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 static 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
;
104 skb
->protocol
= htons(ETH_P_IPV6
);
107 if (ipv6_addr_is_multicast(&ipv6_hdr(skb
)->daddr
)) {
108 struct inet6_dev
*idev
= ip6_dst_idev(skb_dst(skb
));
110 if (!(dev
->flags
& IFF_LOOPBACK
) && sk_mc_loop(skb
->sk
) &&
111 ((mroute6_socket(dev_net(dev
), skb
) &&
112 !(IP6CB(skb
)->flags
& IP6SKB_FORWARDED
)) ||
113 ipv6_chk_mcast_addr(dev
, &ipv6_hdr(skb
)->daddr
,
114 &ipv6_hdr(skb
)->saddr
))) {
115 struct sk_buff
*newskb
= skb_clone(skb
, GFP_ATOMIC
);
117 /* Do not check for IFF_ALLMULTI; multicast routing
118 is not supported in any case.
121 NF_HOOK(NFPROTO_IPV6
, NF_INET_POST_ROUTING
,
122 newskb
, NULL
, newskb
->dev
,
123 ip6_dev_loopback_xmit
);
125 if (ipv6_hdr(skb
)->hop_limit
== 0) {
126 IP6_INC_STATS(dev_net(dev
), idev
,
127 IPSTATS_MIB_OUTDISCARDS
);
133 IP6_UPD_PO_STATS(dev_net(dev
), idev
, IPSTATS_MIB_OUTMCAST
,
138 return neigh_hh_output(dst
->hh
, skb
);
139 else if (dst
->neighbour
)
140 return dst
->neighbour
->output(skb
);
142 IP6_INC_STATS_BH(dev_net(dst
->dev
),
143 ip6_dst_idev(dst
), IPSTATS_MIB_OUTNOROUTES
);
148 static inline int ip6_skb_dst_mtu(struct sk_buff
*skb
)
150 struct ipv6_pinfo
*np
= skb
->sk
? inet6_sk(skb
->sk
) : NULL
;
152 return (np
&& np
->pmtudisc
== IPV6_PMTUDISC_PROBE
) ?
153 skb_dst(skb
)->dev
->mtu
: dst_mtu(skb_dst(skb
));
156 static int ip6_finish_output(struct sk_buff
*skb
)
158 if ((skb
->len
> ip6_skb_dst_mtu(skb
) && !skb_is_gso(skb
)) ||
159 dst_allfrag(skb_dst(skb
)))
160 return ip6_fragment(skb
, ip6_finish_output2
);
162 return ip6_finish_output2(skb
);
165 int ip6_output(struct sk_buff
*skb
)
167 struct net_device
*dev
= skb_dst(skb
)->dev
;
168 struct inet6_dev
*idev
= ip6_dst_idev(skb_dst(skb
));
169 if (unlikely(idev
->cnf
.disable_ipv6
)) {
170 IP6_INC_STATS(dev_net(dev
), idev
,
171 IPSTATS_MIB_OUTDISCARDS
);
176 return NF_HOOK_COND(NFPROTO_IPV6
, NF_INET_POST_ROUTING
, skb
, NULL
, dev
,
178 !(IP6CB(skb
)->flags
& IP6SKB_REROUTED
));
182 * xmit an sk_buff (used by TCP, SCTP and DCCP)
185 int ip6_xmit(struct sock
*sk
, struct sk_buff
*skb
, struct flowi
*fl
,
186 struct ipv6_txoptions
*opt
)
188 struct net
*net
= sock_net(sk
);
189 struct ipv6_pinfo
*np
= inet6_sk(sk
);
190 struct in6_addr
*first_hop
= &fl
->fl6_dst
;
191 struct dst_entry
*dst
= skb_dst(skb
);
193 u8 proto
= fl
->proto
;
194 int seg_len
= skb
->len
;
200 unsigned int head_room
;
202 /* First: exthdrs may take lots of space (~8K for now)
203 MAX_HEADER is not enough.
205 head_room
= opt
->opt_nflen
+ opt
->opt_flen
;
206 seg_len
+= head_room
;
207 head_room
+= sizeof(struct ipv6hdr
) + LL_RESERVED_SPACE(dst
->dev
);
209 if (skb_headroom(skb
) < head_room
) {
210 struct sk_buff
*skb2
= skb_realloc_headroom(skb
, head_room
);
212 IP6_INC_STATS(net
, ip6_dst_idev(skb_dst(skb
)),
213 IPSTATS_MIB_OUTDISCARDS
);
219 skb_set_owner_w(skb
, sk
);
222 ipv6_push_frag_opts(skb
, opt
, &proto
);
224 ipv6_push_nfrag_opts(skb
, opt
, &proto
, &first_hop
);
227 skb_push(skb
, sizeof(struct ipv6hdr
));
228 skb_reset_network_header(skb
);
232 * Fill in the IPv6 header
236 hlimit
= np
->hop_limit
;
239 hlimit
= ip6_dst_hoplimit(dst
);
241 *(__be32
*)hdr
= htonl(0x60000000 | (tclass
<< 20)) | fl
->fl6_flowlabel
;
243 hdr
->payload_len
= htons(seg_len
);
244 hdr
->nexthdr
= proto
;
245 hdr
->hop_limit
= hlimit
;
247 ipv6_addr_copy(&hdr
->saddr
, &fl
->fl6_src
);
248 ipv6_addr_copy(&hdr
->daddr
, first_hop
);
250 skb
->priority
= sk
->sk_priority
;
251 skb
->mark
= sk
->sk_mark
;
254 if ((skb
->len
<= mtu
) || skb
->local_df
|| skb_is_gso(skb
)) {
255 IP6_UPD_PO_STATS(net
, ip6_dst_idev(skb_dst(skb
)),
256 IPSTATS_MIB_OUT
, skb
->len
);
257 return NF_HOOK(NFPROTO_IPV6
, NF_INET_LOCAL_OUT
, skb
, NULL
,
258 dst
->dev
, dst_output
);
262 printk(KERN_DEBUG
"IPv6: sending pkt_too_big to self\n");
264 icmpv6_send(skb
, ICMPV6_PKT_TOOBIG
, 0, mtu
);
265 IP6_INC_STATS(net
, ip6_dst_idev(skb_dst(skb
)), IPSTATS_MIB_FRAGFAILS
);
270 EXPORT_SYMBOL(ip6_xmit
);
273 * To avoid extra problems ND packets are send through this
274 * routine. It's code duplication but I really want to avoid
275 * extra checks since ipv6_build_header is used by TCP (which
