2 * IPv6 output functions
3 * Linux INET6 implementation
6 * Pedro Roque <roque@di.fc.ul.pt>
8 * Based on linux/net/ipv4/ip_output.c
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
16 * A.N.Kuznetsov : airthmetics in fragmentation.
17 * extension headers are implemented.
18 * route changes now work.
19 * ip6_forward does not confuse sniffers.
22 * H. von Brand : Added missing #include <linux/string.h>
23 * Imran Patel : frag id should be in NBO
24 * Kazunori MIYAZAWA @USAGI
25 * : add ip6_append_data and related functions
29 #include <linux/errno.h>
30 #include <linux/kernel.h>
31 #include <linux/string.h>
32 #include <linux/socket.h>
33 #include <linux/net.h>
34 #include <linux/netdevice.h>
35 #include <linux/if_arp.h>
36 #include <linux/in6.h>
37 #include <linux/tcp.h>
38 #include <linux/route.h>
39 #include <linux/module.h>
40 #include <linux/slab.h>
42 #include <linux/netfilter.h>
43 #include <linux/netfilter_ipv6.h>
49 #include <net/ndisc.h>
50 #include <net/protocol.h>
51 #include <net/ip6_route.h>
52 #include <net/addrconf.h>
53 #include <net/rawv6.h>
56 #include <net/checksum.h>
57 #include <linux/mroute6.h>
59 int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
61 int __ip6_local_out(struct sk_buff *skb)
65 len = skb->len - sizeof(struct ipv6hdr);
66 if (len > IPV6_MAXPLEN)
68 ipv6_hdr(skb)->payload_len = htons(len);
70 return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL,
71 skb_dst(skb)->dev, dst_output);
74 int ip6_local_out(struct sk_buff *skb)
78 err = __ip6_local_out(skb);
80 err = dst_output(skb);
84 EXPORT_SYMBOL_GPL(ip6_local_out);
86 /* dev_loopback_xmit for use with netfilter. */
87 static int ip6_dev_loopback_xmit(struct sk_buff *newskb)
89 skb_reset_mac_header(newskb);
90 __skb_pull(newskb, skb_network_offset(newskb));
91 newskb->pkt_type = PACKET_LOOPBACK;
92 newskb->ip_summed = CHECKSUM_UNNECESSARY;
93 WARN_ON(!skb_dst(newskb));
99 static int ip6_finish_output2(struct sk_buff *skb)
101 struct dst_entry *dst = skb_dst(skb);
102 struct net_device *dev = dst->dev;
103 struct neighbour *neigh;
105 skb->protocol = htons(ETH_P_IPV6);
108 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
109 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
111 if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(skb->sk) &&
112 ((mroute6_socket(dev_net(dev), skb) &&
113 !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
114 ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
115 &ipv6_hdr(skb)->saddr))) {
116 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
118 /* Do not check for IFF_ALLMULTI; multicast routing
119 is not supported in any case.
122 NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING,
123 newskb, NULL, newskb->dev,
124 ip6_dev_loopback_xmit);
126 if (ipv6_hdr(skb)->hop_limit == 0) {
127 IP6_INC_STATS(dev_net(dev), idev,
128 IPSTATS_MIB_OUTDISCARDS);
134 IP6_UPD_PO_STATS(dev_net(dev), idev, IPSTATS_MIB_OUTMCAST,
138 neigh = dst_get_neighbour(dst);
140 return neigh_output(neigh, skb);
142 IP6_INC_STATS_BH(dev_net(dst->dev),
143 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
148 static int ip6_finish_output(struct sk_buff *skb)
150 if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
151 dst_allfrag(skb_dst(skb)))
152 return ip6_fragment(skb, ip6_finish_output2);
154 return ip6_finish_output2(skb);
157 int ip6_output(struct sk_buff *skb)
159 struct net_device *dev = skb_dst(skb)->dev;
160 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
161 if (unlikely(idev->cnf.disable_ipv6)) {
162 IP6_INC_STATS(dev_net(dev), idev,
163 IPSTATS_MIB_OUTDISCARDS);
168 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL, dev,
170 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
174 * xmit an sk_buff (used by TCP, SCTP and DCCP)
177 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
178 struct ipv6_txoptions *opt)
180 struct net *net = sock_net(sk);
181 struct ipv6_pinfo *np = inet6_sk(sk);
182 struct in6_addr *first_hop = &fl6->daddr;
183 struct dst_entry *dst = skb_dst(skb);
185 u8 proto = fl6->flowi6_proto;
186 int seg_len = skb->len;
192 unsigned int head_room;
194 /* First: exthdrs may take lots of space (~8K for now)
