| /* | 
 |  *	IPv6 output functions | 
 |  *	Linux INET6 implementation | 
 |  * | 
 |  *	Authors: | 
 |  *	Pedro Roque		<[email protected]> | 
 |  * | 
 |  *	Based on linux/net/ipv4/ip_output.c | 
 |  * | 
 |  *	This program is free software; you can redistribute it and/or | 
 |  *      modify it under the terms of the GNU General Public License | 
 |  *      as published by the Free Software Foundation; either version | 
 |  *      2 of the License, or (at your option) any later version. | 
 |  * | 
 |  *	Changes: | 
 |  *	A.N.Kuznetsov	:	airthmetics in fragmentation. | 
 |  *				extension headers are implemented. | 
 |  *				route changes now work. | 
 |  *				ip6_forward does not confuse sniffers. | 
 |  *				etc. | 
 |  * | 
 |  *      H. von Brand    :       Added missing #include <linux/string.h> | 
 |  *	Imran Patel	: 	frag id should be in NBO | 
 |  *      Kazunori MIYAZAWA @USAGI | 
 |  *			:       add ip6_append_data and related functions | 
 |  *				for datagram xmit | 
 |  */ | 
 |  | 
 | #include <linux/errno.h> | 
 | #include <linux/kernel.h> | 
 | #include <linux/string.h> | 
 | #include <linux/socket.h> | 
 | #include <linux/net.h> | 
 | #include <linux/netdevice.h> | 
 | #include <linux/if_arp.h> | 
 | #include <linux/in6.h> | 
 | #include <linux/tcp.h> | 
 | #include <linux/route.h> | 
 | #include <linux/module.h> | 
 | #include <linux/slab.h> | 
 |  | 
 | #include <linux/netfilter.h> | 
 | #include <linux/netfilter_ipv6.h> | 
 |  | 
 | #include <net/sock.h> | 
 | #include <net/snmp.h> | 
 |  | 
 | #include <net/ipv6.h> | 
 | #include <net/ndisc.h> | 
 | #include <net/protocol.h> | 
 | #include <net/ip6_route.h> | 
 | #include <net/addrconf.h> | 
 | #include <net/rawv6.h> | 
 | #include <net/icmp.h> | 
 | #include <net/xfrm.h> | 
 | #include <net/checksum.h> | 
 | #include <linux/mroute6.h> | 
 |  | 
 | int __ip6_local_out(struct sk_buff *skb) | 
 | { | 
 | 	int len; | 
 |  | 
 | 	len = skb->len - sizeof(struct ipv6hdr); | 
 | 	if (len > IPV6_MAXPLEN) | 
 | 		len = 0; | 
 | 	ipv6_hdr(skb)->payload_len = htons(len); | 
 |  | 
 | 	return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, | 
 | 		       skb_dst(skb)->dev, dst_output); | 
 | } | 
 |  | 
 | int ip6_local_out(struct sk_buff *skb) | 
 | { | 
 | 	int err; | 
 |  | 
 | 	err = __ip6_local_out(skb); | 
 | 	if (likely(err == 1)) | 
 | 		err = dst_output(skb); | 
 |  | 
 | 	return err; | 
 | } | 
 | EXPORT_SYMBOL_GPL(ip6_local_out); | 
 |  | 
 | 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, &ipv6_hdr(skb)->daddr); | 
 | 	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_BH(dev_net(dst->dev), | 
 | 			 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); | 
 | 	kfree_skb(skb); | 
 | 	return -EINVAL; | 
 | } | 
 |  | 
 | static int ip6_finish_output(struct sk_buff *skb) | 
 | { | 
 | 	if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) || | 
 | 	    dst_allfrag(skb_dst(skb))) | 
 | 		return ip6_fragment(skb, ip6_finish_output2); | 
 | 	else | 
 | 		return ip6_finish_output2(skb); | 
 | } | 
 |  | 
 | int ip6_output(struct sk_buff *skb) | 
 | { | 
 | 	struct net_device *dev = skb_dst(skb)->dev; | 
 | 	struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); | 
 | 	if (unlikely(idev->cnf.disable_ipv6)) { | 