276 * is for us performance critical)
279 int ip6_nd_hdr(struct sock
*sk
, struct sk_buff
*skb
, struct net_device
*dev
,
280 const struct in6_addr
*saddr
, const struct in6_addr
*daddr
,
283 struct ipv6_pinfo
*np
= inet6_sk(sk
);
287 skb
->protocol
= htons(ETH_P_IPV6
);
290 totlen
= len
+ sizeof(struct ipv6hdr
);
292 skb_reset_network_header(skb
);
293 skb_put(skb
, sizeof(struct ipv6hdr
));
296 *(__be32
*)hdr
= htonl(0x60000000);
298 hdr
->payload_len
= htons(len
);
299 hdr
->nexthdr
= proto
;
300 hdr
->hop_limit
= np
->hop_limit
;
302 ipv6_addr_copy(&hdr
->saddr
, saddr
);
303 ipv6_addr_copy(&hdr
->daddr
, daddr
);
308 static int ip6_call_ra_chain(struct sk_buff
*skb
, int sel
)
310 struct ip6_ra_chain
*ra
;
311 struct sock
*last
= NULL
;
313 read_lock(&ip6_ra_lock
);
314 for (ra
= ip6_ra_chain
; ra
; ra
= ra
->next
) {
315 struct sock
*sk
= ra
->sk
;
316 if (sk
&& ra
->sel
== sel
&&
317 (!sk
->sk_bound_dev_if
||
318 sk
->sk_bound_dev_if
== skb
->dev
->ifindex
)) {
320 struct sk_buff
*skb2
= skb_clone(skb
, GFP_ATOMIC
);
322 rawv6_rcv(last
, skb2
);
329 rawv6_rcv(last
, skb
);
330 read_unlock(&ip6_ra_lock
);
333 read_unlock(&ip6_ra_lock
);
337 static int ip6_forward_proxy_check(struct sk_buff
*skb
)
339 struct ipv6hdr
*hdr
= ipv6_hdr(skb
);
340 u8 nexthdr
= hdr
->nexthdr
;
343 if (ipv6_ext_hdr(nexthdr
)) {
344 offset
= ipv6_skip_exthdr(skb
, sizeof(*hdr
), &nexthdr
);
348 offset
= sizeof(struct ipv6hdr
);
350 if (nexthdr
== IPPROTO_ICMPV6
) {
351 struct icmp6hdr
*icmp6
;
353 if (!pskb_may_pull(skb
, (skb_network_header(skb
) +
354 offset
+ 1 - skb
->data
)))
357 icmp6
= (struct icmp6hdr
*)(skb_network_header(skb
) + offset
);
359 switch (icmp6
->icmp6_type
) {
360 case NDISC_ROUTER_SOLICITATION
:
361 case NDISC_ROUTER_ADVERTISEMENT
:
362 case NDISC_NEIGHBOUR_SOLICITATION
:
363 case NDISC_NEIGHBOUR_ADVERTISEMENT
:
365 /* For reaction involving unicast neighbor discovery
366 * message destined to the proxied address, pass it to
376 * The proxying router can't forward traffic sent to a link-local
377 * address, so signal the sender and discard the packet. This
378 * behavior is clarified by the MIPv6 specification.
380 if (ipv6_addr_type(&hdr
->daddr
) & IPV6_ADDR_LINKLOCAL
) {
381 dst_link_failure(skb
);
388 static inline int ip6_forward_finish(struct sk_buff
*skb
)
390 return dst_output(skb
);
393 int ip6_forward(struct sk_buff
*skb
)
395 struct dst_entry
*dst
= skb_dst(skb
);
396 struct ipv6hdr
*hdr
= ipv6_hdr(skb
);
397 struct inet6_skb_parm
*opt
= IP6CB(skb
);
398 struct net
*net
= dev_net(dst
->dev
);
401 if (net
->ipv6
.devconf_all
->forwarding
== 0)
404 if (skb_warn_if_lro(skb
))
407 if (!xfrm6_policy_check(NULL
, XFRM_POLICY_FWD
, skb
)) {
408 IP6_INC_STATS(net
, ip6_dst_idev(dst
), IPSTATS_MIB_INDISCARDS
);
412 skb_forward_csum(skb
);
415 * We DO NOT make any processing on
416 * RA packets, pushing them to user level AS IS
417 * without ane WARRANTY that application will be able
418 * to interpret them. The reason is that we
419 * cannot make anything clever here.
421 * We are not end-node, so that if packet contains
422 * AH/ESP, we cannot make anything.
423 * Defragmentation also would be mistake, RA packets
424 * cannot be fragmented, because there is no warranty
425 * that different fragments will go along one path. --ANK
428 u8
*ptr
= skb_network_header(skb
) + opt
->ra
;
429 if (ip6_call_ra_chain(skb
, (ptr
[2]<<8) + ptr
[3]))
434 * check and decrement ttl
436 if (hdr
->hop_limit
<= 1) {
437 /* Force OUTPUT device used as source address */
439 icmpv6_send(skb
, ICMPV6_TIME_EXCEED
, ICMPV6_EXC_HOPLIMIT
, 0);
440 IP6_INC_STATS_BH(net
,
441 ip6_dst_idev(dst
), IPSTATS_MIB_INHDRERRORS
);
447 /* XXX: idev->cnf.proxy_ndp? */
448 if (net
->ipv6
.devconf_all
->proxy_ndp
&&
449 pneigh_lookup(&nd_tbl
, net
, &hdr
->daddr
, skb
->dev
, 0)) {
450 int proxied
= ip6_forward_proxy_check(skb
);
452 return ip6_input(skb
);
453 else if (proxied
< 0) {
454 IP6_INC_STATS(net
, ip6_dst_idev(dst
),
455 IPSTATS_MIB_INDISCARDS
);
460 if (!xfrm6_route_forward(skb
)) {
461 IP6_INC_STATS(net
, ip6_dst_idev(dst
), IPSTATS_MIB_INDISCARDS
);
466 /* IPv6 specs say nothing about it, but it is clear that we cannot
467 send redirects to source routed frames.