195 MAX_HEADER is not enough.
197 head_room = opt->opt_nflen + opt->opt_flen;
198 seg_len += head_room;
199 head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
201 if (skb_headroom(skb) < head_room) {
202 struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
204 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
205 IPSTATS_MIB_OUTDISCARDS);
211 skb_set_owner_w(skb, sk);
214 ipv6_push_frag_opts(skb, opt, &proto);
216 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
219 skb_push(skb, sizeof(struct ipv6hdr));
220 skb_reset_network_header(skb);
224 * Fill in the IPv6 header
228 hlimit = np->hop_limit;
231 hlimit = ip6_dst_hoplimit(dst);
233 *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl6->flowlabel;
235 hdr->payload_len = htons(seg_len);
236 hdr->nexthdr = proto;
237 hdr->hop_limit = hlimit;
239 ipv6_addr_copy(&hdr->saddr, &fl6->saddr);
240 ipv6_addr_copy(&hdr->daddr, first_hop);
242 skb->priority = sk->sk_priority;
243 skb->mark = sk->sk_mark;
246 if ((skb->len <= mtu) || skb->local_df || skb_is_gso(skb)) {
247 IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
248 IPSTATS_MIB_OUT, skb->len);
249 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL,
250 dst->dev, dst_output);
254 printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n");
256 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
257 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS);
262 EXPORT_SYMBOL(ip6_xmit);
265 * To avoid extra problems ND packets are send through this
266 * routine. It's code duplication but I really want to avoid
267 * extra checks since ipv6_build_header is used by TCP (which
268 * is for us performance critical)
271 int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev,
272 const struct in6_addr *saddr, const struct in6_addr *daddr,
275 struct ipv6_pinfo *np = inet6_sk(sk);
278 skb->protocol = htons(ETH_P_IPV6);
281 skb_reset_network_header(skb);
282 skb_put(skb, sizeof(struct ipv6hdr));
285 *(__be32*)hdr = htonl(0x60000000);
287 hdr->payload_len = htons(len);
288 hdr->nexthdr = proto;
289 hdr->hop_limit = np->hop_limit;
291 ipv6_addr_copy(&hdr->saddr, saddr);
292 ipv6_addr_copy(&hdr->daddr, daddr);
297 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
299 struct ip6_ra_chain *ra;
300 struct sock *last = NULL;
302 read_lock(&ip6_ra_lock);
303 for (ra = ip6_ra_chain; ra; ra = ra->next) {
304 struct sock *sk = ra->sk;
305 if (sk && ra->sel == sel &&
306 (!sk->sk_bound_dev_if ||
307 sk->sk_bound_dev_if == skb->dev->ifindex)) {
309 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
311 rawv6_rcv(last, skb2);
318 rawv6_rcv(last, skb);
319 read_unlock(&ip6_ra_lock);
322 read_unlock(&ip6_ra_lock);
326 static int ip6_forward_proxy_check(struct sk_buff *skb)
328 struct ipv6hdr *hdr = ipv6_hdr(skb);
329 u8 nexthdr = hdr->nexthdr;
332 if (ipv6_ext_hdr(nexthdr)) {
333 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr);
337 offset = sizeof(struct ipv6hdr);
339 if (nexthdr == IPPROTO_ICMPV6) {
340 struct icmp6hdr *icmp6;
342 if (!pskb_may_pull(skb, (skb_network_header(skb) +
343 offset + 1 - skb->data)))
346 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
348 switch (icmp6->icmp6_type) {
349 case NDISC_ROUTER_SOLICITATION:
350 case NDISC_ROUTER_ADVERTISEMENT:
351 case NDISC_NEIGHBOUR_SOLICITATION:
352 case NDISC_NEIGHBOUR_ADVERTISEMENT:
354 /* For reaction involving unicast neighbor discovery
355 * message destined to the proxied address, pass it to
365 * The proxying router can't forward traffic sent to a link-local
366 * address, so signal the sender and discard the packet. This
367 * behavior is clarified by the MIPv6 specification.
369 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
370 dst_link_failure(skb);
377 static inline int ip6_forward_finish(struct sk_buff *skb)
379 return dst_output(skb);
382 int ip6_forward(struct sk_buff *skb)
384 struct dst_entry *dst = skb_dst(skb);
385 struct ipv6hdr *hdr = ipv6_hdr(skb);
386 struct inet6_skb_parm *opt = IP6CB(skb);
387 struct net *net = dev_net(dst->dev);
391 if (net->ipv6.devconf_all->forwarding == 0)
394 if (skb_warn_if_lro(skb))
397 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
398 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
402 if (skb->pkt_type != PACKET_HOST)
405 skb_forward_csum(skb);
408 * We DO NOT make any processing on
409 * RA packets, pushing them to user level AS IS
410 * without ane WARRANTY that application will be able
411 * to interpret them. The reason is that we
412 * cannot make anything clever here.
