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/bpf-cgroup.h>
43 #include <linux/netfilter.h>
44 #include <linux/netfilter_ipv6.h>
50 #include <net/ndisc.h>
51 #include <net/protocol.h>
52 #include <net/ip6_route.h>
53 #include <net/addrconf.h>
54 #include <net/rawv6.h>
57 #include <net/checksum.h>
58 #include <linux/mroute6.h>
59 #include <net/l3mdev.h>
60 #include <net/lwtunnel.h>
62 static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
64 struct dst_entry *dst = skb_dst(skb);
65 struct net_device *dev = dst->dev;
66 struct neighbour *neigh;
67 struct in6_addr *nexthop;
70 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
71 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
73 if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) &&
74 ((mroute6_socket(net, skb) &&
75 !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
76 ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
77 &ipv6_hdr(skb)->saddr))) {
78 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
80 /* Do not check for IFF_ALLMULTI; multicast routing
81 is not supported in any case.
84 NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING,
85 net, sk, newskb, NULL, newskb->dev,
88 if (ipv6_hdr(skb)->hop_limit == 0) {
89 IP6_INC_STATS(net, idev,
90 IPSTATS_MIB_OUTDISCARDS);
96 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUTMCAST, skb->len);
98 if (IPV6_ADDR_MC_SCOPE(&ipv6_hdr(skb)->daddr) <=
99 IPV6_ADDR_SCOPE_NODELOCAL &&
100 !(dev->flags & IFF_LOOPBACK)) {
106 if (lwtunnel_xmit_redirect(dst->lwtstate)) {
107 int res = lwtunnel_xmit(skb);
109 if (res < 0 || res == LWTUNNEL_XMIT_DONE)
114 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
115 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
116 if (unlikely(!neigh))
117 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
118 if (!IS_ERR(neigh)) {
119 sock_confirm_neigh(skb, neigh);
120 ret = neigh_output(neigh, skb);
121 rcu_read_unlock_bh();
124 rcu_read_unlock_bh();
126 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
132 ip6_finish_output_gso_slowpath_drop(struct net *net, struct sock *sk,
133 struct sk_buff *skb, unsigned int mtu)
135 struct sk_buff *segs, *nskb;
136 netdev_features_t features;
139 /* Please see corresponding comment in ip_finish_output_gso
140 * describing the cases where GSO segment length exceeds the
143 features = netif_skb_features(skb);
144 segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
145 if (IS_ERR_OR_NULL(segs)) {
152 skb_list_walk_safe(segs, segs, nskb) {
155 skb_mark_not_on_list(segs);
156 err = ip6_fragment(net, sk, segs, ip6_finish_output2);
164 static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
169 ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb);
175 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM)
176 /* Policy lookup after SNAT yielded a new policy */
177 if (skb_dst(skb)->xfrm) {
178 IP6CB(skb)->flags |= IP6SKB_REROUTED;
179 return dst_output(net, sk, skb);
183 mtu = ip6_skb_dst_mtu(skb);
184 if (skb_is_gso(skb) && !skb_gso_validate_mtu(skb, mtu))
185 return ip6_finish_output_gso_slowpath_drop(net, sk, skb, mtu);
187 if ((skb->len > mtu && !skb_is_gso(skb)) ||
188 dst_allfrag(skb_dst(skb)) ||
189 (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size))
190 return ip6_fragment(net, sk, skb, ip6_finish_output2);
192 return ip6_finish_output2(net, sk, skb);
195 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
197 struct net_device *dev = skb_dst(skb)->dev;
198 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
200 skb->protocol = htons(ETH_P_IPV6);
203 if (unlikely(idev->cnf.disable_ipv6)) {
204 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
209 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
210 net, sk, skb, NULL, dev,
212 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
215 bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np)
217 if (!np->autoflowlabel_set)
218 return ip6_default_np_autolabel(net);
220 return np->autoflowlabel;
224 * xmit an sk_buff (used by TCP, SCTP and DCCP)
225 * Note : socket lock is not held for SYNACK packets, but might be modified
226 * by calls to skb_set_owner_w() and ipv6_local_error(),
227 * which are using proper atomic operations or spinlocks.
229 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
230 __u32 mark, struct ipv6_txoptions *opt, int tclass)
232 struct net *net = sock_net(sk);
233 const struct ipv6_pinfo *np = inet6_sk(sk);
234 struct in6_addr *first_hop = &fl6->daddr;
235 struct dst_entry *dst = skb_dst(skb);
236 unsigned int head_room;
238 u8 proto = fl6->flowi6_proto;
239 int seg_len = skb->len;
243 head_room = sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
245 head_room += opt->opt_nflen + opt->opt_flen;
247 if (unlikely(skb_headroom(skb) < head_room)) {
248 struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
250 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
251 IPSTATS_MIB_OUTDISCARDS);
256 skb_set_owner_w(skb2, skb->sk);
262 seg_len += opt->opt_nflen + opt->opt_flen;
265 ipv6_push_frag_opts(skb, opt, &proto);
268 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop,
272 skb_push(skb, sizeof(struct ipv6hdr));
273 skb_reset_network_header(skb);
277 * Fill in the IPv6 header
280 hlimit = np->hop_limit;
282 hlimit = ip6_dst_hoplimit(dst);
284 ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel,
285 ip6_autoflowlabel(net, np), fl6));
287 hdr->payload_len = htons(seg_len);
288 hdr->nexthdr = proto;
289 hdr->hop_limit = hlimit;
291 hdr->saddr = fl6->saddr;
292 hdr->daddr = *first_hop;
294 skb->protocol = htons(ETH_P_IPV6);
295 skb->priority = sk->sk_priority;
299 if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) {
300 IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
301 IPSTATS_MIB_OUT, skb->len);
303 /* if egress device is enslaved to an L3 master device pass the
304 * skb to its handler for processing
306 skb = l3mdev_ip6_out((struct sock *)sk, skb);
310 /* hooks should never assume socket lock is held.