468 We don't send redirects to frames decapsulated from IPsec.
470 if (skb
->dev
== dst
->dev
&& dst
->neighbour
&& opt
->srcrt
== 0 &&
471 !skb_sec_path(skb
)) {
472 struct in6_addr
*target
= NULL
;
474 struct neighbour
*n
= dst
->neighbour
;
477 * incoming and outgoing devices are the same
481 rt
= (struct rt6_info
*) dst
;
482 if ((rt
->rt6i_flags
& RTF_GATEWAY
))
483 target
= (struct in6_addr
*)&n
->primary_key
;
485 target
= &hdr
->daddr
;
487 /* Limit redirects both by destination (here)
488 and by source (inside ndisc_send_redirect)
490 if (xrlim_allow(dst
, 1*HZ
))
491 ndisc_send_redirect(skb
, n
, target
);
493 int addrtype
= ipv6_addr_type(&hdr
->saddr
);
495 /* This check is security critical. */
496 if (addrtype
== IPV6_ADDR_ANY
||
497 addrtype
& (IPV6_ADDR_MULTICAST
| IPV6_ADDR_LOOPBACK
))
499 if (addrtype
& IPV6_ADDR_LINKLOCAL
) {
500 icmpv6_send(skb
, ICMPV6_DEST_UNREACH
,
501 ICMPV6_NOT_NEIGHBOUR
, 0);
507 if (mtu
< IPV6_MIN_MTU
)
510 if (skb
->len
> mtu
&& !skb_is_gso(skb
)) {
511 /* Again, force OUTPUT device used as source address */
513 icmpv6_send(skb
, ICMPV6_PKT_TOOBIG
, 0, mtu
);
514 IP6_INC_STATS_BH(net
,
515 ip6_dst_idev(dst
), IPSTATS_MIB_INTOOBIGERRORS
);
516 IP6_INC_STATS_BH(net
,
517 ip6_dst_idev(dst
), IPSTATS_MIB_FRAGFAILS
);
522 if (skb_cow(skb
, dst
->dev
->hard_header_len
)) {
523 IP6_INC_STATS(net
, ip6_dst_idev(dst
), IPSTATS_MIB_OUTDISCARDS
);
529 /* Mangling hops number delayed to point after skb COW */
533 IP6_INC_STATS_BH(net
, ip6_dst_idev(dst
), IPSTATS_MIB_OUTFORWDATAGRAMS
);
534 return NF_HOOK(NFPROTO_IPV6
, NF_INET_FORWARD
, skb
, skb
->dev
, dst
->dev
,
538 IP6_INC_STATS_BH(net
, ip6_dst_idev(dst
), IPSTATS_MIB_INADDRERRORS
);
544 static void ip6_copy_metadata(struct sk_buff
*to
, struct sk_buff
*from
)
546 to
->pkt_type
= from
->pkt_type
;
547 to
->priority
= from
->priority
;
548 to
->protocol
= from
->protocol
;
550 skb_dst_set(to
, dst_clone(skb_dst(from
)));
552 to
->mark
= from
->mark
;
554 #ifdef CONFIG_NET_SCHED
555 to
->tc_index
= from
->tc_index
;
558 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
559 defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
560 to
->nf_trace
= from
->nf_trace
;
562 skb_copy_secmark(to
, from
);
565 int ip6_find_1stfragopt(struct sk_buff
*skb
, u8
**nexthdr
)
567 u16 offset
= sizeof(struct ipv6hdr
);
568 struct ipv6_opt_hdr
*exthdr
=
569 (struct ipv6_opt_hdr
*)(ipv6_hdr(skb
) + 1);
570 unsigned int packet_len
= skb
->tail
- skb
->network_header
;
572 *nexthdr
= &ipv6_hdr(skb
)->nexthdr
;
574 while (offset
+ 1 <= packet_len
) {
580 case NEXTHDR_ROUTING
:
584 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
585 if (ipv6_find_tlv(skb
, offset
, IPV6_TLV_HAO
) >= 0)
595 offset
+= ipv6_optlen(exthdr
);
596 *nexthdr
= &exthdr
->nexthdr
;
597 exthdr
= (struct ipv6_opt_hdr
*)(skb_network_header(skb
) +
604 static int ip6_fragment(struct sk_buff
*skb
, int (*output
)(struct sk_buff
*))
606 struct sk_buff
*frag
;
607 struct rt6_info
*rt
= (struct rt6_info
*)skb_dst(skb
);
608 struct ipv6_pinfo
*np
= skb
->sk
? inet6_sk(skb
->sk
) : NULL
;
609 struct ipv6hdr
*tmp_hdr
;
611 unsigned int mtu
, hlen
, left
, len
;
613 int ptr
, offset
= 0, err
=0;
614 u8
*prevhdr
, nexthdr
= 0;
615 struct net
*net
= dev_net(skb_dst(skb
)->dev
);
617 hlen
= ip6_find_1stfragopt(skb
, &prevhdr
);
620 mtu
= ip6_skb_dst_mtu(skb
);
622 /* We must not fragment if the socket is set to force MTU discovery
623 * or if the skb it not generated by a local socket.