414 * We are not end-node, so that if packet contains
415 * AH/ESP, we cannot make anything.
416 * Defragmentation also would be mistake, RA packets
417 * cannot be fragmented, because there is no warranty
418 * that different fragments will go along one path. --ANK
421 u8 *ptr = skb_network_header(skb) + opt->ra;
422 if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
427 * check and decrement ttl
429 if (hdr->hop_limit <= 1) {
430 /* Force OUTPUT device used as source address */
432 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0);
433 IP6_INC_STATS_BH(net,
434 ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
440 /* XXX: idev->cnf.proxy_ndp? */
441 if (net->ipv6.devconf_all->proxy_ndp &&
442 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) {
443 int proxied = ip6_forward_proxy_check(skb);
445 return ip6_input(skb);
446 else if (proxied < 0) {
447 IP6_INC_STATS(net, ip6_dst_idev(dst),
448 IPSTATS_MIB_INDISCARDS);
453 if (!xfrm6_route_forward(skb)) {
454 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
459 /* IPv6 specs say nothing about it, but it is clear that we cannot
460 send redirects to source routed frames.
461 We don't send redirects to frames decapsulated from IPsec.
463 n = dst_get_neighbour(dst);
464 if (skb->dev == dst->dev && n && opt->srcrt == 0 && !skb_sec_path(skb)) {
465 struct in6_addr *target = NULL;
469 * incoming and outgoing devices are the same
473 rt = (struct rt6_info *) dst;
474 if ((rt->rt6i_flags & RTF_GATEWAY))
475 target = (struct in6_addr*)&n->primary_key;
477 target = &hdr->daddr;
480 rt6_bind_peer(rt, 1);
482 /* Limit redirects both by destination (here)
483 and by source (inside ndisc_send_redirect)
485 if (inet_peer_xrlim_allow(rt->rt6i_peer, 1*HZ))
486 ndisc_send_redirect(skb, n, target);
488 int addrtype = ipv6_addr_type(&hdr->saddr);
490 /* This check is security critical. */
491 if (addrtype == IPV6_ADDR_ANY ||
492 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK))
494 if (addrtype & IPV6_ADDR_LINKLOCAL) {
495 icmpv6_send(skb, ICMPV6_DEST_UNREACH,
496 ICMPV6_NOT_NEIGHBOUR, 0);
502 if (mtu < IPV6_MIN_MTU)
505 if (skb->len > mtu && !skb_is_gso(skb)) {
506 /* Again, force OUTPUT device used as source address */
508 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
509 IP6_INC_STATS_BH(net,
510 ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS);
511 IP6_INC_STATS_BH(net,
512 ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS);
517 if (skb_cow(skb, dst->dev->hard_header_len)) {
518 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS);
524 /* Mangling hops number delayed to point after skb COW */
528 IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
529 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, skb, skb->dev, dst->dev,
533 IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
539 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
541 to->pkt_type = from->pkt_type;
542 to->priority = from->priority;
543 to->protocol = from->protocol;
545 skb_dst_set(to, dst_clone(skb_dst(from)));
547 to->mark = from->mark;
549 #ifdef CONFIG_NET_SCHED
550 to->tc_index = from->tc_index;
553 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
554 defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
555 to->nf_trace = from->nf_trace;
557 skb_copy_secmark(to, from);
560 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
562 u16 offset = sizeof(struct ipv6hdr);
563 struct ipv6_opt_hdr *exthdr =
564 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
565 unsigned int packet_len = skb->tail - skb->network_header;
567 *nexthdr = &ipv6_hdr(skb)->nexthdr;
569 while (offset + 1 <= packet_len) {
575 case NEXTHDR_ROUTING:
579 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
580 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
590 offset += ipv6_optlen(exthdr);
591 *nexthdr = &exthdr->nexthdr;
592 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
599 int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
601 struct sk_buff *frag;
602 struct rt6_info *rt = (struct rt6_info*)skb_dst(skb);
603 struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
604 struct ipv6hdr *tmp_hdr;
606 unsigned int mtu, hlen, left, len;
608 int ptr, offset = 0, err=0;
609 u8 *prevhdr, nexthdr = 0;
610 struct net *net = dev_net(skb_dst(skb)->dev);
612 hlen = ip6_find_1stfragopt(skb, &prevhdr);
615 mtu = ip6_skb_dst_mtu(skb);
617 /* We must not fragment if the socket is set to force MTU discovery
618 * or if the skb it not generated by a local socket.