 | 		IP6_INC_STATS(dev_net(dev), idev, | 
 | 			      IPSTATS_MIB_OUTDISCARDS); | 
 | 		kfree_skb(skb); | 
 | 		return 0; | 
 | 	} | 
 |  | 
 | 	return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL, dev, | 
 | 			    ip6_finish_output, | 
 | 			    !(IP6CB(skb)->flags & IP6SKB_REROUTED)); | 
 | } | 
 |  | 
 | /* | 
 |  *	xmit an sk_buff (used by TCP, SCTP and DCCP) | 
 |  */ | 
 |  | 
 | 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; | 
 | 			} | 
 | 			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, 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); | 
 | 	} | 
 |  | 
 | 	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; | 
 | } | 
 |  | 
 | EXPORT_SYMBOL(ip6_xmit); | 
 |  | 
 | static int ip6_call_ra_chain(struct sk_buff *skb, int sel) | 
 | { | 
 | 	struct ip6_ra_chain *ra; | 
 | 	struct sock *last = NULL; | 
 |  | 
 | 	read_lock(&ip6_ra_lock); | 
 | 	for (ra = ip6_ra_chain; ra; ra = ra->next) { | 
 | 		struct sock *sk = ra->sk; | 
 | 		if (sk && ra->sel == sel && | 
 | 		    (!sk->sk_bound_dev_if || | 
 | 		     sk->sk_bound_dev_if == skb->dev->ifindex)) { | 
 | 			if (last) { | 
 | 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); | 
 | 				if (skb2) | 
 | 					rawv6_rcv(last, skb2); | 
 | 			} | 
 | 			last = sk; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	if (last) { | 
 | 		rawv6_rcv(last, skb); | 
 | 		read_unlock(&ip6_ra_lock); | 
 | 		return 1; | 
 | 	} | 
 | 	read_unlock(&ip6_ra_lock); | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int ip6_forward_proxy_check(struct sk_buff *skb) | 
 | { | 
 | 	struct ipv6hdr *hdr = ipv6_hdr(skb); | 
 | 	u8 nexthdr = hdr->nexthdr; | 
 | 	__be16 frag_off; | 
 | 	int offset; | 
 |  | 
 | 	if (ipv6_ext_hdr(nexthdr)) { | 
 | 		offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off); | 
 | 		if (offset < 0) | 
 | 			return 0; | 
 | 	} else | 
 | 		offset = sizeof(struct ipv6hdr); | 
 |  | 
 | 	if (nexthdr == IPPROTO_ICMPV6) { | 
 | 		struct icmp6hdr *icmp6; | 
 |  | 
 | 		if (!pskb_may_pull(skb, (skb_network_header(skb) + | 
 | 					 offset + 1 - skb->data))) | 
 | 			return 0; | 
 |  | 
 | 		icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset); | 
 |  | 
 | 		switch (icmp6->icmp6_type) { | 
 | 		case NDISC_ROUTER_SOLICITATION: | 
 | 		case NDISC_ROUTER_ADVERTISEMENT: | 
 | 		case NDISC_NEIGHBOUR_SOLICITATION: | 
 | 		case NDISC_NEIGHBOUR_ADVERTISEMENT: | 
 | 		case NDISC_REDIRECT: | 
 | 			/* For reaction involving unicast neighbor discovery | 
 | 			 * message destined to the proxied address, pass it to | 
 | 			 * input function. | 
 | 			 */ | 
 | 			return 1; | 
 | 		default: | 
 | 			break; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	/* | 
 | 	 * The proxying router can't forward traffic sent to a link-local | 
 | 	 * address, so signal the sender and discard the packet. This | 
 | 	 * behavior is clarified by the MIPv6 specification. | 
 | 	 */ | 
 | 	if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) { | 
 | 		dst_link_failure(skb); | 
 | 		return -1; | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static inline int ip6_forward_finish(struct sk_buff *skb) | 
 | { | 
 | 	return dst_output(skb); | 
 | } | 
 |  | 
 | 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 && | 