311 * we promote our socket to non const
313 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
314 net, (struct sock *)sk, skb, NULL, dst->dev,
319 /* ipv6_local_error() does not require socket lock,
320 * we promote our socket to non const
322 ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu);
324 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS);
328 EXPORT_SYMBOL(ip6_xmit);
330 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
332 struct ip6_ra_chain *ra;
333 struct sock *last = NULL;
335 read_lock(&ip6_ra_lock);
336 for (ra = ip6_ra_chain; ra; ra = ra->next) {
337 struct sock *sk = ra->sk;
338 if (sk && ra->sel == sel &&
339 (!sk->sk_bound_dev_if ||
340 sk->sk_bound_dev_if == skb->dev->ifindex)) {
342 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
344 rawv6_rcv(last, skb2);
351 rawv6_rcv(last, skb);
352 read_unlock(&ip6_ra_lock);
355 read_unlock(&ip6_ra_lock);
359 static int ip6_forward_proxy_check(struct sk_buff *skb)
361 struct ipv6hdr *hdr = ipv6_hdr(skb);
362 u8 nexthdr = hdr->nexthdr;
366 if (ipv6_ext_hdr(nexthdr)) {
367 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off);
371 offset = sizeof(struct ipv6hdr);
373 if (nexthdr == IPPROTO_ICMPV6) {
374 struct icmp6hdr *icmp6;
376 if (!pskb_may_pull(skb, (skb_network_header(skb) +
377 offset + 1 - skb->data)))
380 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
382 switch (icmp6->icmp6_type) {
383 case NDISC_ROUTER_SOLICITATION:
384 case NDISC_ROUTER_ADVERTISEMENT:
385 case NDISC_NEIGHBOUR_SOLICITATION:
386 case NDISC_NEIGHBOUR_ADVERTISEMENT:
388 /* For reaction involving unicast neighbor discovery
389 * message destined to the proxied address, pass it to
399 * The proxying router can't forward traffic sent to a link-local
400 * address, so signal the sender and discard the packet. This
401 * behavior is clarified by the MIPv6 specification.
403 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
404 dst_link_failure(skb);
411 static inline int ip6_forward_finish(struct net *net, struct sock *sk,
414 struct dst_entry *dst = skb_dst(skb);
416 __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
417 __IP6_ADD_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len);
419 return dst_output(net, sk, skb);
422 static unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
425 struct inet6_dev *idev;
427 if (dst_metric_locked(dst, RTAX_MTU)) {
428 mtu = dst_metric_raw(dst, RTAX_MTU);
435 idev = __in6_dev_get(dst->dev);
437 mtu = idev->cnf.mtu6;
443 static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
448 /* ipv6 conntrack defrag sets max_frag_size + ignore_df */
449 if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)
455 if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
461 int ip6_forward(struct sk_buff *skb)
463 struct dst_entry *dst = skb_dst(skb);
464 struct ipv6hdr *hdr = ipv6_hdr(skb);
465 struct inet6_skb_parm *opt = IP6CB(skb);
466 struct net *net = dev_net(dst->dev);
469 if (net->ipv6.devconf_all->forwarding == 0)
472 if (skb->pkt_type != PACKET_HOST)
475 if (unlikely(skb->sk))
478 if (skb_warn_if_lro(skb))
481 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
482 __IP6_INC_STATS(net, ip6_dst_idev(dst),
483 IPSTATS_MIB_INDISCARDS);
487 skb_forward_csum(skb);
490 * We DO NOT make any processing on
491 * RA packets, pushing them to user level AS IS
492 * without ane WARRANTY that application will be able
493 * to interpret them. The reason is that we
494 * cannot make anything clever here.
496 * We are not end-node, so that if packet contains
497 * AH/ESP, we cannot make anything.
498 * Defragmentation also would be mistake, RA packets
499 * cannot be fragmented, because there is no warranty
500 * that different fragments will go along one path. --ANK
502 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
503 if (ip6_call_ra_chain(skb, ntohs(opt->ra)))
508 * check and decrement ttl
510 if (hdr->hop_limit <= 1) {
511 /* Force OUTPUT device used as source address */
513 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0);
514 __IP6_INC_STATS(net, ip6_dst_idev(dst),
515 IPSTATS_MIB_INHDRERRORS);
521 /* XXX: idev->cnf.proxy_ndp? */
522 if (net->ipv6.devconf_all->proxy_ndp &&
523 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) {
524 int proxied = ip6_forward_proxy_check(skb);
526 return ip6_input(skb);
527 else if (proxied < 0) {
528 __IP6_INC_STATS(net, ip6_dst_idev(dst),
529 IPSTATS_MIB_INDISCARDS);
534 if (!xfrm6_route_forward(skb)) {
535 __IP6_INC_STATS(net, ip6_dst_idev(dst),
536 IPSTATS_MIB_INDISCARDS);
541 /* IPv6 specs say nothing about it, but it is clear that we cannot
542 send redirects to source routed frames.