620 if (!skb->local_df && skb->len > mtu) {
621 skb->dev = skb_dst(skb)->dev;
622 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
623 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
624 IPSTATS_MIB_FRAGFAILS);
629 if (np && np->frag_size < mtu) {
633 mtu -= hlen + sizeof(struct frag_hdr);
635 if (skb_has_frag_list(skb)) {
636 int first_len = skb_pagelen(skb);
637 struct sk_buff *frag2;
639 if (first_len - hlen > mtu ||
640 ((first_len - hlen) & 7) ||
644 skb_walk_frags(skb, frag) {
645 /* Correct geometry. */
646 if (frag->len > mtu ||
647 ((frag->len & 7) && frag->next) ||
648 skb_headroom(frag) < hlen)
649 goto slow_path_clean;
651 /* Partially cloned skb? */
652 if (skb_shared(frag))
653 goto slow_path_clean;
658 frag->destructor = sock_wfree;
660 skb->truesize -= frag->truesize;
665 frag = skb_shinfo(skb)->frag_list;
666 skb_frag_list_init(skb);
669 *prevhdr = NEXTHDR_FRAGMENT;
670 tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
672 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
673 IPSTATS_MIB_FRAGFAILS);
677 __skb_pull(skb, hlen);
678 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
679 __skb_push(skb, hlen);
680 skb_reset_network_header(skb);
681 memcpy(skb_network_header(skb), tmp_hdr, hlen);
683 ipv6_select_ident(fh);
684 fh->nexthdr = nexthdr;
686 fh->frag_off = htons(IP6_MF);
687 frag_id = fh->identification;
689 first_len = skb_pagelen(skb);
690 skb->data_len = first_len - skb_headlen(skb);
691 skb->len = first_len;
692 ipv6_hdr(skb)->payload_len = htons(first_len -
693 sizeof(struct ipv6hdr));
698 /* Prepare header of the next frame,
699 * before previous one went down. */
701 frag->ip_summed = CHECKSUM_NONE;
702 skb_reset_transport_header(frag);
703 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
704 __skb_push(frag, hlen);
705 skb_reset_network_header(frag);
706 memcpy(skb_network_header(frag), tmp_hdr,
708 offset += skb->len - hlen - sizeof(struct frag_hdr);
709 fh->nexthdr = nexthdr;
711 fh->frag_off = htons(offset);
712 if (frag->next != NULL)
713 fh->frag_off |= htons(IP6_MF);
714 fh->identification = frag_id;
715 ipv6_hdr(frag)->payload_len =
717 sizeof(struct ipv6hdr));
718 ip6_copy_metadata(frag, skb);
723 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
724 IPSTATS_MIB_FRAGCREATES);
737 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
738 IPSTATS_MIB_FRAGOKS);
739 dst_release(&rt->dst);
749 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
750 IPSTATS_MIB_FRAGFAILS);
751 dst_release(&rt->dst);
755 skb_walk_frags(skb, frag2) {
759 frag2->destructor = NULL;
760 skb->truesize += frag2->truesize;
765 left = skb->len - hlen; /* Space per frame */
766 ptr = hlen; /* Where to start from */
769 * Fragment the datagram.
772 *prevhdr = NEXTHDR_FRAGMENT;
775 * Keep copying data until we run out.
779 /* IF: it doesn't fit, use 'mtu' - the data space left */
782 /* IF: we are not sending up to and including the packet end
783 then align the next start on an eight byte boundary */
791 if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_ALLOCATED_SPACE(rt->dst.dev), GFP_ATOMIC)) == NULL) {
792 NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
793 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
794 IPSTATS_MIB_FRAGFAILS);
800 * Set up data on packet
803 ip6_copy_metadata(frag, skb);
804 skb_reserve(frag, LL_RESERVED_SPACE(rt->dst.dev));
805 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
806 skb_reset_network_header(frag);
807 fh = (struct frag_hdr *)(skb_network_header(frag) + hlen);
808 frag->transport_header = (frag->network_header + hlen +
809 sizeof(struct frag_hdr));
812 * Charge the memory for the fragment to any owner
816 skb_set_owner_w(frag, skb->sk);
819 * Copy the packet header into the new buffer.
821 skb_copy_from_linear_data(skb, skb_network_header(frag), hlen);
824 * Build fragment header.
826 fh->nexthdr = nexthdr;
829 ipv6_select_ident(fh);
830 frag_id = fh->identification;
832 fh->identification = frag_id;
835 * Copy a block of the IP datagram.
837 if (skb_copy_bits(skb, ptr, skb_transport_header(frag), len))
841 fh->frag_off = htons(offset);
843 fh->frag_off |= htons(IP6_MF);
844 ipv6_hdr(frag)->payload_len = htons(frag->len -
845 sizeof(struct ipv6hdr));
851 * Put this fragment into the sending queue.