 | 	    pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) { | 
 | 		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 inet_peer *peer; | 
 | 		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; | 
 |  | 
 | 		peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1); | 
 |  | 
 | 		/* Limit redirects both by destination (here) | 
 | 		   and by source (inside ndisc_send_redirect) | 
 | 		 */ | 
 | 		if (inet_peer_xrlim_allow(peer, 1*HZ)) | 
 | 			ndisc_send_redirect(skb, target); | 
 | 		if (peer) | 
 | 			inet_putpeer(peer); | 
 | 	} 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->local_df && skb->len > mtu && !skb_is_gso(skb)) || | 
 | 	    (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)) { | 
 | 		/* 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); | 
 | 	IP6_ADD_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len); | 
 | 	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; | 
 | } | 
 |  | 
 | static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from) | 
 | { | 
 | 	to->pkt_type = from->pkt_type; | 
 | 	to->priority = from->priority; | 
 | 	to->protocol = from->protocol; | 
 | 	skb_dst_drop(to); | 
 | 	skb_dst_set(to, dst_clone(skb_dst(from))); | 
 | 	to->dev = from->dev; | 
 | 	to->mark = from->mark; | 
 |  | 
 | #ifdef CONFIG_NET_SCHED | 
 | 	to->tc_index = from->tc_index; | 
 | #endif | 
 | 	nf_copy(to, from); | 
 | #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) | 
 | 	to->nf_trace = from->nf_trace; | 
 | #endif | 
 | 	skb_copy_secmark(to, from); | 
 | } | 
 |  | 
 | 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 (unlikely(!skb->local_df && skb->len > mtu) || | 
 | 		     (IP6CB(skb)->frag_max_size && | 
 | 		      IP6CB(skb)->frag_max_size > mtu)) { | 
 | 		if (skb->sk && dst_allfrag(skb_dst(skb))) | 
 | 			sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK); | 
 |  | 
 | 		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); | 
 | 			ip6_rt_put(rt); | 
 | 			return 0; | 
 | 		} | 
 |  | 
 | 		while (frag) { | 
 | 			skb = frag->next; | 
 | 			kfree_skb(frag); | 
 | 			frag = skb; | 
 | 		} | 
 |  | 
 | 		IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), | 
 | 			      IPSTATS_MIB_FRAGFAILS); | 
 | 		ip6_rt_put(rt); | 
 | 		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: | 
 | 	if ((skb->ip_summed == CHECKSUM_PARTIAL) && | 
 | 	    skb_checksum_help(skb)) | 
 | 		goto fail; | 
 |  | 
 | 	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); | 
 | 	consume_skb(skb); | 
 | 	return err; | 
 |  | 
 | fail: | 
 | 	IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | 
 | 		      IPSTATS_MIB_FRAGFAILS); | 
 | 	kfree_skb(skb); | 
 | 	return err; | 
 | } | 
 |  | 
 | static inline int ip6_rt_check(const struct rt6key *rt_key, | 
 | 			       const struct in6_addr *fl_addr, | 
 | 			       const struct in6_addr *addr_cache) | 
 | { | 
 | 	return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && | 
 | 		(addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache)); | 
 | } | 
 |  | 
 | static struct dst_entry *ip6_sk_dst_check(struct sock *sk, | 
 | 					  struct dst_entry *dst, | 
 | 					  const struct flowi6 *fl6) | 
 | { | 
 | 	struct ipv6_pinfo *np = inet6_sk(sk); | 