625 if (!skb
->local_df
&& skb
->len
> mtu
) {
626 skb
->dev
= skb_dst(skb
)->dev
;
627 icmpv6_send(skb
, ICMPV6_PKT_TOOBIG
, 0, mtu
);
628 IP6_INC_STATS(net
, ip6_dst_idev(skb_dst(skb
)),
629 IPSTATS_MIB_FRAGFAILS
);
634 if (np
&& np
->frag_size
< mtu
) {
638 mtu
-= hlen
+ sizeof(struct frag_hdr
);
640 if (skb_has_frags(skb
)) {
641 int first_len
= skb_pagelen(skb
);
644 if (first_len
- hlen
> mtu
||
645 ((first_len
- hlen
) & 7) ||
649 skb_walk_frags(skb
, frag
) {
650 /* Correct geometry. */
651 if (frag
->len
> mtu
||
652 ((frag
->len
& 7) && frag
->next
) ||
653 skb_headroom(frag
) < hlen
)
656 /* Partially cloned skb? */
657 if (skb_shared(frag
))
663 frag
->destructor
= sock_wfree
;
664 truesizes
+= frag
->truesize
;
670 frag
= skb_shinfo(skb
)->frag_list
;
671 skb_frag_list_init(skb
);
674 *prevhdr
= NEXTHDR_FRAGMENT
;
675 tmp_hdr
= kmemdup(skb_network_header(skb
), hlen
, GFP_ATOMIC
);
677 IP6_INC_STATS(net
, ip6_dst_idev(skb_dst(skb
)),
678 IPSTATS_MIB_FRAGFAILS
);
682 __skb_pull(skb
, hlen
);
683 fh
= (struct frag_hdr
*)__skb_push(skb
, sizeof(struct frag_hdr
));
684 __skb_push(skb
, hlen
);
685 skb_reset_network_header(skb
);
686 memcpy(skb_network_header(skb
), tmp_hdr
, hlen
);
688 ipv6_select_ident(fh
);
689 fh
->nexthdr
= nexthdr
;
691 fh
->frag_off
= htons(IP6_MF
);
692 frag_id
= fh
->identification
;
694 first_len
= skb_pagelen(skb
);
695 skb
->data_len
= first_len
- skb_headlen(skb
);
696 skb
->truesize
-= truesizes
;
697 skb
->len
= first_len
;
698 ipv6_hdr(skb
)->payload_len
= htons(first_len
-
699 sizeof(struct ipv6hdr
));
704 /* Prepare header of the next frame,
705 * before previous one went down. */
707 frag
->ip_summed
= CHECKSUM_NONE
;
708 skb_reset_transport_header(frag
);
709 fh
= (struct frag_hdr
*)__skb_push(frag
, sizeof(struct frag_hdr
));
710 __skb_push(frag
, hlen
);
711 skb_reset_network_header(frag
);
712 memcpy(skb_network_header(frag
), tmp_hdr
,
714 offset
+= skb
->len
- hlen
- sizeof(struct frag_hdr
);
715 fh
->nexthdr
= nexthdr
;
717 fh
->frag_off
= htons(offset
);
718 if (frag
->next
!= NULL
)
719 fh
->frag_off
|= htons(IP6_MF
);
720 fh
->identification
= frag_id
;
721 ipv6_hdr(frag
)->payload_len
=
723 sizeof(struct ipv6hdr
));
724 ip6_copy_metadata(frag
, skb
);
729 IP6_INC_STATS(net
, ip6_dst_idev(&rt
->dst
),
730 IPSTATS_MIB_FRAGCREATES
);
743 IP6_INC_STATS(net
, ip6_dst_idev(&rt
->dst
),
744 IPSTATS_MIB_FRAGOKS
);
745 dst_release(&rt
->dst
);
755 IP6_INC_STATS(net
, ip6_dst_idev(&rt
->dst
),
756 IPSTATS_MIB_FRAGFAILS
);
757 dst_release(&rt
->dst
);
762 left
= skb
->len
- hlen
; /* Space per frame */
763 ptr
= hlen
; /* Where to start from */
766 * Fragment the datagram.
769 *prevhdr
= NEXTHDR_FRAGMENT
;
772 * Keep copying data until we run out.
776 /* IF: it doesn't fit, use 'mtu' - the data space left */
779 /* IF: we are not sending upto and including the packet end
780 then align the next start on an eight byte boundary */
788 if ((frag
= alloc_skb(len
+hlen
+sizeof(struct frag_hdr
)+LL_ALLOCATED_SPACE(rt
->dst
.dev
), GFP_ATOMIC
)) == NULL
) {
789 NETDEBUG(KERN_INFO
"IPv6: frag: no memory for new fragment!\n");
790 IP6_INC_STATS(net
, ip6_dst_idev(skb_dst(skb
)),
791 IPSTATS_MIB_FRAGFAILS
);
797 * Set up data on packet
800 ip6_copy_metadata(frag
, skb
);
801 skb_reserve(frag
, LL_RESERVED_SPACE(rt
->dst
.dev
));
802 skb_put(frag
, len
+ hlen
+ sizeof(struct frag_hdr
));
803 skb_reset_network_header(frag
);
804 fh
= (struct frag_hdr
*)(skb_network_header(frag
) + hlen
);
805 frag
->transport_header
= (frag
->network_header
+ hlen
+
806 sizeof(struct frag_hdr
));
809 * Charge the memory for the fragment to any owner
813 skb_set_owner_w(frag
, skb
->sk
);
816 * Copy the packet header into the new buffer.
818 skb_copy_from_linear_data(skb
, skb_network_header(frag
), hlen
);
821 * Build fragment header.
823 fh
->nexthdr
= nexthdr
;
826 ipv6_select_ident(fh
);
827 frag_id
= fh
->identification
;
829 fh
->identification
= frag_id
;
832 * Copy a block of the IP datagram.
834 if (skb_copy_bits(skb
, ptr
, skb_transport_header(frag
), len
))
838 fh
->frag_off
= htons(offset
);
840 fh
->frag_off
|= htons(IP6_MF
);
841 ipv6_hdr(frag
)->payload_len
= htons(frag
->len
-
842 sizeof(struct ipv6hdr
));
848 * Put this fragment into the sending queue.