543 We don't send redirects to frames decapsulated from IPsec.
545 if (IP6CB(skb)->iif == dst->dev->ifindex &&
546 opt->srcrt == 0 && !skb_sec_path(skb)) {
547 struct in6_addr *target = NULL;
548 struct inet_peer *peer;
552 * incoming and outgoing devices are the same
556 rt = (struct rt6_info *) dst;
557 if (rt->rt6i_flags & RTF_GATEWAY)
558 target = &rt->rt6i_gateway;
560 target = &hdr->daddr;
562 peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1);
564 /* Limit redirects both by destination (here)
565 and by source (inside ndisc_send_redirect)
567 if (inet_peer_xrlim_allow(peer, 1*HZ))
568 ndisc_send_redirect(skb, target);
572 int addrtype = ipv6_addr_type(&hdr->saddr);
574 /* This check is security critical. */
575 if (addrtype == IPV6_ADDR_ANY ||
576 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK))
578 if (addrtype & IPV6_ADDR_LINKLOCAL) {
579 icmpv6_send(skb, ICMPV6_DEST_UNREACH,
580 ICMPV6_NOT_NEIGHBOUR, 0);
585 mtu = ip6_dst_mtu_forward(dst);
586 if (mtu < IPV6_MIN_MTU)
589 if (ip6_pkt_too_big(skb, mtu)) {
590 /* Again, force OUTPUT device used as source address */
592 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
593 __IP6_INC_STATS(net, ip6_dst_idev(dst),
594 IPSTATS_MIB_INTOOBIGERRORS);
595 __IP6_INC_STATS(net, ip6_dst_idev(dst),
596 IPSTATS_MIB_FRAGFAILS);
601 if (skb_cow(skb, dst->dev->hard_header_len)) {
602 __IP6_INC_STATS(net, ip6_dst_idev(dst),
603 IPSTATS_MIB_OUTDISCARDS);
609 /* Mangling hops number delayed to point after skb COW */
613 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD,
614 net, NULL, skb, skb->dev, dst->dev,
618 __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
624 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
626 to->pkt_type = from->pkt_type;
627 to->priority = from->priority;
628 to->protocol = from->protocol;
630 skb_dst_set(to, dst_clone(skb_dst(from)));
632 to->mark = from->mark;
634 skb_copy_hash(to, from);
636 #ifdef CONFIG_NET_SCHED
637 to->tc_index = from->tc_index;
640 skb_copy_secmark(to, from);
643 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
644 int (*output)(struct net *, struct sock *, struct sk_buff *))
646 struct sk_buff *frag;
647 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
648 struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
649 inet6_sk(skb->sk) : NULL;
650 struct ipv6hdr *tmp_hdr;
652 unsigned int mtu, hlen, left, len, nexthdr_offset;
655 int ptr, offset = 0, err = 0;
656 u8 *prevhdr, nexthdr = 0;
658 err = ip6_find_1stfragopt(skb, &prevhdr);
663 nexthdr_offset = prevhdr - skb_network_header(skb);
665 mtu = ip6_skb_dst_mtu(skb);
667 /* We must not fragment if the socket is set to force MTU discovery
668 * or if the skb it not generated by a local socket.
670 if (unlikely(!skb->ignore_df && skb->len > mtu))
673 if (IP6CB(skb)->frag_max_size) {
674 if (IP6CB(skb)->frag_max_size > mtu)
677 /* don't send fragments larger than what we received */
678 mtu = IP6CB(skb)->frag_max_size;
679 if (mtu < IPV6_MIN_MTU)
683 if (np && np->frag_size < mtu) {
687 if (mtu < hlen + sizeof(struct frag_hdr) + 8)
689 mtu -= hlen + sizeof(struct frag_hdr);
691 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
692 &ipv6_hdr(skb)->saddr);
694 if (skb->ip_summed == CHECKSUM_PARTIAL &&
695 (err = skb_checksum_help(skb)))
698 prevhdr = skb_network_header(skb) + nexthdr_offset;
699 hroom = LL_RESERVED_SPACE(rt->dst.dev);
700 if (skb_has_frag_list(skb)) {
701 unsigned int first_len = skb_pagelen(skb);
702 struct sk_buff *frag2;
704 if (first_len - hlen > mtu ||
705 ((first_len - hlen) & 7) ||
707 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr)))
710 skb_walk_frags(skb, frag) {
711 /* Correct geometry. */
712 if (frag->len > mtu ||
713 ((frag->len & 7) && frag->next) ||
714 skb_headroom(frag) < (hlen + hroom + sizeof(struct frag_hdr)))
715 goto slow_path_clean;
717 /* Partially cloned skb? */
718 if (skb_shared(frag))
719 goto slow_path_clean;
724 frag->destructor = sock_wfree;
726 skb->truesize -= frag->truesize;
733 *prevhdr = NEXTHDR_FRAGMENT;
734 tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
739 frag = skb_shinfo(skb)->frag_list;
740 skb_frag_list_init(skb);
742 __skb_pull(skb, hlen);
743 fh = __skb_push(skb, sizeof(struct frag_hdr));
744 __skb_push(skb, hlen);
745 skb_reset_network_header(skb);
746 memcpy(skb_network_header(skb), tmp_hdr, hlen);
748 fh->nexthdr = nexthdr;
750 fh->frag_off = htons(IP6_MF);
751 fh->identification = frag_id;
753 first_len = skb_pagelen(skb);
754 skb->data_len = first_len - skb_headlen(skb);
755 skb->len = first_len;
756 ipv6_hdr(skb)->payload_len = htons(first_len -
757 sizeof(struct ipv6hdr));
760 /* Prepare header of the next frame,
761 * before previous one went down. */
763 frag->ip_summed = CHECKSUM_NONE;
764 skb_reset_transport_header(frag);
765 fh = __skb_push(frag, sizeof(struct frag_hdr));
766 __skb_push(frag, hlen);
767 skb_reset_network_header(frag);
768 memcpy(skb_network_header(frag), tmp_hdr,
770 offset += skb->len - hlen - sizeof(struct frag_hdr);
771 fh->nexthdr = nexthdr;
773 fh->frag_off = htons(offset);
775 fh->frag_off |= htons(IP6_MF);
776 fh->identification = frag_id;
777 ipv6_hdr(frag)->payload_len =
779 sizeof(struct ipv6hdr));
780 ip6_copy_metadata(frag, skb);
783 err = output(net, sk, skb);
785 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
786 IPSTATS_MIB_FRAGCREATES);
799 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
800 IPSTATS_MIB_FRAGOKS);
804 kfree_skb_list(frag);
806 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
807 IPSTATS_MIB_FRAGFAILS);
811 skb_walk_frags(skb, frag2) {
815 frag2->destructor = NULL;
816 skb->truesize += frag2->truesize;
821 left = skb->len - hlen; /* Space per frame */
822 ptr = hlen; /* Where to start from */
825 * Fragment the datagram.