857 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
858 IPSTATS_MIB_FRAGCREATES);
860 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
861 IPSTATS_MIB_FRAGOKS);
866 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
867 IPSTATS_MIB_FRAGFAILS);
872 static inline int ip6_rt_check(const struct rt6key *rt_key,
873 const struct in6_addr *fl_addr,
874 const struct in6_addr *addr_cache)
876 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
877 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache));
880 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
881 struct dst_entry *dst,
882 const struct flowi6 *fl6)
884 struct ipv6_pinfo *np = inet6_sk(sk);
885 struct rt6_info *rt = (struct rt6_info *)dst;
890 /* Yes, checking route validity in not connected
891 * case is not very simple. Take into account,
892 * that we do not support routing by source, TOS,
893 * and MSG_DONTROUTE --ANK (980726)
895 * 1. ip6_rt_check(): If route was host route,
896 * check that cached destination is current.
897 * If it is network route, we still may
898 * check its validity using saved pointer
899 * to the last used address: daddr_cache.
900 * We do not want to save whole address now,
901 * (because main consumer of this service
902 * is tcp, which has not this problem),
903 * so that the last trick works only on connected
905 * 2. oif also should be the same.
907 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) ||
908 #ifdef CONFIG_IPV6_SUBTREES
909 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) ||
911 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex)) {
920 static int ip6_dst_lookup_tail(struct sock *sk,
921 struct dst_entry **dst, struct flowi6 *fl6)
923 struct net *net = sock_net(sk);
924 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
930 *dst = ip6_route_output(net, sk, fl6);
932 if ((err = (*dst)->error))
933 goto out_err_release;
935 if (ipv6_addr_any(&fl6->saddr)) {
936 struct rt6_info *rt = (struct rt6_info *) *dst;
937 err = ip6_route_get_saddr(net, rt, &fl6->daddr,
938 sk ? inet6_sk(sk)->srcprefs : 0,
941 goto out_err_release;
944 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
946 * Here if the dst entry we've looked up
947 * has a neighbour entry that is in the INCOMPLETE
948 * state and the src address from the flow is
949 * marked as OPTIMISTIC, we release the found
950 * dst entry and replace it instead with the
951 * dst entry of the nexthop router
953 n = dst_get_neighbour(*dst);
954 if (n && !(n->nud_state & NUD_VALID)) {
955 struct inet6_ifaddr *ifp;
956 struct flowi6 fl_gw6;
959 ifp = ipv6_get_ifaddr(net, &fl6->saddr,
962 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
968 * We need to get the dst entry for the
969 * default router instead
972 memcpy(&fl_gw6, fl6, sizeof(struct flowi6));
973 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr));
974 *dst = ip6_route_output(net, sk, &fl_gw6);
975 if ((err = (*dst)->error))
976 goto out_err_release;
984 if (err == -ENETUNREACH)
985 IP6_INC_STATS_BH(net, NULL, IPSTATS_MIB_OUTNOROUTES);
992 * ip6_dst_lookup - perform route lookup on flow
993 * @sk: socket which provides route info
994 * @dst: pointer to dst_entry * for result
995 * @fl6: flow to lookup
997 * This function performs a route lookup on the given flow.
999 * It returns zero on success, or a standard errno code on error.
1001 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi6 *fl6)
1004 return ip6_dst_lookup_tail(sk, dst, fl6);
1006 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
1009 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec
1010 * @sk: socket which provides route info
1011 * @fl6: flow to lookup
1012 * @final_dst: final destination address for ipsec lookup
1013 * @can_sleep: we are in a sleepable context
1015 * This function performs a route lookup on the given flow.
1017 * It returns a valid dst pointer on success, or a pointer encoded
1020 struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1021 const struct in6_addr *final_dst,
1024 struct dst_entry *dst = NULL;
1027 err = ip6_dst_lookup_tail(sk, &dst, fl6);
1029 return ERR_PTR(err);
1031 ipv6_addr_copy(&fl6->daddr, final_dst);
1033 fl6->flowi6_flags |= FLOWI_FLAG_CAN_SLEEP;
1035 return xfrm_lookup(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
1037 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
1040 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow
1041 * @sk: socket which provides the dst cache and route info
1042 * @fl6: flow to lookup
1043 * @final_dst: final destination address for ipsec lookup
1044 * @can_sleep: we are in a sleepable context
1046 * This function performs a route lookup on the given flow with the
1047 * possibility of using the cached route in the socket if it is valid.
1048 * It will take the socket dst lock when operating on the dst cache.
1049 * As a result, this function can only be used in process context.
