeof(struct flowi6));
			memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr));
			*dst = ip6_route_output(net, sk, &fl_gw6);
			err = (*dst)->error;
			if (err)
				goto out_err_release;
		}
	}
#endif

	return 0;

out_err_release:
	if (err == -ENETUNREACH)
		IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES);
	dst_release(*dst);
	*dst = NULL;
	return err;
}
Пример #18
0
static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
			   struct frag_hdr *fhdr, int nhoff)
{
	struct sk_buff *prev, *next;
	struct net_device *dev;
	int offset, end;
	struct net *net = dev_net(skb_dst(skb)->dev);

	if (fq->q.last_in & INET_FRAG_COMPLETE)
		goto err;

	offset = ntohs(fhdr->frag_off) & ~0x7;
	end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
			((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));

	if ((unsigned int)end > IPV6_MAXPLEN) {
		IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
				 IPSTATS_MIB_INHDRERRORS);
		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
				  ((u8 *)&fhdr->frag_off -
				   skb_network_header(skb)));
		return -1;
	}

	if (skb->ip_summed == CHECKSUM_COMPLETE) {
		const unsigned char *nh = skb_network_header(skb);
		skb->csum = csum_sub(skb->csum,
				     csum_partial(nh, (u8 *)(fhdr + 1) - nh,
						  0));
	}

	/* Is this the final fragment? */
	if (!(fhdr->frag_off & htons(IP6_MF))) {
		/* If we already have some bits beyond end
		 * or have different end, the segment is corrupted.
		 */
		if (end < fq->q.len ||
		    ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len))
			goto err;
		fq->q.last_in |= INET_FRAG_LAST_IN;
		fq->q.len = end;
	} else {
		/* Check if the fragment is rounded to 8 bytes.
		 * Required by the RFC.
		 */
		if (end & 0x7) {
			/* RFC2460 says always send parameter problem in
			 * this case. -DaveM
			 */
			IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
					 IPSTATS_MIB_INHDRERRORS);
			icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
					  offsetof(struct ipv6hdr, payload_len));
			return -1;
		}
		if (end > fq->q.len) {
			/* Some bits beyond end -> corruption. */
			if (fq->q.last_in & INET_FRAG_LAST_IN)
				goto err;
			fq->q.len = end;
		}
	}

	if (end == offset)
		goto err;

	/* Point into the IP datagram 'data' part. */
	if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
		goto err;

	if (pskb_trim_rcsum(skb, end - offset))
		goto err;

	/* Find out which fragments are in front and at the back of us
	 * in the chain of fragments so far.  We must know where to put
	 * this fragment, right?
	 */
	prev = fq->q.fragments_tail;
	if (!prev || FRAG6_CB(prev)->offset < offset) {
		next = NULL;
		goto found;
	}
	prev = NULL;
	for(next = fq->q.fragments; next != NULL; next = next->next) {
		if (FRAG6_CB(next)->offset >= offset)
			break;	/* bingo! */
		prev = next;
	}

found:
	/* RFC5722, Section 4, amended by Errata ID : 3089
	 *                          When reassembling an IPv6 datagram, if
	 *   one or more its constituent fragments is determined to be an
	 *   overlapping fragment, the entire datagram (and any constituent
	 *   fragments) MUST be silently discarded.
	 */

	/* Check for overlap with preceding fragment. */
	if (prev &&
	    (FRAG6_CB(prev)->offset + prev->len) > offset)
		goto discard_fq;

	/* Look for overlap with succeeding segment. */
	if (next && FRAG6_CB(next)->offset < end)
		goto discard_fq;

	FRAG6_CB(skb)->offset = offset;

	/* Insert this fragment in the chain of fragments. */
	skb->next = next;
	if (!next)
		fq->q.fragments_tail = skb;
	if (prev)
		prev->next = skb;
	else
		fq->q.fragments = skb;

	dev = skb->dev;
	if (dev) {
		fq->iif = dev->ifindex;
		skb->dev = NULL;
	}
	fq->q.stamp = skb->tstamp;
	fq->q.meat += skb->len;
	atomic_add(skb->truesize, &fq->q.net->mem);

	/* The first fragment.
	 * nhoffset is obtained from the first fragment, of course.
	 */
	if (offset == 0) {
		fq->nhoffset = nhoff;
		fq->q.last_in |= INET_FRAG_FIRST_IN;
	}

	if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
	    fq->q.meat == fq->q.len)
		return ip6_frag_reasm(fq, prev, dev);

	write_lock(&ip6_frags.lock);
	list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list);
	write_unlock(&ip6_frags.lock);
	return -1;

discard_fq:
	fq_kill(fq);
err:
	IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
		      IPSTATS_MIB_REASMFAILS);
	kfree_skb(skb);
	return -1;
}
Пример #19
0
int ip6_push_pending_frames(struct sock *sk)
{
	struct sk_buff *skb, *tmp_skb;
	struct sk_buff **tail_skb;
	struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
	struct inet_sock *inet = inet_sk(sk);
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct ipv6hdr *hdr;
	struct ipv6_txoptions *opt = np->cork.opt;
	struct rt6_info *rt = np->cork.rt;
	struct flowi *fl = &inet->cork.fl;
	unsigned char proto = fl->proto;
	int err = 0;

	if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
		goto out;
	tail_skb = &(skb_shinfo(skb)->frag_list);