828 troom = rt->dst.dev->needed_tailroom;
831 * Keep copying data until we run out.
834 u8 *fragnexthdr_offset;
837 /* IF: it doesn't fit, use 'mtu' - the data space left */
840 /* IF: we are not sending up to and including the packet end
841 then align the next start on an eight byte boundary */
846 /* Allocate buffer */
847 frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) +
848 hroom + troom, GFP_ATOMIC);
855 * Set up data on packet
858 ip6_copy_metadata(frag, skb);
859 skb_reserve(frag, hroom);
860 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
861 skb_reset_network_header(frag);
862 fh = (struct frag_hdr *)(skb_network_header(frag) + hlen);
863 frag->transport_header = (frag->network_header + hlen +
864 sizeof(struct frag_hdr));
867 * Charge the memory for the fragment to any owner
871 skb_set_owner_w(frag, skb->sk);
874 * Copy the packet header into the new buffer.
876 skb_copy_from_linear_data(skb, skb_network_header(frag), hlen);
878 fragnexthdr_offset = skb_network_header(frag);
879 fragnexthdr_offset += prevhdr - skb_network_header(skb);
880 *fragnexthdr_offset = NEXTHDR_FRAGMENT;
883 * Build fragment header.
885 fh->nexthdr = nexthdr;
887 fh->identification = frag_id;
890 * Copy a block of the IP datagram.
892 BUG_ON(skb_copy_bits(skb, ptr, skb_transport_header(frag),
896 fh->frag_off = htons(offset);
898 fh->frag_off |= htons(IP6_MF);
899 ipv6_hdr(frag)->payload_len = htons(frag->len -
900 sizeof(struct ipv6hdr));
906 * Put this fragment into the sending queue.
908 err = output(net, sk, frag);
912 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
913 IPSTATS_MIB_FRAGCREATES);
915 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
916 IPSTATS_MIB_FRAGOKS);
921 if (skb->sk && dst_allfrag(skb_dst(skb)))
922 sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK);
924 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
928 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
929 IPSTATS_MIB_FRAGFAILS);
934 static inline int ip6_rt_check(const struct rt6key *rt_key,
935 const struct in6_addr *fl_addr,
936 const struct in6_addr *addr_cache)
938 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
939 (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache));
942 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
943 struct dst_entry *dst,
944 const struct flowi6 *fl6)
946 struct ipv6_pinfo *np = inet6_sk(sk);
952 if (dst->ops->family != AF_INET6) {
957 rt = (struct rt6_info *)dst;
958 /* Yes, checking route validity in not connected
959 * case is not very simple. Take into account,
960 * that we do not support routing by source, TOS,
961 * and MSG_DONTROUTE --ANK (980726)
963 * 1. ip6_rt_check(): If route was host route,
964 * check that cached destination is current.
965 * If it is network route, we still may
966 * check its validity using saved pointer
967 * to the last used address: daddr_cache.
968 * We do not want to save whole address now,
969 * (because main consumer of this service
970 * is tcp, which has not this problem),
971 * so that the last trick works only on connected
973 * 2. oif also should be the same.
975 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) ||
976 #ifdef CONFIG_IPV6_SUBTREES
977 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) ||
979 (!(fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) &&
980 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex))) {
989 static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk,
990 struct dst_entry **dst, struct flowi6 *fl6)
992 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
999 /* The correct way to handle this would be to do
1000 * ip6_route_get_saddr, and then ip6_route_output; however,
1001 * the route-specific preferred source forces the
1002 * ip6_route_output call _before_ ip6_route_get_saddr.
1004 * In source specific routing (no src=any default route),
1005 * ip6_route_output will fail given src=any saddr, though, so
1006 * that's why we try it again later.