 | 	struct rt6_info *rt = (struct rt6_info *)dst; | 
 |  | 
 | 	if (!dst) | 
 | 		goto out; | 
 |  | 
 | 	/* 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. ip6_rt_check(): 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 (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) || | 
 | #ifdef CONFIG_IPV6_SUBTREES | 
 | 	    ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) || | 
 | #endif | 
 | 	    (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex)) { | 
 | 		dst_release(dst); | 
 | 		dst = NULL; | 
 | 	} | 
 |  | 
 | out: | 
 | 	return dst; | 
 | } | 
 |  | 
 | 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, &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); | 
 | 			if ((err = (*dst)->error)) | 
 | 				goto out_err_release; | 
 | 		} | 
 | 	} | 
 | #endif | 
 |  | 
 | 	return 0; | 
 |  | 
 | out_err_release: | 
 | 	if (err == -ENETUNREACH) | 
 | 		IP6_INC_STATS_BH(net, NULL, IPSTATS_MIB_OUTNOROUTES); | 
 | 	dst_release(*dst); | 
 | 	*dst = NULL; | 
 | 	return err; | 
 | } | 
 |  | 
 | /** | 
 |  *	ip6_dst_lookup - perform route lookup on flow | 
 |  *	@sk: socket which provides route info | 
 |  *	@dst: pointer to dst_entry * for result | 
 |  *	@fl6: flow to lookup | 
 |  * | 
 |  *	This function performs a route lookup on the given flow. | 
 |  * | 
 |  *	It returns zero on success, or a standard errno code on error. | 
 |  */ | 
 | int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi6 *fl6) | 
 | { | 
 | 	*dst = NULL; | 
 | 	return ip6_dst_lookup_tail(sk, dst, fl6); | 
 | } | 
 | EXPORT_SYMBOL_GPL(ip6_dst_lookup); | 
 |  | 
 | /** | 
 |  *	ip6_dst_lookup_flow - perform route lookup on flow with ipsec | 
 |  *	@sk: socket which provides route info | 
 |  *	@fl6: flow to lookup | 
 |  *	@final_dst: final destination address for ipsec lookup | 
 |  *	@can_sleep: we are in a sleepable context | 
 |  * | 
 |  *	This function performs a route lookup on the given flow. | 
 |  * | 
 |  *	It returns a valid dst pointer on success, or a pointer encoded | 
 |  *	error code. | 
 |  */ | 
 | struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6, | 
 | 				      const struct in6_addr *final_dst, | 
 | 				      bool can_sleep) | 
 | { | 
 | 	struct dst_entry *dst = NULL; | 
 | 	int err; | 
 |  | 
 | 	err = ip6_dst_lookup_tail(sk, &dst, fl6); | 
 | 	if (err) | 
 | 		return ERR_PTR(err); | 
 | 	if (final_dst) | 
 | 		fl6->daddr = *final_dst; | 
 | 	if (can_sleep) | 
 | 		fl6->flowi6_flags |= FLOWI_FLAG_CAN_SLEEP; | 
 |  | 
 | 	return xfrm_lookup(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0); | 
 | } | 
 | EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow); | 
 |  | 
 | /** | 
 |  *	ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow | 
 |  *	@sk: socket which provides the dst cache and route info | 
 |  *	@fl6: flow to lookup | 
 |  *	@final_dst: final destination address for ipsec lookup | 
 |  *	@can_sleep: we are in a sleepable context | 
 |  * | 
 |  *	This function performs a route lookup on the given flow with the | 
 |  *	possibility of using the cached route in the socket if it is valid. | 
 |  *	It will take the socket dst lock when operating on the dst cache. | 
 |  *	As a result, this function can only be used in process context. | 
 |  * | 