	/* move skb->data to ip header from ext header */
	if (skb->data < skb->nh.raw)
		__skb_pull(skb, skb->nh.raw - skb->data);
	while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
		__skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
		*tail_skb = tmp_skb;
		tail_skb = &(tmp_skb->next);
		skb->len += tmp_skb->len;
		skb->data_len += tmp_skb->len;
		skb->truesize += tmp_skb->truesize;
		__sock_put(tmp_skb->sk);
		tmp_skb->destructor = NULL;
		tmp_skb->sk = NULL;
	}

	ipv6_addr_copy(final_dst, &fl->fl6_dst);
	__skb_pull(skb, skb->h.raw - skb->nh.raw);
	if (opt && opt->opt_flen)
		ipv6_push_frag_opts(skb, opt, &proto);
	if (opt && opt->opt_nflen)
		ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);

	skb->nh.ipv6h = hdr = (struct ipv6hdr*) skb_push(skb, sizeof(struct ipv6hdr));
	
	*(u32*)hdr = fl->fl6_flowlabel | htonl(0x60000000);

	if (skb->len <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN)
		hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
	else
		hdr->payload_len = 0;
	hdr->hop_limit = np->cork.hop_limit;
	hdr->nexthdr = proto;
	ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
	ipv6_addr_copy(&hdr->daddr, final_dst);

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

out:
	inet->cork.flags &= ~IPCORK_OPT;
	if (np->cork.opt) {
		kfree(np->cork.opt);
		np->cork.opt = NULL;
	}
	if (np->cork.rt) {
		dst_release(&np->cork.rt->u.dst);
		np->cork.rt = NULL;
		inet->cork.flags &= ~IPCORK_ALLFRAG;
	}
	memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
	return err;
error:
	goto out;
}
Пример #20
0
int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
	int offset, int len, int odd, struct sk_buff *skb),
	void *from, int length, int transhdrlen,
	int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
	struct rt6_info *rt, unsigned int flags, int dontfrag)
{
	struct inet_sock *inet = inet_sk(sk);
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct inet_cork *cork;
	struct sk_buff *skb, *skb_prev = NULL;
	unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu;
	int exthdrlen;
	int dst_exthdrlen;
	int hh_len;
	int copy;
	int err;
	int offset = 0;
	int csummode = CHECKSUM_NONE;
	__u8 tx_flags = 0;

	if (flags&MSG_PROBE)
		return 0;
	cork = &inet->cork.base;
	if (skb_queue_empty(&sk->sk_write_queue)) {
		/*
		 * setup for corking
		 */
		if (opt) {
			if (WARN_ON(np->cork.opt))
				return -EINVAL;

			np->cork.opt = kzalloc(opt->tot_len, sk->sk_allocation);
			if (unlikely(np->cork.opt == NULL))
				return -ENOBUFS;

			np->cork.opt->tot_len = opt->tot_len;
			np->cork.opt->opt_flen = opt->opt_flen;
			np->cork.opt->opt_nflen = opt->opt_nflen;

			np->cork.opt->dst0opt = ip6_opt_dup(opt->dst0opt,
							    sk->sk_allocation);
			if (opt->dst0opt && !np->cork.opt->dst0opt)
				return -ENOBUFS;

			np->cork.opt->dst1opt = ip6_opt_dup(opt->dst1opt,
							    sk->sk_allocation);
			if (opt->dst1opt && !np->cork.opt->dst1opt)
				return -ENOBUFS;

			np->cork.opt->hopopt = ip6_opt_dup(opt->hopopt,
							   sk->sk_allocation);
			if (opt->hopopt && !np->cork.opt->hopopt)
				return -ENOBUFS;

			np->cork.opt->srcrt = ip6_rthdr_dup(opt->srcrt,
							    sk->sk_allocation);
			if (opt->srcrt && !np->cork.opt->srcrt)
				return -ENOBUFS;

			/* need source address above miyazawa*/
		}
		dst_hold(&rt->dst);
		cork->dst = &rt->dst;
		inet->cork.fl.u.ip6 = *fl6;
		np->cork.hop_limit = hlimit;
		np->cork.tclass = tclass;
		if (rt->dst.flags & DST_XFRM_TUNNEL)
			mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
			      rt->dst.dev->mtu : dst_mtu(&rt->dst);
		else
			mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
			      rt->dst.dev->mtu : dst_mtu(rt->dst.path);
		if (np->frag_size < mtu) {
			if (np->frag_size)
				mtu = np->frag_size;
		}
		cork->fragsize = mtu;
		if (dst_allfrag(rt->dst.path))
			cork->flags |= IPCORK_ALLFRAG;
		cork->length = 0;
		sk->sk_sndmsg_page = NULL;
		sk->sk_sndmsg_off = 0;
		exthdrlen = (opt ? opt->opt_flen : 0);
		length += exthdrlen;
		transhdrlen += exthdrlen;
		dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len;
	} else {
		rt = (struct rt6_info *)cork->dst;
		fl6 = &inet->cork.fl.u.ip6;
		opt = np->cork.opt;
		transhdrlen = 0;
		exthdrlen = 0;
		dst_exthdrlen = 0;
		mtu = cork->fragsize;
	}
	orig_mtu = mtu;

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

	fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
			(opt ? opt->opt_nflen : 0);
	maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);

	if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
		if (cork->length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
			ipv6_local_error(sk, EMSGSIZE, fl6, mtu-exthdrlen);
			return -EMSGSIZE;
		}
	}

	/* For UDP, check if TX timestamp is enabled */
	if (sk->sk_type == SOCK_DGRAM) {
		err = sock_tx_timestamp(sk, &tx_flags);
		if (err)
			goto error;
	}