1051 * It returns a valid dst pointer on success, or a pointer encoded
1054 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1055 const struct in6_addr *final_dst,
1058 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
1061 dst = ip6_sk_dst_check(sk, dst, fl6);
1063 err = ip6_dst_lookup_tail(sk, &dst, fl6);
1065 return ERR_PTR(err);
1067 ipv6_addr_copy(&fl6->daddr, final_dst);
1069 fl6->flowi6_flags |= FLOWI_FLAG_CAN_SLEEP;
1071 return xfrm_lookup(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
1073 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow);
1075 static inline int ip6_ufo_append_data(struct sock *sk,
1076 int getfrag(void *from, char *to, int offset, int len,
1077 int odd, struct sk_buff *skb),
1078 void *from, int length, int hh_len, int fragheaderlen,
1079 int transhdrlen, int mtu,unsigned int flags)
1082 struct sk_buff *skb;
1085 /* There is support for UDP large send offload by network
1086 * device, so create one single skb packet containing complete
1089 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
1090 skb = sock_alloc_send_skb(sk,
1091 hh_len + fragheaderlen + transhdrlen + 20,
1092 (flags & MSG_DONTWAIT), &err);
1096 /* reserve space for Hardware header */
1097 skb_reserve(skb, hh_len);
1099 /* create space for UDP/IP header */
1100 skb_put(skb,fragheaderlen + transhdrlen);
1102 /* initialize network header pointer */
1103 skb_reset_network_header(skb);
1105 /* initialize protocol header pointer */
1106 skb->transport_header = skb->network_header + fragheaderlen;
1108 skb->ip_summed = CHECKSUM_PARTIAL;
1112 err = skb_append_datato_frags(sk,skb, getfrag, from,
1113 (length - transhdrlen));
1115 struct frag_hdr fhdr;
1117 /* Specify the length of each IPv6 datagram fragment.
1118 * It has to be a multiple of 8.
1120 skb_shinfo(skb)->gso_size = (mtu - fragheaderlen -
1121 sizeof(struct frag_hdr)) & ~7;
1122 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1123 ipv6_select_ident(&fhdr);
1124 skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
1125 __skb_queue_tail(&sk->sk_write_queue, skb);
1129 /* There is not enough support do UPD LSO,
1130 * so follow normal path
1137 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src,
1140 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1143 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src,
1146 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1149 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
1150 int offset, int len, int odd, struct sk_buff *skb),
1151 void *from, int length, int transhdrlen,
1152 int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
1153 struct rt6_info *rt, unsigned int flags, int dontfrag)
1155 struct inet_sock *inet = inet_sk(sk);
1156 struct ipv6_pinfo *np = inet6_sk(sk);
1157 struct inet_cork *cork;
1158 struct sk_buff *skb;
1159 unsigned int maxfraglen, fragheaderlen;
1166 int csummode = CHECKSUM_NONE;
1169 if (flags&MSG_PROBE)
1171 cork = &inet->cork.base;
1172 if (skb_queue_empty(&sk->sk_write_queue)) {
1177 if (WARN_ON(np->cork.opt))
1180 np->cork.opt = kmalloc(opt->tot_len, sk->sk_allocation);
1181 if (unlikely(np->cork.opt == NULL))
1184 np->cork.opt->tot_len = opt->tot_len;
1185 np->cork.opt->opt_flen = opt->opt_flen;
1186 np->cork.opt->opt_nflen = opt->opt_nflen;
1188 np->cork.opt->dst0opt = ip6_opt_dup(opt->dst0opt,
1190 if (opt->dst0opt && !np->cork.opt->dst0opt)
1193 np->cork.opt->dst1opt = ip6_opt_dup(opt->dst1opt,
1195 if (opt->dst1opt && !np->cork.opt->dst1opt)
1198 np->cork.opt->hopopt = ip6_opt_dup(opt->hopopt,
1200 if (opt->hopopt && !np->cork.opt->hopopt)
1203 np->cork.opt->srcrt = ip6_rthdr_dup(opt->srcrt,
1205 if (opt->srcrt && !np->cork.opt->srcrt)
1208 /* need source address above miyazawa*/
1211 cork->dst = &rt->dst;
1212 inet->cork.fl.u.ip6 = *fl6;
1213 np->cork.hop_limit = hlimit;
1214 np->cork.tclass = tclass;
1215 mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
1216 rt->dst.dev->mtu : dst_mtu(rt->dst.path);
1217 if (np->frag_size < mtu) {
1219 mtu = np->frag_size;
1221 cork->fragsize = mtu;
1222 if (dst_allfrag(rt->dst.path))
1223 cork->flags |= IPCORK_ALLFRAG;
1225 sk->sk_sndmsg_page = NULL;
1226 sk->sk_sndmsg_off = 0;
1227 exthdrlen = rt->dst.header_len + (opt ? opt->opt_flen : 0) -
1228 rt->rt6i_nfheader_len;
1229 length += exthdrlen;
1230 transhdrlen += exthdrlen;
1232 rt = (struct rt6_info *)cork->dst;
1233 fl6 = &inet->cork.fl.u.ip6;
1237 mtu = cork->fragsize;
1240 hh_len = LL_RESERVED_SPACE(rt->dst.dev);
1242 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
1243 (opt ? opt->opt_nflen : 0);
1244 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
1246 if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
1247 if (cork->length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
1248 ipv6_local_error(sk, EMSGSIZE, fl6, mtu-exthdrlen);
1253 /* For UDP, check if TX timestamp is enabled */
1254 if (sk->sk_type == SOCK_DGRAM) {
1255 err = sock_tx_timestamp(sk, &tx_flags);
1261 * Let's try using as much space as possible.