1008 if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) {
1009 struct rt6_info *rt;
1010 bool had_dst = *dst != NULL;
1013 *dst = ip6_route_output(net, sk, fl6);
1014 rt = (*dst)->error ? NULL : (struct rt6_info *)*dst;
1015 err = ip6_route_get_saddr(net, rt, &fl6->daddr,
1016 sk ? inet6_sk(sk)->srcprefs : 0,
1019 goto out_err_release;
1021 /* If we had an erroneous initial result, pretend it
1022 * never existed and let the SA-enabled version take
1025 if (!had_dst && (*dst)->error) {
1030 if (fl6->flowi6_oif)
1031 flags |= RT6_LOOKUP_F_IFACE;
1035 *dst = ip6_route_output_flags(net, sk, fl6, flags);
1037 err = (*dst)->error;
1039 goto out_err_release;
1041 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
1043 * Here if the dst entry we've looked up
1044 * has a neighbour entry that is in the INCOMPLETE
1045 * state and the src address from the flow is
1046 * marked as OPTIMISTIC, we release the found
1047 * dst entry and replace it instead with the
1048 * dst entry of the nexthop router
1050 rt = (struct rt6_info *) *dst;
1052 n = __ipv6_neigh_lookup_noref(rt->dst.dev,
1053 rt6_nexthop(rt, &fl6->daddr));
1054 err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0;
1055 rcu_read_unlock_bh();
1058 struct inet6_ifaddr *ifp;
1059 struct flowi6 fl_gw6;
1062 ifp = ipv6_get_ifaddr(net, &fl6->saddr,
1065 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
1071 * We need to get the dst entry for the
1072 * default router instead
1075 memcpy(&fl_gw6, fl6, sizeof(struct flowi6));
1076 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr));
1077 *dst = ip6_route_output(net, sk, &fl_gw6);
1078 err = (*dst)->error;
1080 goto out_err_release;
1084 if (ipv6_addr_v4mapped(&fl6->saddr) &&
1085 !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) {
1086 err = -EAFNOSUPPORT;
1087 goto out_err_release;
1096 if (err == -ENETUNREACH)
1097 IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES);
1102 * ip6_dst_lookup - perform route lookup on flow
1103 * @sk: socket which provides route info
1104 * @dst: pointer to dst_entry * for result
1105 * @fl6: flow to lookup
1107 * This function performs a route lookup on the given flow.
1109 * It returns zero on success, or a standard errno code on error.
1111 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
1115 return ip6_dst_lookup_tail(net, sk, dst, fl6);
1117 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
1120 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec
1121 * @sk: socket which provides route info
1122 * @fl6: flow to lookup
1123 * @final_dst: final destination address for ipsec lookup
1125 * This function performs a route lookup on the given flow.
1127 * It returns a valid dst pointer on success, or a pointer encoded
1130 struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, struct flowi6 *fl6,
1131 const struct in6_addr *final_dst)
1133 struct dst_entry *dst = NULL;
1136 err = ip6_dst_lookup_tail(net, sk, &dst, fl6);
1138 return ERR_PTR(err);
1140 fl6->daddr = *final_dst;
1142 return xfrm_lookup_route(net, dst, flowi6_to_flowi(fl6), sk, 0);
1144 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
1147 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow
1148 * @sk: socket which provides the dst cache and route info
1149 * @fl6: flow to lookup
1150 * @final_dst: final destination address for ipsec lookup
1152 * This function performs a route lookup on the given flow with the
1153 * possibility of using the cached route in the socket if it is valid.
1154 * It will take the socket dst lock when operating on the dst cache.
1155 * As a result, this function can only be used in process context.
1157 * It returns a valid dst pointer on success, or a pointer encoded
1160 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1161 const struct in6_addr *final_dst)
1163 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
1165 dst = ip6_sk_dst_check(sk, dst, fl6);
1167 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_dst);
1171 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow);
1173 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src,
1176 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1179 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src,
1182 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1185 static void ip6_append_data_mtu(unsigned int *mtu,
1187 unsigned int fragheaderlen,
1188 struct sk_buff *skb,
1189 struct rt6_info *rt,
1190 unsigned int orig_mtu)
1192 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
1194 /* first fragment, reserve header_len */
1195 *mtu = orig_mtu - rt->dst.header_len;
1199 * this fragment is not first, the headers
1200 * space is regarded as data space.