	/*
	 * Let's try using as much space as possible.
	 * Use MTU if total length of the message fits into the MTU.
	 * Otherwise, we need to reserve fragment header and
	 * fragment alignment (= 8-15 octects, in total).
	 *
	 * Note that we may need to "move" the data from the tail of
	 * of the buffer to the new fragment when we split
	 * the message.
	 *
	 * FIXME: It may be fragmented into multiple chunks
	 *        at once if non-fragmentable extension headers
	 *        are too large.
	 * --yoshfuji
	 */

	if ((length > mtu) && dontfrag && (sk->sk_protocol == IPPROTO_UDP ||
					   sk->sk_protocol == IPPROTO_RAW)) {
		ipv6_local_rxpmtu(sk, fl6, mtu-exthdrlen);
		return -EMSGSIZE;
	}

	skb = skb_peek_tail(&sk->sk_write_queue);
	cork->length += length;
	if (((length > mtu) ||
	     (skb && skb_has_frags(skb))) &&
	    (sk->sk_protocol == IPPROTO_UDP) &&
	    (rt->dst.dev->features & NETIF_F_UFO)) {
		err = ip6_ufo_append_data(sk, getfrag, from, length,
					  hh_len, fragheaderlen,
					  transhdrlen, mtu, flags, rt);
		if (err)
			goto error;
		return 0;
	}

	if (!skb)
		goto alloc_new_skb;

	while (length > 0) {
		/* Check if the remaining data fits into current packet. */
		copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
		if (copy < length)
			copy = maxfraglen - skb->len;

		if (copy <= 0) {
			char *data;
			unsigned int datalen;
			unsigned int fraglen;
			unsigned int fraggap;
			unsigned int alloclen;
alloc_new_skb:
			/* There's no room in the current skb */
			if (skb)
				fraggap = skb->len - maxfraglen;
			else
				fraggap = 0;
			/* update mtu and maxfraglen if necessary */
			if (skb == NULL || skb_prev == NULL)
				ip6_append_data_mtu(&mtu, &maxfraglen,
						    fragheaderlen, skb, rt,
						    orig_mtu);

			skb_prev = skb;

			/*
			 * If remaining data exceeds the mtu,
			 * we know we need more fragment(s).
			 */
			datalen = length + fraggap;

			if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
				datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
			if ((flags & MSG_MORE) &&
			    !(rt->dst.dev->features&NETIF_F_SG))
				alloclen = mtu;
			else
				alloclen = datalen + fragheaderlen;

			alloclen += dst_exthdrlen;

			if (datalen != length + fraggap) {
				/*
				 * this is not the last fragment, the trailer
				 * space is regarded as data space.
				 */
				datalen += rt->dst.trailer_len;
			}

			alloclen += rt->dst.trailer_len;
			fraglen = datalen + fragheaderlen;

			/*
			 * We just reserve space for fragment header.
			 * Note: this may be overallocation if the message
			 * (without MSG_MORE) fits into the MTU.
			 */
			alloclen += sizeof(struct frag_hdr);

			if (transhdrlen) {
				skb = sock_alloc_send_skb(sk,
						alloclen + hh_len,
						(flags & MSG_DONTWAIT), &err);
			} else {
				skb = NULL;
				if (atomic_read(&sk->sk_wmem_alloc) <=
				    2 * sk->sk_sndbuf)
					skb = sock_wmalloc(sk,
							   alloclen + hh_len, 1,
							   sk->sk_allocation);
				if (unlikely(skb == NULL))
					err = -ENOBUFS;
				else {
					/* Only the initial fragment
					 * is time stamped.
					 */
					tx_flags = 0;
				}
			}
			if (skb == NULL)
				goto error;
			/*
			 *	Fill in the control structures
			 */
			skb->ip_summed = csummode;
			skb->csum = 0;
			/* reserve for fragmentation and ipsec header */
			skb_reserve(skb, hh_len + sizeof(struct frag_hdr) +
				    dst_exthdrlen);

			if (sk->sk_type == SOCK_DGRAM)
				skb_shinfo(skb)->tx_flags = tx_flags;

			/*
			 *	Find where to start putting bytes
			 */
			data = skb_put(skb, fraglen);
			skb_set_network_header(skb, exthdrlen);
			data += fragheaderlen;
			skb->transport_header = (skb->network_header +
						 fragheaderlen);
			if (fraggap) {
				skb->csum = skb_copy_and_csum_bits(
					skb_prev, maxfraglen,
					data + transhdrlen, fraggap, 0);
				skb_prev->csum = csum_sub(skb_prev->csum,
							  skb->csum);
				data += fraggap;
				pskb_trim_unique(skb_prev, maxfraglen);
			}
			copy = datalen - transhdrlen - fraggap;

			if (copy < 0) {
				err = -EINVAL;
				kfree_skb(skb);
				goto error;
			} else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
				err = -EFAULT;
				kfree_skb(skb);
				goto error;
			}

			offset += copy;
			length -= datalen - fraggap;
			transhdrlen = 0;
			exthdrlen = 0;
			dst_exthdrlen = 0;
			csummode = CHECKSUM_NONE;