1262 * Use MTU if total length of the message fits into the MTU.
1263 * Otherwise, we need to reserve fragment header and
1264 * fragment alignment (= 8-15 octects, in total).
1266 * Note that we may need to "move" the data from the tail of
1267 * of the buffer to the new fragment when we split
1270 * FIXME: It may be fragmented into multiple chunks
1271 * at once if non-fragmentable extension headers
1276 cork->length += length;
1278 int proto = sk->sk_protocol;
1279 if (dontfrag && (proto == IPPROTO_UDP || proto == IPPROTO_RAW)){
1280 ipv6_local_rxpmtu(sk, fl6, mtu-exthdrlen);
1284 if (proto == IPPROTO_UDP &&
1285 (rt->dst.dev->features & NETIF_F_UFO)) {
1287 err = ip6_ufo_append_data(sk, getfrag, from, length,
1288 hh_len, fragheaderlen,
1289 transhdrlen, mtu, flags);
1296 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1299 while (length > 0) {
1300 /* Check if the remaining data fits into current packet. */
1301 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1303 copy = maxfraglen - skb->len;
1307 unsigned int datalen;
1308 unsigned int fraglen;
1309 unsigned int fraggap;
1310 unsigned int alloclen;
1311 struct sk_buff *skb_prev;
1315 /* There's no room in the current skb */
1317 fraggap = skb_prev->len - maxfraglen;
1322 * If remaining data exceeds the mtu,
1323 * we know we need more fragment(s).
1325 datalen = length + fraggap;
1326 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1327 datalen = maxfraglen - fragheaderlen;
1329 fraglen = datalen + fragheaderlen;
1330 if ((flags & MSG_MORE) &&
1331 !(rt->dst.dev->features&NETIF_F_SG))
1334 alloclen = datalen + fragheaderlen;
1337 * The last fragment gets additional space at tail.
1338 * Note: we overallocate on fragments with MSG_MODE
1339 * because we have no idea if we're the last one.
1341 if (datalen == length + fraggap)
1342 alloclen += rt->dst.trailer_len;
1345 * We just reserve space for fragment header.
1346 * Note: this may be overallocation if the message
1347 * (without MSG_MORE) fits into the MTU.
1349 alloclen += sizeof(struct frag_hdr);
1352 skb = sock_alloc_send_skb(sk,
1354 (flags & MSG_DONTWAIT), &err);
1357 if (atomic_read(&sk->sk_wmem_alloc) <=
1359 skb = sock_wmalloc(sk,
1360 alloclen + hh_len, 1,
1362 if (unlikely(skb == NULL))
1365 /* Only the initial fragment
1374 * Fill in the control structures
1376 skb->ip_summed = csummode;
1378 /* reserve for fragmentation */
1379 skb_reserve(skb, hh_len+sizeof(struct frag_hdr));
1381 if (sk->sk_type == SOCK_DGRAM)
1382 skb_shinfo(skb)->tx_flags = tx_flags;
1385 * Find where to start putting bytes
1387 data = skb_put(skb, fraglen);
1388 skb_set_network_header(skb, exthdrlen);
1389 data += fragheaderlen;
1390 skb->transport_header = (skb->network_header +
1393 skb->csum = skb_copy_and_csum_bits(
1394 skb_prev, maxfraglen,
1395 data + transhdrlen, fraggap, 0);
1396 skb_prev->csum = csum_sub(skb_prev->csum,
1399 pskb_trim_unique(skb_prev, maxfraglen);
1401 copy = datalen - transhdrlen - fraggap;
1406 } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1413 length -= datalen - fraggap;
1416 csummode = CHECKSUM_NONE;
1419 * Put the packet on the pending queue
1421 __skb_queue_tail(&sk->sk_write_queue, skb);
1428 if (!(rt->dst.dev->features&NETIF_F_SG)) {
1432 if (getfrag(from, skb_put(skb, copy),
1433 offset, copy, off, skb) < 0) {
1434 __skb_trim(skb, off);
1439 int i = skb_shinfo(skb)->nr_frags;
1440 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
1441 struct page *page = sk->sk_sndmsg_page;
1442 int off = sk->sk_sndmsg_off;
1445 if (page && (left = PAGE_SIZE - off) > 0) {
1448 if (page != frag->page) {
1449 if (i == MAX_SKB_FRAGS) {
1454 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