854 IP6_INC_STATS(net
, ip6_dst_idev(skb_dst(skb
)),
855 IPSTATS_MIB_FRAGCREATES
);
857 IP6_INC_STATS(net
, ip6_dst_idev(skb_dst(skb
)),
858 IPSTATS_MIB_FRAGOKS
);
863 IP6_INC_STATS(net
, ip6_dst_idev(skb_dst(skb
)),
864 IPSTATS_MIB_FRAGFAILS
);
869 static inline int ip6_rt_check(struct rt6key
*rt_key
,
870 struct in6_addr
*fl_addr
,
871 struct in6_addr
*addr_cache
)
873 return ((rt_key
->plen
!= 128 || !ipv6_addr_equal(fl_addr
, &rt_key
->addr
)) &&
874 (addr_cache
== NULL
|| !ipv6_addr_equal(fl_addr
, addr_cache
)));
877 static struct dst_entry
*ip6_sk_dst_check(struct sock
*sk
,
878 struct dst_entry
*dst
,
881 struct ipv6_pinfo
*np
= inet6_sk(sk
);
882 struct rt6_info
*rt
= (struct rt6_info
*)dst
;
887 /* Yes, checking route validity in not connected
888 * case is not very simple. Take into account,
889 * that we do not support routing by source, TOS,
890 * and MSG_DONTROUTE --ANK (980726)
892 * 1. ip6_rt_check(): If route was host route,
893 * check that cached destination is current.
894 * If it is network route, we still may
895 * check its validity using saved pointer
896 * to the last used address: daddr_cache.
897 * We do not want to save whole address now,
898 * (because main consumer of this service
899 * is tcp, which has not this problem),
900 * so that the last trick works only on connected
902 * 2. oif also should be the same.
904 if (ip6_rt_check(&rt
->rt6i_dst
, &fl
->fl6_dst
, np
->daddr_cache
) ||
905 #ifdef CONFIG_IPV6_SUBTREES
906 ip6_rt_check(&rt
->rt6i_src
, &fl
->fl6_src
, np
->saddr_cache
) ||
908 (fl
->oif
&& fl
->oif
!= dst
->dev
->ifindex
)) {
917 static int ip6_dst_lookup_tail(struct sock
*sk
,
918 struct dst_entry
**dst
, struct flowi
*fl
)
921 struct net
*net
= sock_net(sk
);
924 *dst
= ip6_route_output(net
, sk
, fl
);
926 if ((err
= (*dst
)->error
))
927 goto out_err_release
;
929 if (ipv6_addr_any(&fl
->fl6_src
)) {
930 err
= ipv6_dev_get_saddr(net
, ip6_dst_idev(*dst
)->dev
,
932 sk
? inet6_sk(sk
)->srcprefs
: 0,
935 goto out_err_release
;
938 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
940 * Here if the dst entry we've looked up
941 * has a neighbour entry that is in the INCOMPLETE
942 * state and the src address from the flow is
943 * marked as OPTIMISTIC, we release the found
944 * dst entry and replace it instead with the
945 * dst entry of the nexthop router
947 if ((*dst
)->neighbour
&& !((*dst
)->neighbour
->nud_state
& NUD_VALID
)) {
948 struct inet6_ifaddr
*ifp
;
952 ifp
= ipv6_get_ifaddr(net
, &fl
->fl6_src
,
955 redirect
= (ifp
&& ifp
->flags
& IFA_F_OPTIMISTIC
);
961 * We need to get the dst entry for the
962 * default router instead
965 memcpy(&fl_gw
, fl
, sizeof(struct flowi
));
966 memset(&fl_gw
.fl6_dst
, 0, sizeof(struct in6_addr
));
967 *dst
= ip6_route_output(net
, sk
, &fl_gw
);
968 if ((err
= (*dst
)->error
))
969 goto out_err_release
;
977 if (err
== -ENETUNREACH
)
978 IP6_INC_STATS_BH(net
, NULL
, IPSTATS_MIB_OUTNOROUTES
);
985 * ip6_dst_lookup - perform route lookup on flow
986 * @sk: socket which provides route info
987 * @dst: pointer to dst_entry * for result
988 * @fl: flow to lookup
990 * This function performs a route lookup on the given flow.
992 * It returns zero on success, or a standard errno code on error.
994 int ip6_dst_lookup(struct sock
*sk
, struct dst_entry
**dst
, struct flowi
*fl
)
997 return ip6_dst_lookup_tail(sk
, dst
, fl
);
999 EXPORT_SYMBOL_GPL(ip6_dst_lookup
);
1002 * ip6_sk_dst_lookup - perform socket cached route lookup on flow
1003 * @sk: socket which provides the dst cache and route info
1004 * @dst: pointer to dst_entry * for result
1005 * @fl: flow to lookup
1007 * This function performs a route lookup on the given flow with the
1008 * possibility of using the cached route in the socket if it is valid.
1009 * It will take the socket dst lock when operating on the dst cache.
1010 * As a result, this function can only be used in process context.
1012 * It returns zero on success, or a standard errno code on error.
1014 int ip6_sk_dst_lookup(struct sock
*sk
, struct dst_entry
**dst
, struct flowi
*fl
)
1018 *dst
= sk_dst_check(sk
, inet6_sk(sk
)->dst_cookie
);
1019 *dst
= ip6_sk_dst_check(sk
, *dst
, fl
);
1022 return ip6_dst_lookup_tail(sk
, dst
, fl
);
1024 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup
);
1026 static inline int ip6_ufo_append_data(struct sock
*sk
,
1027 int getfrag(void *from
, char *to
, int offset
, int len
,
1028 int odd
, struct sk_buff
*skb
),
1029 void *from
, int length
, int hh_len
, int fragheaderlen
,
1030 int transhdrlen
, int mtu
,unsigned int flags
)
1033 struct sk_buff
*skb
;
1036 /* There is support for UDP large send offload by network
1037 * device, so create one single skb packet containing complete
1040 if ((skb
= skb_peek_tail(&sk
->sk_write_queue
)) == NULL
) {
1041 skb
= sock_alloc_send_skb(sk
,
1042 hh_len
+ fragheaderlen
+ transhdrlen
+ 20,
1043 (flags
& MSG_DONTWAIT
), &err
);
1047 /* reserve space for Hardware header */
1048 skb_reserve(skb
, hh_len
);
1050 /* create space for UDP/IP header */
1051 skb_put(skb
,fragheaderlen
+ transhdrlen
);
1053 /* initialize network header pointer */
1054 skb_reset_network_header(skb
);
1056 /* initialize protocol header pointer */
1057 skb
->transport_header
= skb
->network_header
+ fragheaderlen
;
1059 skb
->ip_summed
= CHECKSUM_PARTIAL
;
1061 sk
->sk_sndmsg_off
= 0;
1064 err
= skb_append_datato_frags(sk
,skb
, getfrag
, from
,
1065 (length
- transhdrlen
));
1067 struct frag_hdr fhdr
;
1069 /* Specify the length of each IPv6 datagram fragment.