			/*
			 * Put the packet on the pending queue
			 */
			__skb_queue_tail(&sk->sk_write_queue, skb);
			continue;
		}

		if (copy > length)
			copy = length;

		if (!(rt->dst.dev->features&NETIF_F_SG)) {
			unsigned int off;

			off = skb->len;
			if (getfrag(from, skb_put(skb, copy),
						offset, copy, off, skb) < 0) {
				__skb_trim(skb, off);
				err = -EFAULT;
				goto error;
			}
		} else {
			int i = skb_shinfo(skb)->nr_frags;
			skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
			struct page *page = sk->sk_sndmsg_page;
			int off = sk->sk_sndmsg_off;
			unsigned int left;

			if (page && (left = PAGE_SIZE - off) > 0) {
				if (copy >= left)
					copy = left;
				if (page != skb_frag_page(frag)) {
					if (i == MAX_SKB_FRAGS) {
						err = -EMSGSIZE;
						goto error;
					}
					skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
					skb_frag_ref(skb, i);
					frag = &skb_shinfo(skb)->frags[i];
				}
			} else if(i < MAX_SKB_FRAGS) {
				if (copy > PAGE_SIZE)
					copy = PAGE_SIZE;
				page = alloc_pages(sk->sk_allocation, 0);
				if (page == NULL) {
					err = -ENOMEM;
					goto error;
				}
				sk->sk_sndmsg_page = page;
				sk->sk_sndmsg_off = 0;

				skb_fill_page_desc(skb, i, page, 0, 0);
				frag = &skb_shinfo(skb)->frags[i];
			} else {
				err = -EMSGSIZE;
				goto error;
			}
			if (getfrag(from,
				    skb_frag_address(frag) + skb_frag_size(frag),
				    offset, copy, skb->len, skb) < 0) {
				err = -EFAULT;
				goto error;
			}
			sk->sk_sndmsg_off += copy;
			skb_frag_size_add(frag, copy);
			skb->len += copy;
			skb->data_len += copy;
			skb->truesize += copy;
			atomic_add(copy, &sk->sk_wmem_alloc);
		}
		offset += copy;
		length -= copy;
	}
	return 0;
error:
	cork->length -= length;
	IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
	return err;
}
Пример #21
0
int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
	     struct ipv6_txoptions *opt, int ipfragok)
{
	struct ipv6_pinfo *np = sk ? inet6_sk(sk) : NULL;
	struct in6_addr *first_hop = &fl->fl6_dst;
	struct dst_entry *dst = skb->dst;
	struct ipv6hdr *hdr;
	u8  proto = fl->proto;
	int seg_len = skb->len;
	int hlimit;
	u32 mtu;

	if (opt) {
		int head_room;

		/* First: exthdrs may take lots of space (~8K for now)
		   MAX_HEADER is not enough.
		 */
		head_room = opt->opt_nflen + opt->opt_flen;
		seg_len += head_room;
		head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);

		if (skb_headroom(skb) < head_room) {
			struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
			kfree_skb(skb);
			skb = skb2;
			if (skb == NULL) {	
				IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
				return -ENOBUFS;
			}
			if (sk)
				skb_set_owner_w(skb, sk);
		}
		if (opt->opt_flen)
			ipv6_push_frag_opts(skb, opt, &proto);
		if (opt->opt_nflen)
			ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
	}

	hdr = skb->nh.ipv6h = (struct ipv6hdr*)skb_push(skb, sizeof(struct ipv6hdr));

	/*
	 *	Fill in the IPv6 header
	 */

	*(u32*)hdr = htonl(0x60000000) | fl->fl6_flowlabel;
	hlimit = -1;
	if (np)
		hlimit = np->hop_limit;
	if (hlimit < 0)
		hlimit = dst_metric(dst, RTAX_HOPLIMIT);
	if (hlimit < 0)
		hlimit = ipv6_get_hoplimit(dst->dev);

	hdr->payload_len = htons(seg_len);
	hdr->nexthdr = proto;
	hdr->hop_limit = hlimit;

	ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
	ipv6_addr_copy(&hdr->daddr, first_hop);

	mtu = dst_mtu(dst);
	if ((skb->len <= mtu) || ipfragok) {
		IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
		return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, ip6_maybe_reroute);
	}

	if (net_ratelimit())
		printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n");
	skb->dev = dst->dev;
	icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
	IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
	kfree_skb(skb);
	return -EMSGSIZE;
}
Пример #22
0
int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
	     struct ipv6_txoptions *opt, int tclass)
{
	struct net *net = sock_net(sk);
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct in6_addr *first_hop = &fl6->daddr;
	struct dst_entry *dst = skb_dst(skb);
	struct ipv6hdr *hdr;
	u8  proto = fl6->flowi6_proto;
	int seg_len = skb->len;
	int hlimit = -1;
	u32 mtu;

	if (opt) {
		unsigned int head_room;

		/* First: exthdrs may take lots of space (~8K for now)
		   MAX_HEADER is not enough.
		 */
		head_room = opt->opt_nflen + opt->opt_flen;
		seg_len += head_room;
		head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);

		if (skb_headroom(skb) < head_room) {
			struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
			if (skb2 == NULL) {
				IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
					      IPSTATS_MIB_OUTDISCARDS);
				kfree_skb(skb);
				return -ENOBUFS;
			}
			kfree_skb(skb);
			skb = skb2;
			skb_set_owner_w(skb, sk);
		}
		if (opt->opt_flen)
			ipv6_push_frag_opts(skb, opt, &proto);
		if (opt->opt_nflen)
			ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
	}

	skb_push(skb, sizeof(struct ipv6hdr));
	skb_reset_network_header(skb);
	hdr = ipv6_hdr(skb);

	/*
	 *	Fill in the IPv6 header
	 */
	if (np)
		hlimit = np->hop_limit;
	if (hlimit < 0)
		hlimit = ip6_dst_hoplimit(dst);