1204 *maxfraglen = ((*mtu - fragheaderlen) & ~7)
1205 + fragheaderlen - sizeof(struct frag_hdr);
1209 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
1210 struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6,
1211 struct rt6_info *rt, struct flowi6 *fl6)
1213 struct ipv6_pinfo *np = inet6_sk(sk);
1215 struct ipv6_txoptions *opt = ipc6->opt;
1221 if (WARN_ON(v6_cork->opt))
1224 v6_cork->opt = kzalloc(sizeof(*opt), sk->sk_allocation);
1225 if (unlikely(!v6_cork->opt))
1228 v6_cork->opt->tot_len = sizeof(*opt);
1229 v6_cork->opt->opt_flen = opt->opt_flen;
1230 v6_cork->opt->opt_nflen = opt->opt_nflen;
1232 v6_cork->opt->dst0opt = ip6_opt_dup(opt->dst0opt,
1234 if (opt->dst0opt && !v6_cork->opt->dst0opt)
1237 v6_cork->opt->dst1opt = ip6_opt_dup(opt->dst1opt,
1239 if (opt->dst1opt && !v6_cork->opt->dst1opt)
1242 v6_cork->opt->hopopt = ip6_opt_dup(opt->hopopt,
1244 if (opt->hopopt && !v6_cork->opt->hopopt)
1247 v6_cork->opt->srcrt = ip6_rthdr_dup(opt->srcrt,
1249 if (opt->srcrt && !v6_cork->opt->srcrt)
1252 /* need source address above miyazawa*/
1255 cork->base.dst = &rt->dst;
1256 cork->fl.u.ip6 = *fl6;
1257 v6_cork->hop_limit = ipc6->hlimit;
1258 v6_cork->tclass = ipc6->tclass;
1259 if (rt->dst.flags & DST_XFRM_TUNNEL)
1260 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
1261 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst);
1263 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
1264 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(rt->dst.path);
1265 if (np->frag_size < mtu) {
1267 mtu = np->frag_size;
1269 cork->base.fragsize = mtu;
1270 if (dst_allfrag(rt->dst.path))
1271 cork->base.flags |= IPCORK_ALLFRAG;
1272 cork->base.length = 0;
1277 static int __ip6_append_data(struct sock *sk,
1279 struct sk_buff_head *queue,
1280 struct inet_cork *cork,
1281 struct inet6_cork *v6_cork,
1282 struct page_frag *pfrag,
1283 int getfrag(void *from, char *to, int offset,
1284 int len, int odd, struct sk_buff *skb),
1285 void *from, int length, int transhdrlen,
1286 unsigned int flags, struct ipcm6_cookie *ipc6,
1287 const struct sockcm_cookie *sockc)
1289 struct sk_buff *skb, *skb_prev = NULL;
1290 unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu;
1292 int dst_exthdrlen = 0;
1299 struct rt6_info *rt = (struct rt6_info *)cork->dst;
1300 struct ipv6_txoptions *opt = v6_cork->opt;
1301 int csummode = CHECKSUM_NONE;
1302 unsigned int maxnonfragsize, headersize;
1304 skb = skb_peek_tail(queue);
1306 exthdrlen = opt ? opt->opt_flen : 0;
1307 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len;
1310 mtu = cork->fragsize;
1313 hh_len = LL_RESERVED_SPACE(rt->dst.dev);
1315 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
1316 (opt ? opt->opt_nflen : 0);
1318 headersize = sizeof(struct ipv6hdr) +
1319 (opt ? opt->opt_flen + opt->opt_nflen : 0) +
1320 (dst_allfrag(&rt->dst) ?
1321 sizeof(struct frag_hdr) : 0) +
1322 rt->rt6i_nfheader_len;
1324 if (mtu <= fragheaderlen ||
1325 ((mtu - fragheaderlen) & ~7) + fragheaderlen <= sizeof(struct frag_hdr))
1328 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen -
1329 sizeof(struct frag_hdr);
1331 /* as per RFC 7112 section 5, the entire IPv6 Header Chain must fit
1332 * the first fragment
1334 if (headersize + transhdrlen > mtu)
1337 if (cork->length + length > mtu - headersize && ipc6->dontfrag &&
1338 (sk->sk_protocol == IPPROTO_UDP ||
1339 sk->sk_protocol == IPPROTO_RAW)) {
1340 ipv6_local_rxpmtu(sk, fl6, mtu - headersize +
1341 sizeof(struct ipv6hdr));
1345 if (ip6_sk_ignore_df(sk))
1346 maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN;
1348 maxnonfragsize = mtu;
1350 if (cork->length + length > maxnonfragsize - headersize) {
1352 pmtu = max_t(int, mtu - headersize + sizeof(struct ipv6hdr), 0);
1353 ipv6_local_error(sk, EMSGSIZE, fl6, pmtu);
1357 /* CHECKSUM_PARTIAL only with no extension headers and when
1358 * we are not going to fragment
1360 if (transhdrlen && sk->sk_protocol == IPPROTO_UDP &&
1361 headersize == sizeof(struct ipv6hdr) &&
1362 length <= mtu - headersize &&
1363 !(flags & MSG_MORE) &&
1364 rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM))
1365 csummode = CHECKSUM_PARTIAL;
1367 if (sk->sk_type == SOCK_DGRAM || sk->sk_type == SOCK_RAW) {
1368 sock_tx_timestamp(sk, sockc->tsflags, &tx_flags);
1369 if (tx_flags & SKBTX_ANY_SW_TSTAMP &&
1370 sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)
1371 tskey = sk->sk_tskey++;
1375 * Let's try using as much space as possible.
1376 * Use MTU if total length of the message fits into the MTU.
1377 * Otherwise, we need to reserve fragment header and
1378 * fragment alignment (= 8-15 octects, in total).
1380 * Note that we may need to "move" the data from the tail of
1381 * of the buffer to the new fragment when we split
1384 * FIXME: It may be fragmented into multiple chunks
1385 * at once if non-fragmentable extension headers
1390 cork->length += length;
1394 while (length > 0) {
1395 /* Check if the remaining data fits into current packet. */
1396 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1398 copy = maxfraglen - skb->len;
1402 unsigned int datalen;
1403 unsigned int fraglen;
1404 unsigned int fraggap;
1405 unsigned int alloclen;
1407 /* There's no room in the current skb */
1409 fraggap = skb->len - maxfraglen;
1412 /* update mtu and maxfraglen if necessary */
1413 if (!skb || !skb_prev)
1414 ip6_append_data_mtu(&mtu, &maxfraglen,
1415 fragheaderlen, skb, rt,
1421 * If remaining data exceeds the mtu,
1422 * we know we need more fragment(s).