1070 * It has to be a multiple of 8.
1072 skb_shinfo(skb
)->gso_size
= (mtu
- fragheaderlen
-
1073 sizeof(struct frag_hdr
)) & ~7;
1074 skb_shinfo(skb
)->gso_type
= SKB_GSO_UDP
;
1075 ipv6_select_ident(&fhdr
);
1076 skb_shinfo(skb
)->ip6_frag_id
= fhdr
.identification
;
1077 __skb_queue_tail(&sk
->sk_write_queue
, skb
);
1081 /* There is not enough support do UPD LSO,
1082 * so follow normal path
1089 static inline struct ipv6_opt_hdr
*ip6_opt_dup(struct ipv6_opt_hdr
*src
,
1092 return src
? kmemdup(src
, (src
->hdrlen
+ 1) * 8, gfp
) : NULL
;
1095 static inline struct ipv6_rt_hdr
*ip6_rthdr_dup(struct ipv6_rt_hdr
*src
,
1098 return src
? kmemdup(src
, (src
->hdrlen
+ 1) * 8, gfp
) : NULL
;
1101 int ip6_append_data(struct sock
*sk
, int getfrag(void *from
, char *to
,
1102 int offset
, int len
, int odd
, struct sk_buff
*skb
),
1103 void *from
, int length
, int transhdrlen
,
1104 int hlimit
, int tclass
, struct ipv6_txoptions
*opt
, struct flowi
*fl
,
1105 struct rt6_info
*rt
, unsigned int flags
, int dontfrag
)
1107 struct inet_sock
*inet
= inet_sk(sk
);
1108 struct ipv6_pinfo
*np
= inet6_sk(sk
);
1109 struct sk_buff
*skb
;
1110 unsigned int maxfraglen
, fragheaderlen
;
1117 int csummode
= CHECKSUM_NONE
;
1119 if (flags
&MSG_PROBE
)
1121 if (skb_queue_empty(&sk
->sk_write_queue
)) {
1126 if (WARN_ON(np
->cork
.opt
))
1129 np
->cork
.opt
= kmalloc(opt
->tot_len
, sk
->sk_allocation
);
1130 if (unlikely(np
->cork
.opt
== NULL
))
1133 np
->cork
.opt
->tot_len
= opt
->tot_len
;
1134 np
->cork
.opt
->opt_flen
= opt
->opt_flen
;
1135 np
->cork
.opt
->opt_nflen
= opt
->opt_nflen
;
1137 np
->cork
.opt
->dst0opt
= ip6_opt_dup(opt
->dst0opt
,
1139 if (opt
->dst0opt
&& !np
->cork
.opt
->dst0opt
)
1142 np
->cork
.opt
->dst1opt
= ip6_opt_dup(opt
->dst1opt
,
1144 if (opt
->dst1opt
&& !np
->cork
.opt
->dst1opt
)
1147 np
->cork
.opt
->hopopt
= ip6_opt_dup(opt
->hopopt
,
1149 if (opt
->hopopt
&& !np
->cork
.opt
->hopopt
)
1152 np
->cork
.opt
->srcrt
= ip6_rthdr_dup(opt
->srcrt
,
1154 if (opt
->srcrt
&& !np
->cork
.opt
->srcrt
)
1157 /* need source address above miyazawa*/
1160 inet
->cork
.dst
= &rt
->dst
;
1161 inet
->cork
.fl
= *fl
;
1162 np
->cork
.hop_limit
= hlimit
;
1163 np
->cork
.tclass
= tclass
;
1164 mtu
= np
->pmtudisc
== IPV6_PMTUDISC_PROBE
?
1165 rt
->dst
.dev
->mtu
: dst_mtu(rt
->dst
.path
);
1166 if (np
->frag_size
< mtu
) {
1168 mtu
= np
->frag_size
;
1170 inet
->cork
.fragsize
= mtu
;
1171 if (dst_allfrag(rt
->dst
.path
))
1172 inet
->cork
.flags
|= IPCORK_ALLFRAG
;
1173 inet
->cork
.length
= 0;
1174 sk
->sk_sndmsg_page
= NULL
;
1175 sk
->sk_sndmsg_off
= 0;
1176 exthdrlen
= rt
->dst
.header_len
+ (opt
? opt
->opt_flen
: 0) -
1177 rt
->rt6i_nfheader_len
;
1178 length
+= exthdrlen
;
1179 transhdrlen
+= exthdrlen
;
1181 rt
= (struct rt6_info
*)inet
->cork
.dst
;
1182 fl
= &inet
->cork
.fl
;
1186 mtu
= inet
->cork
.fragsize
;
1189 hh_len
= LL_RESERVED_SPACE(rt
->dst
.dev
);
1191 fragheaderlen
= sizeof(struct ipv6hdr
) + rt
->rt6i_nfheader_len
+
1192 (opt
? opt
->opt_nflen
: 0);
1193 maxfraglen
= ((mtu
- fragheaderlen
) & ~7) + fragheaderlen
- sizeof(struct frag_hdr
);
1195 if (mtu
<= sizeof(struct ipv6hdr
) + IPV6_MAXPLEN
) {
1196 if (inet
->cork
.length
+ length
> sizeof(struct ipv6hdr
) + IPV6_MAXPLEN
- fragheaderlen
) {
1197 ipv6_local_error(sk
, EMSGSIZE
, fl
, mtu
-exthdrlen
);
1203 * Let's try using as much space as possible.