	*(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl6->flowlabel;

	hdr->payload_len = htons(seg_len);
	hdr->nexthdr = proto;
	hdr->hop_limit = hlimit;

	hdr->saddr = fl6->saddr;
	hdr->daddr = *first_hop;

	skb->priority = sk->sk_priority;
	skb->mark = sk->sk_mark;

	mtu = dst_mtu(dst);
	if ((skb->len <= mtu) || skb->local_df || skb_is_gso(skb)) {
		IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
			      IPSTATS_MIB_OUT, skb->len);
		return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL,
			       dst->dev, dst_output);
	}

	net_dbg_ratelimited("IPv6: sending pkt_too_big to self\n");
	skb->dev = dst->dev;
	icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
	IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS);
	kfree_skb(skb);
	return -EMSGSIZE;
}
Пример #23
0
int ip6_forward(struct sk_buff *skb)
{
	struct dst_entry *dst = skb->dst;
	struct ipv6hdr *hdr = skb->nh.ipv6h;
	struct inet6_skb_parm *opt = IP6CB(skb);
	
	if (ipv6_devconf.forwarding == 0)
		goto error;

	if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
		IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
		goto drop;
	}

	skb->ip_summed = CHECKSUM_NONE;

	/*
	 *	We DO NOT make any processing on
	 *	RA packets, pushing them to user level AS IS
	 *	without ane WARRANTY that application will be able
	 *	to interpret them. The reason is that we
	 *	cannot make anything clever here.
	 *
	 *	We are not end-node, so that if packet contains
	 *	AH/ESP, we cannot make anything.
	 *	Defragmentation also would be mistake, RA packets
	 *	cannot be fragmented, because there is no warranty
	 *	that different fragments will go along one path. --ANK
	 */
	if (opt->ra) {
		u8 *ptr = skb->nh.raw + opt->ra;
		if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
			return 0;
	}

	/*
	 *	check and decrement ttl
	 */
	if (hdr->hop_limit <= 1) {
		/* Force OUTPUT device used as source address */
		skb->dev = dst->dev;
		icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
			    0, skb->dev);

		kfree_skb(skb);
		return -ETIMEDOUT;
	}

	if (!xfrm6_route_forward(skb)) {
		IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
		goto drop;
	}
	dst = skb->dst;

	/* IPv6 specs say nothing about it, but it is clear that we cannot
	   send redirects to source routed frames.
	 */
	if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0) {
		struct in6_addr *target = NULL;
		struct rt6_info *rt;
		struct neighbour *n = dst->neighbour;

		/*
		 *	incoming and outgoing devices are the same
		 *	send a redirect.
		 */

		rt = (struct rt6_info *) dst;
		if ((rt->rt6i_flags & RTF_GATEWAY))
			target = (struct in6_addr*)&n->primary_key;
		else
			target = &hdr->daddr;

		/* Limit redirects both by destination (here)
		   and by source (inside ndisc_send_redirect)
		 */
		if (xrlim_allow(dst, 1*HZ))
			ndisc_send_redirect(skb, n, target);
	} else if (ipv6_addr_type(&hdr->saddr)&(IPV6_ADDR_MULTICAST|IPV6_ADDR_LOOPBACK
						|IPV6_ADDR_LINKLOCAL)) {
		/* This check is security critical. */
		goto error;
	}

	if (skb->len > dst_mtu(dst)) {
		/* Again, force OUTPUT device used as source address */
		skb->dev = dst->dev;
		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, dst_mtu(dst), skb->dev);
		IP6_INC_STATS_BH(IPSTATS_MIB_INTOOBIGERRORS);
		IP6_INC_STATS_BH(IPSTATS_MIB_FRAGFAILS);
		kfree_skb(skb);
		return -EMSGSIZE;
	}

	if (skb_cow(skb, dst->dev->hard_header_len)) {
		IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
		goto drop;
	}

	hdr = skb->nh.ipv6h;

	/* Mangling hops number delayed to point after skb COW */
 
	hdr->hop_limit--;

	IP6_INC_STATS_BH(IPSTATS_MIB_OUTFORWDATAGRAMS);
	return NF_HOOK(PF_INET6,NF_IP6_FORWARD, skb, skb->dev, dst->dev, ip6_forward_finish);

error:
	IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
drop:
	kfree_skb(skb);
	return -EINVAL;
}
Пример #24
0
int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
{
	struct sk_buff *frag;
	struct rt6_info *rt = (struct rt6_info*)skb_dst(skb);
	struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
	struct ipv6hdr *tmp_hdr;
	struct frag_hdr *fh;
	unsigned int mtu, hlen, left, len;
	int hroom, troom;
	__be32 frag_id = 0;
	int ptr, offset = 0, err=0;
	u8 *prevhdr, nexthdr = 0;
	struct net *net = dev_net(skb_dst(skb)->dev);

	hlen = ip6_find_1stfragopt(skb, &prevhdr);
	nexthdr = *prevhdr;

	mtu = ip6_skb_dst_mtu(skb);

	/* We must not fragment if the socket is set to force MTU discovery
	 * or if the skb it not generated by a local socket.
	 */
	if (!skb->local_df && skb->len > mtu) {
		skb->dev = skb_dst(skb)->dev;
		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
		IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
			      IPSTATS_MIB_FRAGFAILS);
		kfree_skb(skb);
		return -EMSGSIZE;
	}

	if (np && np->frag_size < mtu) {
		if (np->frag_size)
			mtu = np->frag_size;
	}
	mtu -= hlen + sizeof(struct frag_hdr);

	if (skb_has_frag_list(skb)) {
		int first_len = skb_pagelen(skb);
		struct sk_buff *frag2;

		if (first_len - hlen > mtu ||
		    ((first_len - hlen) & 7) ||
		    skb_cloned(skb))
			goto slow_path;

		skb_walk_frags(skb, frag) {
			/* Correct geometry. */
			if (frag->len > mtu ||
			    ((frag->len & 7) && frag->next) ||
			    skb_headroom(frag) < hlen)
				goto slow_path_clean;