 |  *	It returns a valid dst pointer on success, or a pointer encoded | 
 |  *	error code. | 
 |  */ | 
 | struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6, | 
 | 					 const struct in6_addr *final_dst, | 
 | 					 bool can_sleep) | 
 | { | 
 | 	struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); | 
 | 	int err; | 
 |  | 
 | 	dst = ip6_sk_dst_check(sk, dst, fl6); | 
 |  | 
 | 	err = ip6_dst_lookup_tail(sk, &dst, fl6); | 
 | 	if (err) | 
 | 		return ERR_PTR(err); | 
 | 	if (final_dst) | 
 | 		fl6->daddr = *final_dst; | 
 | 	if (can_sleep) | 
 | 		fl6->flowi6_flags |= FLOWI_FLAG_CAN_SLEEP; | 
 |  | 
 | 	return xfrm_lookup(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0); | 
 | } | 
 | EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow); | 
 |  | 
 | static inline int ip6_ufo_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 hh_len, int fragheaderlen, | 
 | 			int transhdrlen, int mtu,unsigned int flags, | 
 | 			struct rt6_info *rt) | 
 |  | 
 | { | 
 | 	struct sk_buff *skb; | 
 | 	int err; | 
 |  | 
 | 	/* There is support for UDP large send offload by network | 
 | 	 * device, so create one single skb packet containing complete | 
 | 	 * udp datagram | 
 | 	 */ | 
 | 	if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { | 
 | 		skb = sock_alloc_send_skb(sk, | 
 | 			hh_len + fragheaderlen + transhdrlen + 20, | 
 | 			(flags & MSG_DONTWAIT), &err); | 
 | 		if (skb == NULL) | 
 | 			return err; | 
 |  | 
 | 		/* reserve space for Hardware header */ | 
 | 		skb_reserve(skb, hh_len); | 
 |  | 
 | 		/* create space for UDP/IP header */ | 
 | 		skb_put(skb,fragheaderlen + transhdrlen); | 
 |  | 
 | 		/* initialize network header pointer */ | 
 | 		skb_reset_network_header(skb); | 
 |  | 
 | 		/* initialize protocol header pointer */ | 
 | 		skb->transport_header = skb->network_header + fragheaderlen; | 
 |  | 
 | 		skb->ip_summed = CHECKSUM_PARTIAL; | 
 | 		skb->csum = 0; | 
 | 	} | 
 |  | 
 | 	err = skb_append_datato_frags(sk,skb, getfrag, from, | 
 | 				      (length - transhdrlen)); | 
 | 	if (!err) { | 
 | 		struct frag_hdr fhdr; | 
 |  | 
 | 		/* Specify the length of each IPv6 datagram fragment. | 
 | 		 * It has to be a multiple of 8. | 
 | 		 */ | 
 | 		skb_shinfo(skb)->gso_size = (mtu - fragheaderlen - | 
 | 					     sizeof(struct frag_hdr)) & ~7; | 
 | 		skb_shinfo(skb)->gso_type = SKB_GSO_UDP; | 
 | 		ipv6_select_ident(&fhdr, rt); | 
 | 		skb_shinfo(skb)->ip6_frag_id = fhdr.identification; | 
 | 		__skb_queue_tail(&sk->sk_write_queue, skb); | 
 |  | 
 | 		return 0; | 
 | 	} | 
 | 	/* There is not enough support do UPD LSO, | 
 | 	 * so follow normal path | 
 | 	 */ | 
 | 	kfree_skb(skb); | 
 |  | 
 | 	return err; | 
 | } | 
 |  | 
 | static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src, | 
 | 					       gfp_t gfp) | 
 | { | 
 | 	return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; | 
 | } | 
 |  | 
 | static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src, | 
 | 						gfp_t gfp) | 
 | { | 
 | 	return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; | 
 | } | 
 |  | 
 | static void ip6_append_data_mtu(int *mtu, | 
 | 				int *maxfraglen, | 
 | 				unsigned int fragheaderlen, | 
 | 				struct sk_buff *skb, | 
 | 				struct rt6_info *rt) | 