1204 * Use MTU if total length of the message fits into the MTU.
1205 * Otherwise, we need to reserve fragment header and
1206 * fragment alignment (= 8-15 octects, in total).
1208 * Note that we may need to "move" the data from the tail of
1209 * of the buffer to the new fragment when we split
1212 * FIXME: It may be fragmented into multiple chunks
1213 * at once if non-fragmentable extension headers
1218 inet
->cork
.length
+= length
;
1220 int proto
= sk
->sk_protocol
;
1221 if (dontfrag
&& (proto
== IPPROTO_UDP
|| proto
== IPPROTO_RAW
)){
1222 ipv6_local_rxpmtu(sk
, fl
, mtu
-exthdrlen
);
1226 if (proto
== IPPROTO_UDP
&&
1227 (rt
->dst
.dev
->features
& NETIF_F_UFO
)) {
1229 err
= ip6_ufo_append_data(sk
, getfrag
, from
, length
,
1230 hh_len
, fragheaderlen
,
1231 transhdrlen
, mtu
, flags
);
1238 if ((skb
= skb_peek_tail(&sk
->sk_write_queue
)) == NULL
)
1241 while (length
> 0) {
1242 /* Check if the remaining data fits into current packet. */
1243 copy
= (inet
->cork
.length
<= mtu
&& !(inet
->cork
.flags
& IPCORK_ALLFRAG
) ? mtu
: maxfraglen
) - skb
->len
;
1245 copy
= maxfraglen
- skb
->len
;
1249 unsigned int datalen
;
1250 unsigned int fraglen
;
1251 unsigned int fraggap
;
1252 unsigned int alloclen
;
1253 struct sk_buff
*skb_prev
;
1257 /* There's no room in the current skb */
1259 fraggap
= skb_prev
->len
- maxfraglen
;
1264 * If remaining data exceeds the mtu,
1265 * we know we need more fragment(s).
1267 datalen
= length
+ fraggap
;
1268 if (datalen
> (inet
->cork
.length
<= mtu
&& !(inet
->cork
.flags
& IPCORK_ALLFRAG
) ? mtu
: maxfraglen
) - fragheaderlen
)
1269 datalen
= maxfraglen
- fragheaderlen
;
1271 fraglen
= datalen
+ fragheaderlen
;
1272 if ((flags
& MSG_MORE
) &&
1273 !(rt
->dst
.dev
->features
&NETIF_F_SG
))
1276 alloclen
= datalen
+ fragheaderlen
;
1279 * The last fragment gets additional space at tail.
1280 * Note: we overallocate on fragments with MSG_MODE
1281 * because we have no idea if we're the last one.
1283 if (datalen
== length
+ fraggap
)
1284 alloclen
+= rt
->dst
.trailer_len
;
1287 * We just reserve space for fragment header.
1288 * Note: this may be overallocation if the message
1289 * (without MSG_MORE) fits into the MTU.
1291 alloclen
+= sizeof(struct frag_hdr
);
1294 skb
= sock_alloc_send_skb(sk
,
1296 (flags
& MSG_DONTWAIT
), &err
);
1299 if (atomic_read(&sk
->sk_wmem_alloc
) <=
1301 skb
= sock_wmalloc(sk
,
1302 alloclen
+ hh_len
, 1,
1304 if (unlikely(skb
== NULL
))
1310 * Fill in the control structures
1312 skb
->ip_summed
= csummode
;
1314 /* reserve for fragmentation */
1315 skb_reserve(skb
, hh_len
+sizeof(struct frag_hdr
));
1318 * Find where to start putting bytes
1320 data
= skb_put(skb
, fraglen
);
1321 skb_set_network_header(skb
, exthdrlen
);
1322 data
+= fragheaderlen
;
1323 skb
->transport_header
= (skb
->network_header
+
1326 skb
->csum
= skb_copy_and_csum_bits(
1327 skb_prev
, maxfraglen
,
1328 data
+ transhdrlen
, fraggap
, 0);
1329 skb_prev
->csum
= csum_sub(skb_prev
->csum
,
1332 pskb_trim_unique(skb_prev
, maxfraglen
);
1334 copy
= datalen
- transhdrlen
- fraggap
;
1339 } else if (copy
> 0 && getfrag(from
, data
+ transhdrlen
, offset
, copy
, fraggap
, skb
) < 0) {
1346 length
-= datalen
- fraggap
;
1349 csummode
= CHECKSUM_NONE
;
1352 * Put the packet on the pending queue
1354 __skb_queue_tail(&sk
->sk_write_queue
, skb
);
1361 if (!(rt
->dst
.dev
->features
&NETIF_F_SG
)) {
1365 if (getfrag(from
, skb_put(skb
, copy
),
1366 offset
, copy
, off
, skb
) < 0) {
1367 __skb_trim(skb
, off
);
1372 int i
= skb_shinfo(skb
)->nr_frags
;
1373 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
-1];
1374 struct page
*page
= sk
->sk_sndmsg_page
;
1375 int off
= sk
->sk_sndmsg_off
;
1378 if (page
&& (left
= PAGE_SIZE
- off
) > 0) {
1381 if (page
!= frag
->page
) {
1382 if (i
== MAX_SKB_FRAGS
) {
1387 skb_fill_page_desc(skb
, i
, page
, sk
->sk_sndmsg_off
, 0);
1388 frag
= &skb_shinfo(skb
)->frags
[i
];