			/* Partially cloned skb? */
			if (skb_shared(frag))
				goto slow_path_clean;

			BUG_ON(frag->sk);
			if (skb->sk) {
				frag->sk = skb->sk;
				frag->destructor = sock_wfree;
			}
			skb->truesize -= frag->truesize;
		}

		err = 0;
		offset = 0;
		frag = skb_shinfo(skb)->frag_list;
		skb_frag_list_init(skb);
		/* BUILD HEADER */

		*prevhdr = NEXTHDR_FRAGMENT;
		tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
		if (!tmp_hdr) {
			IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
				      IPSTATS_MIB_FRAGFAILS);
			return -ENOMEM;
		}

		__skb_pull(skb, hlen);
		fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
		__skb_push(skb, hlen);
		skb_reset_network_header(skb);
		memcpy(skb_network_header(skb), tmp_hdr, hlen);

		ipv6_select_ident(fh, rt);
		fh->nexthdr = nexthdr;
		fh->reserved = 0;
		fh->frag_off = htons(IP6_MF);
		frag_id = fh->identification;

		first_len = skb_pagelen(skb);
		skb->data_len = first_len - skb_headlen(skb);
		skb->len = first_len;
		ipv6_hdr(skb)->payload_len = htons(first_len -
						   sizeof(struct ipv6hdr));

		dst_hold(&rt->dst);

		for (;;) {
			/* Prepare header of the next frame,
			 * before previous one went down. */
			if (frag) {
				frag->ip_summed = CHECKSUM_NONE;
				skb_reset_transport_header(frag);
				fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
				__skb_push(frag, hlen);
				skb_reset_network_header(frag);
				memcpy(skb_network_header(frag), tmp_hdr,
				       hlen);
				offset += skb->len - hlen - sizeof(struct frag_hdr);
				fh->nexthdr = nexthdr;
				fh->reserved = 0;
				fh->frag_off = htons(offset);
				if (frag->next != NULL)
					fh->frag_off |= htons(IP6_MF);
				fh->identification = frag_id;
				ipv6_hdr(frag)->payload_len =
						htons(frag->len -
						      sizeof(struct ipv6hdr));
				ip6_copy_metadata(frag, skb);
			}

			err = output(skb);
			if(!err)
				IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
					      IPSTATS_MIB_FRAGCREATES);

			if (err || !frag)
				break;

			skb = frag;
			frag = skb->next;
			skb->next = NULL;
		}

		kfree(tmp_hdr);

		if (err == 0) {
			IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
				      IPSTATS_MIB_FRAGOKS);
			dst_release(&rt->dst);
			return 0;
		}

		while (frag) {
			skb = frag->next;
			kfree_skb(frag);
			frag = skb;
		}

		IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
			      IPSTATS_MIB_FRAGFAILS);
		dst_release(&rt->dst);
		return err;

slow_path_clean:
		skb_walk_frags(skb, frag2) {
			if (frag2 == frag)
				break;
			frag2->sk = NULL;
			frag2->destructor = NULL;
			skb->truesize += frag2->truesize;
		}
	}

slow_path:
	left = skb->len - hlen;		/* Space per frame */
	ptr = hlen;			/* Where to start from */

	/*
	 *	Fragment the datagram.
	 */

	*prevhdr = NEXTHDR_FRAGMENT;
	hroom = LL_RESERVED_SPACE(rt->dst.dev);
	troom = rt->dst.dev->needed_tailroom;

	/*
	 *	Keep copying data until we run out.
	 */
	while(left > 0)	{
		len = left;
		/* IF: it doesn't fit, use 'mtu' - the data space left */
		if (len > mtu)
			len = mtu;
		/* IF: we are not sending up to and including the packet end
		   then align the next start on an eight byte boundary */
		if (len < left)	{
			len &= ~7;
		}
		/*
		 *	Allocate buffer.
		 */

		if ((frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) +
				      hroom + troom, GFP_ATOMIC)) == NULL) {
			NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
			IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
				      IPSTATS_MIB_FRAGFAILS);
			err = -ENOMEM;
			goto fail;
		}

		/*
		 *	Set up data on packet
		 */

		ip6_copy_metadata(frag, skb);
		skb_reserve(frag, hroom);
		skb_put(frag, len + hlen + sizeof(struct frag_hdr));
		skb_reset_network_header(frag);
		fh = (struct frag_hdr *)(skb_network_header(frag) + hlen);
		frag->transport_header = (frag->network_header + hlen +
					  sizeof(struct frag_hdr));

		/*
		 *	Charge the memory for the fragment to any owner
		 *	it might possess
		 */
		if (skb->sk)
			skb_set_owner_w(frag, skb->sk);

		/*
		 *	Copy the packet header into the new buffer.
		 */
		skb_copy_from_linear_data(skb, skb_network_header(frag), hlen);

		/*
		 *	Build fragment header.
		 */
		fh->nexthdr = nexthdr;
		fh->reserved = 0;
		if (!frag_id) {
			ipv6_select_ident(fh, rt);
			frag_id = fh->identification;
		} else
			fh->identification = frag_id;

		/*
		 *	Copy a block of the IP datagram.
		 */
		if (skb_copy_bits(skb, ptr, skb_transport_header(frag), len))
			BUG();
		left -= len;

		fh->frag_off = htons(offset);
		if (left > 0)
			fh->frag_off |= htons(IP6_MF);
		ipv6_hdr(frag)->payload_len = htons(frag->len -
						    sizeof(struct ipv6hdr));

		ptr += len;
		offset += len;