1424 datalen = length + fraggap;
1426 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1427 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
1428 if ((flags & MSG_MORE) &&
1429 !(rt->dst.dev->features&NETIF_F_SG))
1432 alloclen = datalen + fragheaderlen;
1434 alloclen += dst_exthdrlen;
1436 if (datalen != length + fraggap) {
1438 * this is not the last fragment, the trailer
1439 * space is regarded as data space.
1441 datalen += rt->dst.trailer_len;
1444 alloclen += rt->dst.trailer_len;
1445 fraglen = datalen + fragheaderlen;
1448 * We just reserve space for fragment header.
1449 * Note: this may be overallocation if the message
1450 * (without MSG_MORE) fits into the MTU.
1452 alloclen += sizeof(struct frag_hdr);
1454 copy = datalen - transhdrlen - fraggap;
1460 skb = sock_alloc_send_skb(sk,
1462 (flags & MSG_DONTWAIT), &err);
1465 if (refcount_read(&sk->sk_wmem_alloc) <=
1467 skb = sock_wmalloc(sk,
1468 alloclen + hh_len, 1,
1476 * Fill in the control structures
1478 skb->protocol = htons(ETH_P_IPV6);
1479 skb->ip_summed = csummode;
1481 /* reserve for fragmentation and ipsec header */
1482 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) +
1485 /* Only the initial fragment is time stamped */
1486 skb_shinfo(skb)->tx_flags = tx_flags;
1488 skb_shinfo(skb)->tskey = tskey;
1492 * Find where to start putting bytes
1494 data = skb_put(skb, fraglen);
1495 skb_set_network_header(skb, exthdrlen);
1496 data += fragheaderlen;
1497 skb->transport_header = (skb->network_header +
1500 skb->csum = skb_copy_and_csum_bits(
1501 skb_prev, maxfraglen,
1502 data + transhdrlen, fraggap, 0);
1503 skb_prev->csum = csum_sub(skb_prev->csum,
1506 pskb_trim_unique(skb_prev, maxfraglen);
1509 getfrag(from, data + transhdrlen, offset,
1510 copy, fraggap, skb) < 0) {
1517 length -= datalen - fraggap;
1522 if ((flags & MSG_CONFIRM) && !skb_prev)
1523 skb_set_dst_pending_confirm(skb, 1);
1526 * Put the packet on the pending queue
1528 __skb_queue_tail(queue, skb);
1535 if (!(rt->dst.dev->features&NETIF_F_SG) &&
1536 skb_tailroom(skb) >= copy) {
1540 if (getfrag(from, skb_put(skb, copy),
1541 offset, copy, off, skb) < 0) {
1542 __skb_trim(skb, off);
1547 int i = skb_shinfo(skb)->nr_frags;
1550 if (!sk_page_frag_refill(sk, pfrag))
1553 if (!skb_can_coalesce(skb, i, pfrag->page,
1556 if (i == MAX_SKB_FRAGS)
1559 __skb_fill_page_desc(skb, i, pfrag->page,
1561 skb_shinfo(skb)->nr_frags = ++i;
1562 get_page(pfrag->page);
1564 copy = min_t(int, copy, pfrag->size - pfrag->offset);
1566 page_address(pfrag->page) + pfrag->offset,
1567 offset, copy, skb->len, skb) < 0)
1570 pfrag->offset += copy;
1571 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1573 skb->data_len += copy;
1574 skb->truesize += copy;
1575 refcount_add(copy, &sk->sk_wmem_alloc);
1586 cork->length -= length;
1587 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1591 int ip6_append_data(struct sock *sk,
1592 int getfrag(void *from, char *to, int offset, int len,
1593 int odd, struct sk_buff *skb),
1594 void *from, int length, int transhdrlen,
1595 struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1596 struct rt6_info *rt, unsigned int flags,
1597 const struct sockcm_cookie *sockc)
1599 struct inet_sock *inet = inet_sk(sk);
1600 struct ipv6_pinfo *np = inet6_sk(sk);
1604 if (flags&MSG_PROBE)
1606 if (skb_queue_empty(&sk->sk_write_queue)) {
1610 err = ip6_setup_cork(sk, &inet->cork, &np->cork,
1615 exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
1616 length += exthdrlen;
1617 transhdrlen += exthdrlen;
1619 fl6 = &inet->cork.fl.u.ip6;
1623 return __ip6_append_data(sk, fl6, &sk->sk_write_queue, &inet->cork.base,
1624 &np->cork, sk_page_frag(sk), getfrag,
1625 from, length, transhdrlen, flags, ipc6, sockc);
1627 EXPORT_SYMBOL_GPL(ip6_append_data);
1629 static void ip6_cork_release(struct inet_cork_full *cork,
1630 struct inet6_cork *v6_cork)
1633 kfree(v6_cork->opt->dst0opt);
1634 kfree(v6_cork->opt->dst1opt);
1635 kfree(v6_cork->opt->hopopt);
1636 kfree(v6_cork->opt->srcrt);
1637 kfree(v6_cork->opt);
1638 v6_cork->opt = NULL;
1641 if (cork->base.dst) {
1642 dst_release(cork->base.dst);
1643 cork->base.dst = NULL;
1644 cork->base.flags &= ~IPCORK_ALLFRAG;
1646 memset(&cork->fl, 0, sizeof(cork->fl));
1649 struct sk_buff *__ip6_make_skb(struct sock *sk,
1650 struct sk_buff_head *queue,
1651 struct inet_cork_full *cork,