1390 } else if(i
< MAX_SKB_FRAGS
) {
1391 if (copy
> PAGE_SIZE
)
1393 page
= alloc_pages(sk
->sk_allocation
, 0);
1398 sk
->sk_sndmsg_page
= page
;
1399 sk
->sk_sndmsg_off
= 0;
1401 skb_fill_page_desc(skb
, i
, page
, 0, 0);
1402 frag
= &skb_shinfo(skb
)->frags
[i
];
1407 if (getfrag(from
, page_address(frag
->page
)+frag
->page_offset
+frag
->size
, offset
, copy
, skb
->len
, skb
) < 0) {
1411 sk
->sk_sndmsg_off
+= copy
;
1414 skb
->data_len
+= copy
;
1415 skb
->truesize
+= copy
;
1416 atomic_add(copy
, &sk
->sk_wmem_alloc
);
1423 inet
->cork
.length
-= length
;
1424 IP6_INC_STATS(sock_net(sk
), rt
->rt6i_idev
, IPSTATS_MIB_OUTDISCARDS
);
1428 static void ip6_cork_release(struct inet_sock
*inet
, struct ipv6_pinfo
*np
)
1431 kfree(np
->cork
.opt
->dst0opt
);
1432 kfree(np
->cork
.opt
->dst1opt
);
1433 kfree(np
->cork
.opt
->hopopt
);
1434 kfree(np
->cork
.opt
->srcrt
);
1435 kfree(np
->cork
.opt
);
1436 np
->cork
.opt
= NULL
;
1439 if (inet
->cork
.dst
) {
1440 dst_release(inet
->cork
.dst
);
1441 inet
->cork
.dst
= NULL
;
1442 inet
->cork
.flags
&= ~IPCORK_ALLFRAG
;
1444 memset(&inet
->cork
.fl
, 0, sizeof(inet
->cork
.fl
));
1447 int ip6_push_pending_frames(struct sock
*sk
)
1449 struct sk_buff
*skb
, *tmp_skb
;
1450 struct sk_buff
**tail_skb
;
1451 struct in6_addr final_dst_buf
, *final_dst
= &final_dst_buf
;
1452 struct inet_sock
*inet
= inet_sk(sk
);
1453 struct ipv6_pinfo
*np
= inet6_sk(sk
);
1454 struct net
*net
= sock_net(sk
);
1455 struct ipv6hdr
*hdr
;
1456 struct ipv6_txoptions
*opt
= np
->cork
.opt
;
1457 struct rt6_info
*rt
= (struct rt6_info
*)inet
->cork
.dst
;
1458 struct flowi
*fl
= &inet
->cork
.fl
;
1459 unsigned char proto
= fl
->proto
;
1462 if ((skb
= __skb_dequeue(&sk
->sk_write_queue
)) == NULL
)
1464 tail_skb
= &(skb_shinfo(skb
)->frag_list
);
1466 /* move skb->data to ip header from ext header */
1467 if (skb
->data
< skb_network_header(skb
))
1468 __skb_pull(skb
, skb_network_offset(skb
));
1469 while ((tmp_skb
= __skb_dequeue(&sk
->sk_write_queue
)) != NULL
) {
1470 __skb_pull(tmp_skb
, skb_network_header_len(skb
));
1471 *tail_skb
= tmp_skb
;
1472 tail_skb
= &(tmp_skb
->next
);
1473 skb
->len
+= tmp_skb
->len
;
1474 skb
->data_len
+= tmp_skb
->len
;
1475 skb
->truesize
+= tmp_skb
->truesize
;
1476 tmp_skb
->destructor
= NULL
;
1480 /* Allow local fragmentation. */
1481 if (np
->pmtudisc
< IPV6_PMTUDISC_DO
)
1484 ipv6_addr_copy(final_dst
, &fl
->fl6_dst
);
1485 __skb_pull(skb
, skb_network_header_len(skb
));
1486 if (opt
&& opt
->opt_flen
)
1487 ipv6_push_frag_opts(skb
, opt
, &proto
);
1488 if (opt
&& opt
->opt_nflen
)
1489 ipv6_push_nfrag_opts(skb
, opt
, &proto
, &final_dst
);
1491 skb_push(skb
, sizeof(struct ipv6hdr
));
1492 skb_reset_network_header(skb
);
1493 hdr
= ipv6_hdr(skb
);
1495 *(__be32
*)hdr
= fl
->fl6_flowlabel
|
1496 htonl(0x60000000 | ((int)np
->cork
.tclass
<< 20));
1498 hdr
->hop_limit
= np
->cork
.hop_limit
;
1499 hdr
->nexthdr
= proto
;
1500 ipv6_addr_copy(&hdr
->saddr
, &fl
->fl6_src
);
1501 ipv6_addr_copy(&hdr
->daddr
, final_dst
);
1503 skb
->priority
= sk
->sk_priority
;
1504 skb
->mark
= sk
->sk_mark
;
1506 skb_dst_set(skb
, dst_clone(&rt
->dst
));
1507 IP6_UPD_PO_STATS(net
, rt
->rt6i_idev
, IPSTATS_MIB_OUT
, skb
->len
);
1508 if (proto
== IPPROTO_ICMPV6
) {
1509 struct inet6_dev
*idev
= ip6_dst_idev(skb_dst(skb
));
1511 ICMP6MSGOUT_INC_STATS_BH(net
, idev
, icmp6_hdr(skb
)->icmp6_type
);
1512 ICMP6_INC_STATS_BH(net
, idev
, ICMP6_MIB_OUTMSGS
);
1515 err
= ip6_local_out(skb
);
1518 err
= net_xmit_errno(err
);
1524 ip6_cork_release(inet
, np
);
1527 IP6_INC_STATS(net
, rt
->rt6i_idev
, IPSTATS_MIB_OUTDISCARDS
);
1531 void ip6_flush_pending_frames(struct sock
*sk
)
1533 struct sk_buff
*skb
;
1535 while ((skb
= __skb_dequeue_tail(&sk
->sk_write_queue
)) != NULL
) {
1537 IP6_INC_STATS(sock_net(sk
), ip6_dst_idev(skb_dst(skb
)),
1538 IPSTATS_MIB_OUTDISCARDS
);
1542 ip6_cork_release(inet_sk(sk
), inet6_sk(sk
));