		/*
		 *	Put this fragment into the sending queue.
		 */
		err = output(frag);
		if (err)
			goto fail;

		IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
			      IPSTATS_MIB_FRAGCREATES);
	}
	IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
		      IPSTATS_MIB_FRAGOKS);
	kfree_skb(skb);
	return err;

fail:
	IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
		      IPSTATS_MIB_FRAGFAILS);
	kfree_skb(skb);
	return err;
}
Пример #25
0
static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
{
	struct net_device *dev;
	struct sk_buff *frag;
	struct rt6_info *rt = (struct rt6_info*)skb->dst;
	struct ipv6hdr *tmp_hdr;
	struct frag_hdr *fh;
	unsigned int mtu, hlen, left, len;
	u32 frag_id = 0;
	int ptr, offset = 0, err=0;
	u8 *prevhdr, nexthdr = 0;

	dev = rt->u.dst.dev;
	hlen = ip6_find_1stfragopt(skb, &prevhdr);
	nexthdr = *prevhdr;

	mtu = dst_mtu(&rt->u.dst) - hlen - sizeof(struct frag_hdr);

	if (skb_shinfo(skb)->frag_list) {
		int first_len = skb_pagelen(skb);

		if (first_len - hlen > mtu ||
		    ((first_len - hlen) & 7) ||
		    skb_cloned(skb))
			goto slow_path;

		for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
			/* Correct geometry. */
			if (frag->len > mtu ||
			    ((frag->len & 7) && frag->next) ||
			    skb_headroom(frag) < hlen)
			    goto slow_path;

			/* Partially cloned skb? */
			if (skb_shared(frag))
				goto slow_path;

			BUG_ON(frag->sk);
			if (skb->sk) {
				sock_hold(skb->sk);
				frag->sk = skb->sk;
				frag->destructor = sock_wfree;
				skb->truesize -= frag->truesize;
			}
		}

		err = 0;
		offset = 0;
		frag = skb_shinfo(skb)->frag_list;
		skb_shinfo(skb)->frag_list = NULL;
		/* BUILD HEADER */

		tmp_hdr = kmalloc(hlen, GFP_ATOMIC);
		if (!tmp_hdr) {
			IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
			return -ENOMEM;
		}

		*prevhdr = NEXTHDR_FRAGMENT;
		memcpy(tmp_hdr, skb->nh.raw, hlen);
		__skb_pull(skb, hlen);
		fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
		skb->nh.raw = __skb_push(skb, hlen);
		memcpy(skb->nh.raw, tmp_hdr, hlen);

		ipv6_select_ident(skb, fh);
		fh->nexthdr = nexthdr;
		fh->reserved = 0;
		fh->frag_off = htons(IP6_MF);
		frag_id = fh->identification;

		first_len = skb_pagelen(skb);
		skb->data_len = first_len - skb_headlen(skb);
		skb->len = first_len;
		skb->nh.ipv6h->payload_len = htons(first_len - sizeof(struct ipv6hdr));
 

		for (;;) {
			/* Prepare header of the next frame,
			 * before previous one went down. */
			if (frag) {
				frag->ip_summed = CHECKSUM_NONE;
				frag->h.raw = frag->data;
				fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
				frag->nh.raw = __skb_push(frag, hlen);
				memcpy(frag->nh.raw, tmp_hdr, hlen);
				offset += skb->len - hlen - sizeof(struct frag_hdr);
				fh->nexthdr = nexthdr;
				fh->reserved = 0;
				fh->frag_off = htons(offset);
				if (frag->next != NULL)
					fh->frag_off |= htons(IP6_MF);
				fh->identification = frag_id;
				frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
				ip6_copy_metadata(frag, skb);
			}
			
			err = output(skb);
			if (err || !frag)
				break;

			skb = frag;
			frag = skb->next;
			skb->next = NULL;
		}

		if (tmp_hdr)
			kfree(tmp_hdr);

		if (err == 0) {
			IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
			return 0;
		}

		while (frag) {
			skb = frag->next;
			kfree_skb(frag);
			frag = skb;
		}

		IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
		return err;
	}

slow_path:
	left = skb->len - hlen;		/* Space per frame */
	ptr = hlen;			/* Where to start from */

	/*
	 *	Fragment the datagram.
	 */

	*prevhdr = NEXTHDR_FRAGMENT;

	/*
	 *	Keep copying data until we run out.
	 */
	while(left > 0)	{
		len = left;
		/* IF: it doesn't fit, use 'mtu' - the data space left */
		if (len > mtu)
			len = mtu;
		/* IF: we are not sending upto and including the packet end
		   then align the next start on an eight byte boundary */
		if (len < left)	{
			len &= ~7;
		}
		/*
		 *	Allocate buffer.
		 */

		if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) {
			NETDEBUG(printk(KERN_INFO "IPv6: frag: no memory for new fragment!\n"));
			IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
			err = -ENOMEM;
			goto fail;
		}

		/*
		 *	Set up data on packet
		 */

		ip6_copy_metadata(frag, skb);
		skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev));
		skb_put(frag, len + hlen + sizeof(struct frag_hdr));
		frag->nh.raw = frag->data;
		fh = (struct frag_hdr*)(frag->data + hlen);
		frag->h.raw = frag->data + hlen + sizeof(struct frag_hdr);

		/*
		 *	Charge the memory for the fragment to any owner
		 *	it might possess
		 */
		if (skb->sk)
			skb_set_owner_w(frag, skb->sk);

		/*
		 *	Copy the packet header into the new buffer.
		 */
		memcpy(frag->nh.raw, skb->data, hlen);