1652 struct inet6_cork *v6_cork)
1654 struct sk_buff *skb, *tmp_skb;
1655 struct sk_buff **tail_skb;
1656 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1657 struct ipv6_pinfo *np = inet6_sk(sk);
1658 struct net *net = sock_net(sk);
1659 struct ipv6hdr *hdr;
1660 struct ipv6_txoptions *opt = v6_cork->opt;
1661 struct rt6_info *rt = (struct rt6_info *)cork->base.dst;
1662 struct flowi6 *fl6 = &cork->fl.u.ip6;
1663 unsigned char proto = fl6->flowi6_proto;
1665 skb = __skb_dequeue(queue);
1668 tail_skb = &(skb_shinfo(skb)->frag_list);
1670 /* move skb->data to ip header from ext header */
1671 if (skb->data < skb_network_header(skb))
1672 __skb_pull(skb, skb_network_offset(skb));
1673 while ((tmp_skb = __skb_dequeue(queue)) != NULL) {
1674 __skb_pull(tmp_skb, skb_network_header_len(skb));
1675 *tail_skb = tmp_skb;
1676 tail_skb = &(tmp_skb->next);
1677 skb->len += tmp_skb->len;
1678 skb->data_len += tmp_skb->len;
1679 skb->truesize += tmp_skb->truesize;
1680 tmp_skb->destructor = NULL;
1684 /* Allow local fragmentation. */
1685 skb->ignore_df = ip6_sk_ignore_df(sk);
1687 *final_dst = fl6->daddr;
1688 __skb_pull(skb, skb_network_header_len(skb));
1689 if (opt && opt->opt_flen)
1690 ipv6_push_frag_opts(skb, opt, &proto);
1691 if (opt && opt->opt_nflen)
1692 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst, &fl6->saddr);
1694 skb_push(skb, sizeof(struct ipv6hdr));
1695 skb_reset_network_header(skb);
1696 hdr = ipv6_hdr(skb);
1698 ip6_flow_hdr(hdr, v6_cork->tclass,
1699 ip6_make_flowlabel(net, skb, fl6->flowlabel,
1700 ip6_autoflowlabel(net, np), fl6));
1701 hdr->hop_limit = v6_cork->hop_limit;
1702 hdr->nexthdr = proto;
1703 hdr->saddr = fl6->saddr;
1704 hdr->daddr = *final_dst;
1706 skb->priority = sk->sk_priority;
1707 skb->mark = sk->sk_mark;
1709 skb_dst_set(skb, dst_clone(&rt->dst));
1710 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);
1711 if (proto == IPPROTO_ICMPV6) {
1712 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
1714 ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type);
1715 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1718 ip6_cork_release(cork, v6_cork);
1723 int ip6_send_skb(struct sk_buff *skb)
1725 struct net *net = sock_net(skb->sk);
1726 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
1729 err = ip6_local_out(net, skb->sk, skb);
1732 err = net_xmit_errno(err);
1734 IP6_INC_STATS(net, rt->rt6i_idev,
1735 IPSTATS_MIB_OUTDISCARDS);
1741 int ip6_push_pending_frames(struct sock *sk)
1743 struct sk_buff *skb;
1745 skb = ip6_finish_skb(sk);
1749 return ip6_send_skb(skb);
1751 EXPORT_SYMBOL_GPL(ip6_push_pending_frames);
1753 static void __ip6_flush_pending_frames(struct sock *sk,
1754 struct sk_buff_head *queue,
1755 struct inet_cork_full *cork,
1756 struct inet6_cork *v6_cork)
1758 struct sk_buff *skb;
1760 while ((skb = __skb_dequeue_tail(queue)) != NULL) {
1762 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)),
1763 IPSTATS_MIB_OUTDISCARDS);
1767 ip6_cork_release(cork, v6_cork);
1770 void ip6_flush_pending_frames(struct sock *sk)
1772 __ip6_flush_pending_frames(sk, &sk->sk_write_queue,
1773 &inet_sk(sk)->cork, &inet6_sk(sk)->cork);
1775 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames);
1777 struct sk_buff *ip6_make_skb(struct sock *sk,
1778 int getfrag(void *from, char *to, int offset,
1779 int len, int odd, struct sk_buff *skb),
1780 void *from, int length, int transhdrlen,
1781 struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1782 struct rt6_info *rt, unsigned int flags,
1783 const struct sockcm_cookie *sockc)
1785 struct inet_cork_full cork;
1786 struct inet6_cork v6_cork;
1787 struct sk_buff_head queue;
1788 int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
1791 if (flags & MSG_PROBE)
1794 __skb_queue_head_init(&queue);
1796 cork.base.flags = 0;
1798 cork.base.opt = NULL;
1799 cork.base.dst = NULL;
1801 err = ip6_setup_cork(sk, &cork, &v6_cork, ipc6, rt, fl6);
1803 ip6_cork_release(&cork, &v6_cork);
1804 return ERR_PTR(err);
1806 if (ipc6->dontfrag < 0)
1807 ipc6->dontfrag = inet6_sk(sk)->dontfrag;
1809 err = __ip6_append_data(sk, fl6, &queue, &cork.base, &v6_cork,
1810 ¤t->task_frag, getfrag, from,
1811 length + exthdrlen, transhdrlen + exthdrlen,
1812 flags, ipc6, sockc);
1814 __ip6_flush_pending_frames(sk, &queue, &cork, &v6_cork);
1815 return ERR_PTR(err);
1818 return __ip6_make_skb(sk, &queue, &cork, &v6_cork);