1455 frag = &skb_shinfo(skb)->frags[i];
1457 } else if(i < MAX_SKB_FRAGS) {
1458 if (copy > PAGE_SIZE)
1460 page = alloc_pages(sk->sk_allocation, 0);
1465 sk->sk_sndmsg_page = page;
1466 sk->sk_sndmsg_off = 0;
1468 skb_fill_page_desc(skb, i, page, 0, 0);
1469 frag = &skb_shinfo(skb)->frags[i];
1474 if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
1478 sk->sk_sndmsg_off += copy;
1481 skb->data_len += copy;
1482 skb->truesize += copy;
1483 atomic_add(copy, &sk->sk_wmem_alloc);
1490 cork->length -= length;
1491 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1495 static void ip6_cork_release(struct inet_sock *inet, struct ipv6_pinfo *np)
1498 kfree(np->cork.opt->dst0opt);
1499 kfree(np->cork.opt->dst1opt);
1500 kfree(np->cork.opt->hopopt);
1501 kfree(np->cork.opt->srcrt);
1502 kfree(np->cork.opt);
1503 np->cork.opt = NULL;
1506 if (inet->cork.base.dst) {
1507 dst_release(inet->cork.base.dst);
1508 inet->cork.base.dst = NULL;
1509 inet->cork.base.flags &= ~IPCORK_ALLFRAG;
1511 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1514 int ip6_push_pending_frames(struct sock *sk)
1516 struct sk_buff *skb, *tmp_skb;
1517 struct sk_buff **tail_skb;
1518 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1519 struct inet_sock *inet = inet_sk(sk);
1520 struct ipv6_pinfo *np = inet6_sk(sk);
1521 struct net *net = sock_net(sk);
1522 struct ipv6hdr *hdr;
1523 struct ipv6_txoptions *opt = np->cork.opt;
1524 struct rt6_info *rt = (struct rt6_info *)inet->cork.base.dst;
1525 struct flowi6 *fl6 = &inet->cork.fl.u.ip6;
1526 unsigned char proto = fl6->flowi6_proto;
1529 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1531 tail_skb = &(skb_shinfo(skb)->frag_list);
1533 /* move skb->data to ip header from ext header */
1534 if (skb->data < skb_network_header(skb))
1535 __skb_pull(skb, skb_network_offset(skb));
1536 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1537 __skb_pull(tmp_skb, skb_network_header_len(skb));
1538 *tail_skb = tmp_skb;
1539 tail_skb = &(tmp_skb->next);
1540 skb->len += tmp_skb->len;
1541 skb->data_len += tmp_skb->len;
1542 skb->truesize += tmp_skb->truesize;
1543 tmp_skb->destructor = NULL;
1547 /* Allow local fragmentation. */
1548 if (np->pmtudisc < IPV6_PMTUDISC_DO)
1551 ipv6_addr_copy(final_dst, &fl6->daddr);
1552 __skb_pull(skb, skb_network_header_len(skb));
1553 if (opt && opt->opt_flen)
1554 ipv6_push_frag_opts(skb, opt, &proto);
1555 if (opt && opt->opt_nflen)
1556 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1558 skb_push(skb, sizeof(struct ipv6hdr));
1559 skb_reset_network_header(skb);
1560 hdr = ipv6_hdr(skb);
1562 *(__be32*)hdr = fl6->flowlabel |
1563 htonl(0x60000000 | ((int)np->cork.tclass << 20));
1565 hdr->hop_limit = np->cork.hop_limit;
1566 hdr->nexthdr = proto;
1567 ipv6_addr_copy(&hdr->saddr, &fl6->saddr);
1568 ipv6_addr_copy(&hdr->daddr, final_dst);
1570 skb->priority = sk->sk_priority;
1571 skb->mark = sk->sk_mark;
1573 skb_dst_set(skb, dst_clone(&rt->dst));
1574 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);
1575 if (proto == IPPROTO_ICMPV6) {
1576 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
1578 ICMP6MSGOUT_INC_STATS_BH(net, idev, icmp6_hdr(skb)->icmp6_type);
1579 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTMSGS);
1582 err = ip6_local_out(skb);
1585 err = net_xmit_errno(err);
1591 ip6_cork_release(inet, np);
1594 IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1598 void ip6_flush_pending_frames(struct sock *sk)
1600 struct sk_buff *skb;
1602 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
1604 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)),
1605 IPSTATS_MIB_OUTDISCARDS);
1609 ip6_cork_release(inet_sk(sk), inet6_sk(sk));