		/*
		 *	Build fragment header.
		 */
		fh->nexthdr = nexthdr;
		fh->reserved = 0;
		if (frag_id) {
			ipv6_select_ident(skb, fh);
			frag_id = fh->identification;
		} else
			fh->identification = frag_id;

		/*
		 *	Copy a block of the IP datagram.
		 */
		if (skb_copy_bits(skb, ptr, frag->h.raw, len))
			BUG();
		left -= len;

		fh->frag_off = htons(offset);
		if (left > 0)
			fh->frag_off |= htons(IP6_MF);
		frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));

		ptr += len;
		offset += len;

		/*
		 *	Put this fragment into the sending queue.
		 */

		IP6_INC_STATS(IPSTATS_MIB_FRAGCREATES);

		err = output(frag);
		if (err)
			goto fail;
	}
	kfree_skb(skb);
	IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
	return err;

fail:
	kfree_skb(skb); 
	IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
	return err;
}
Пример #26
0
/*
 * xmit an sk_buff (used by TCP, SCTP and DCCP)
 * Note : socket lock is not held for SYNACK packets, but might be modified
 * by calls to skb_set_owner_w() and ipv6_local_error(),
 * which are using proper atomic operations or spinlocks.
 */
int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
	     struct ipv6_txoptions *opt, int tclass)
{
	struct net *net = sock_net(sk);
	const struct ipv6_pinfo *np = inet6_sk(sk);
	struct in6_addr *first_hop = &fl6->daddr;
	struct dst_entry *dst = skb_dst(skb);
	struct ipv6hdr *hdr;
	u8  proto = fl6->flowi6_proto;
	int seg_len = skb->len;
	int hlimit = -1;
	u32 mtu;

	if (opt) {
		unsigned int head_room;

		/* First: exthdrs may take lots of space (~8K for now)
		   MAX_HEADER is not enough.
		 */
		head_room = opt->opt_nflen + opt->opt_flen;
		seg_len += head_room;
		head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);

		if (skb_headroom(skb) < head_room) {
			struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
			if (!skb2) {
				IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
					      IPSTATS_MIB_OUTDISCARDS);
				kfree_skb(skb);
				return -ENOBUFS;
			}
			consume_skb(skb);
			skb = skb2;
			/* skb_set_owner_w() changes sk->sk_wmem_alloc atomically,
			 * it is safe to call in our context (socket lock not held)
			 */
			skb_set_owner_w(skb, (struct sock *)sk);
		}
		if (opt->opt_flen)
			ipv6_push_frag_opts(skb, opt, &proto);
		if (opt->opt_nflen)
			ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
	}

	skb_push(skb, sizeof(struct ipv6hdr));
	skb_reset_network_header(skb);
	hdr = ipv6_hdr(skb);

	/*
	 *	Fill in the IPv6 header
	 */
	if (np)
		hlimit = np->hop_limit;
	if (hlimit < 0)
		hlimit = ip6_dst_hoplimit(dst);

	ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel,
						     np->autoflowlabel, fl6));

	hdr->payload_len = htons(seg_len);
	hdr->nexthdr = proto;
	hdr->hop_limit = hlimit;

	hdr->saddr = fl6->saddr;
	hdr->daddr = *first_hop;

	skb->protocol = htons(ETH_P_IPV6);
	skb->priority = sk->sk_priority;
	skb->mark = sk->sk_mark;

	mtu = dst_mtu(dst);
	if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) {
		IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
			      IPSTATS_MIB_OUT, skb->len);

		/* if egress device is enslaved to an L3 master device pass the
		 * skb to its handler for processing
		 */
		skb = l3mdev_ip6_out((struct sock *)sk, skb);
		if (unlikely(!skb))
			return 0;

		/* hooks should never assume socket lock is held.
		 * we promote our socket to non const
		 */
		return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
			       net, (struct sock *)sk, skb, NULL, dst->dev,
			       dst_output);
	}

	skb->dev = dst->dev;
	/* ipv6_local_error() does not require socket lock,
	 * we promote our socket to non const
	 */
	ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu);

	IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS);
	kfree_skb(skb);
	return -EMSGSIZE;
}
Пример #27
0
static int ip6_finish_output2(struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	struct net_device *dev = dst->dev;
	struct neighbour *neigh;
	int res;

	skb->protocol = htons(ETH_P_IPV6);
	skb->dev = dev;

	if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
		struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));

		if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(skb->sk) &&
		    ((mroute6_socket(dev_net(dev), skb) &&
		     !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
		     ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
					 &ipv6_hdr(skb)->saddr))) {
			struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);

			/* Do not check for IFF_ALLMULTI; multicast routing
			   is not supported in any case.
			 */
			if (newskb)
				NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING,
					newskb, NULL, newskb->dev,
					ip6_dev_loopback_xmit);

			if (ipv6_hdr(skb)->hop_limit == 0) {
				IP6_INC_STATS(dev_net(dev), idev,
					      IPSTATS_MIB_OUTDISCARDS);
				kfree_skb(skb);
				return 0;
			}
		}

		IP6_UPD_PO_STATS(dev_net(dev), idev, IPSTATS_MIB_OUTMCAST,
				skb->len);
	}

	rcu_read_lock();
	if (dst->hh) {
		res = neigh_hh_output(dst->hh, skb);

		rcu_read_unlock();
		return res;
	} else {
		neigh = dst_get_neighbour(dst);
		if (neigh) {
			res = neigh->output(skb);

			rcu_read_unlock();
			return res;
		}
		rcu_read_unlock();
	}

	IP6_INC_STATS_BH(dev_net(dst->dev),
			 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
	kfree_skb(skb);
	return -EINVAL;
}