 | { | 
 | 	if (!(rt->dst.flags & DST_XFRM_TUNNEL)) { | 
 | 		if (skb == NULL) { | 
 | 			/* first fragment, reserve header_len */ | 
 | 			*mtu = *mtu - rt->dst.header_len; | 
 |  | 
 | 		} else { | 
 | 			/* | 
 | 			 * this fragment is not first, the headers | 
 | 			 * space is regarded as data space. | 
 | 			 */ | 
 | 			*mtu = dst_mtu(rt->dst.path); | 
 | 		} | 
 | 		*maxfraglen = ((*mtu - fragheaderlen) & ~7) | 
 | 			      + fragheaderlen - sizeof(struct frag_hdr); | 
 | 	} | 
 | } | 
 |  | 
 | 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; | 
 | 	int exthdrlen; | 
 | 	int dst_exthdrlen; | 
 | 	int hh_len; | 
 | 	int mtu; | 
 | 	int copy; | 
 | 	int err; | 
 | 	int offset = 0; | 
 | 	__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; | 
 | 		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; | 
 | 	} | 
 |  | 
 | 	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) | 
 | 		sock_tx_timestamp(sk, &tx_flags); | 
 |  | 
 | 	/* | 
 | 	 * 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) { | 
 | 		int proto = sk->sk_protocol; | 
 | 		if (dontfrag && (proto == IPPROTO_UDP || proto == IPPROTO_RAW)){ | 
 | 			ipv6_local_rxpmtu(sk, fl6, mtu-exthdrlen); | 
 | 			return -EMSGSIZE; | 
 | 		} | 
 |  | 
 | 		if (proto == 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 = 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 = (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); | 
 |  | 
 | 			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 = CHECKSUM_NONE; | 
 | 			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; | 
 |  | 
 | 			/* | 
 | 			 * 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; | 
 | 			struct page_frag *pfrag = sk_page_frag(sk); | 
 |  | 
 | 			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; | 
 | } | 
 | EXPORT_SYMBOL_GPL(ip6_append_data); | 
 |  | 
 | static void ip6_cork_release(struct inet_sock *inet, struct ipv6_pinfo *np) | 
 | { | 
 | 	if (np->cork.opt) { | 
 | 		kfree(np->cork.opt->dst0opt); | 
 | 		kfree(np->cork.opt->dst1opt); | 
 | 		kfree(np->cork.opt->hopopt); | 
 | 		kfree(np->cork.opt->srcrt); | 
 | 		kfree(np->cork.opt); | 
 | 		np->cork.opt = NULL; | 
 | 	} | 
 |  | 
 | 	if (inet->cork.base.dst) { | 
 | 		dst_release(inet->cork.base.dst); | 
 | 		inet->cork.base.dst = NULL; | 
 | 		inet->cork.base.flags &= ~IPCORK_ALLFRAG; | 
 | 	} | 
 | 	memset(&inet->cork.fl, 0, sizeof(inet->cork.fl)); | 
 | } | 
 |  | 
 | 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); | 
 |  | 
 | 	ip6_flow_hdr(hdr, np->cork.tclass, fl6->flowlabel); | 
 | 	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_BH(net, idev, icmp6_hdr(skb)->icmp6_type); | 
 | 		ICMP6_INC_STATS_BH(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; | 
 | } | 
 | EXPORT_SYMBOL_GPL(ip6_push_pending_frames); | 
 |  | 
 | void ip6_flush_pending_frames(struct sock *sk) | 
 | { | 
 | 	struct sk_buff *skb; | 
 |  | 
 | 	while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) { | 
 | 		if (skb_dst(skb)) | 
 | 			IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)), | 
 | 				      IPSTATS_MIB_OUTDISCARDS); | 
 | 		kfree_skb(skb); | 
 | 	} | 
 |  | 
 | 	ip6_cork_release(inet_sk(sk), inet6_sk(sk)); | 
 | } | 
 | EXPORT_SYMBOL_GPL(ip6_flush_pending_frames); |