2 * IPv6 output functions
3 * Linux INET6 implementation
6 * Pedro Roque <roque@di.fc.ul.pt>
8 * $Id: ip6_output.c,v 1.34 2002/02/01 22:01:04 davem Exp $
10 * Based on linux/net/ipv4/ip_output.c
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
18 * A.N.Kuznetsov : airthmetics in fragmentation.
19 * extension headers are implemented.
20 * route changes now work.
21 * ip6_forward does not confuse sniffers.
24 * H. von Brand : Added missing #include <linux/string.h>
25 * Imran Patel : frag id should be in NBO
26 * Kazunori MIYAZAWA @USAGI
27 * : add ip6_append_data and related functions
31 #include <linux/errno.h>
32 #include <linux/types.h>
33 #include <linux/string.h>
34 #include <linux/socket.h>
35 #include <linux/net.h>
36 #include <linux/netdevice.h>
37 #include <linux/if_arp.h>
38 #include <linux/in6.h>
39 #include <linux/tcp.h>
40 #include <linux/route.h>
41 #include <linux/module.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>
59 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
61 static __inline__ void ipv6_select_ident(struct sk_buff *skb, struct frag_hdr *fhdr)
63 static u32 ipv6_fragmentation_id = 1;
64 static DEFINE_SPINLOCK(ip6_id_lock);
66 spin_lock_bh(&ip6_id_lock);
67 fhdr->identification = htonl(ipv6_fragmentation_id);
68 if (++ipv6_fragmentation_id == 0)
69 ipv6_fragmentation_id = 1;
70 spin_unlock_bh(&ip6_id_lock);
73 static inline int ip6_output_finish(struct sk_buff *skb)
76 struct dst_entry *dst = skb->dst;
77 struct hh_cache *hh = dst->hh;
82 read_lock_bh(&hh->hh_lock);
83 hh_alen = HH_DATA_ALIGN(hh->hh_len);
84 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
85 read_unlock_bh(&hh->hh_lock);
86 skb_push(skb, hh->hh_len);
87 return hh->hh_output(skb);
88 } else if (dst->neighbour)
89 return dst->neighbour->output(skb);
91 IP6_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
97 /* dev_loopback_xmit for use with netfilter. */
98 static int ip6_dev_loopback_xmit(struct sk_buff *newskb)
100 newskb->mac.raw = newskb->data;
101 __skb_pull(newskb, newskb->nh.raw - newskb->data);
102 newskb->pkt_type = PACKET_LOOPBACK;
103 newskb->ip_summed = CHECKSUM_UNNECESSARY;
104 BUG_TRAP(newskb->dst);
111 static int ip6_output2(struct sk_buff *skb)
113 struct dst_entry *dst = skb->dst;
114 struct net_device *dev = dst->dev;
116 skb->protocol = htons(ETH_P_IPV6);
119 if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr)) {
120 struct ipv6_pinfo* np = skb->sk ? inet6_sk(skb->sk) : NULL;
122 if (!(dev->flags & IFF_LOOPBACK) && (!np || np->mc_loop) &&
123 ipv6_chk_mcast_addr(dev, &skb->nh.ipv6h->daddr,
124 &skb->nh.ipv6h->saddr)) {
125 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
127 /* Do not check for IFF_ALLMULTI; multicast routing
128 is not supported in any case.
131 NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, newskb, NULL,
133 ip6_dev_loopback_xmit);
135 if (skb->nh.ipv6h->hop_limit == 0) {
136 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
142 IP6_INC_STATS(IPSTATS_MIB_OUTMCASTPKTS);
145 return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb,NULL, skb->dev,ip6_output_finish);
148 int ip6_output(struct sk_buff *skb)
150 if ((skb->len > dst_mtu(skb->dst) && !skb_is_gso(skb)) ||
151 dst_allfrag(skb->dst))
152 return ip6_fragment(skb, ip6_output2);
154 return ip6_output2(skb);
158 * xmit an sk_buff (used by TCP)
161 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
162 struct ipv6_txoptions *opt, int ipfragok)
164 struct ipv6_pinfo *np = inet6_sk(sk);
165 struct in6_addr *first_hop = &fl->fl6_dst;
166 struct dst_entry *dst = skb->dst;
168 u8 proto = fl->proto;
169 int seg_len = skb->len;
176 /* First: exthdrs may take lots of space (~8K for now)
177 MAX_HEADER is not enough.
179 head_room = opt->opt_nflen + opt->opt_flen;
180 seg_len += head_room;
181 head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
183 if (skb_headroom(skb) < head_room) {
184 struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
188 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
192 skb_set_owner_w(skb, sk);
195 ipv6_push_frag_opts(skb, opt, &proto);
197 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
200 hdr = skb->nh.ipv6h = (struct ipv6hdr*)skb_push(skb, sizeof(struct ipv6hdr));
203 * Fill in the IPv6 header
208 hlimit = np->hop_limit;
210 hlimit = dst_metric(dst, RTAX_HOPLIMIT);
212 hlimit = ipv6_get_hoplimit(dst->dev);
220 *(u32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl->fl6_flowlabel;
222 hdr->payload_len = htons(seg_len);
223 hdr->nexthdr = proto;
224 hdr->hop_limit = hlimit;
226 ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
227 ipv6_addr_copy(&hdr->daddr, first_hop);
229 skb->priority = sk->sk_priority;
232 if ((skb->len <= mtu) || ipfragok || skb_is_gso(skb)) {
233 IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
234 return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev,
239 printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n");
241 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
242 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
248 * To avoid extra problems ND packets are send through this
249 * routine. It's code duplication but I really want to avoid
250 * extra checks since ipv6_build_header is used by TCP (which
251 * is for us performance critical)
254 int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev,
255 struct in6_addr *saddr, struct in6_addr *daddr,
258 struct ipv6_pinfo *np = inet6_sk(sk);
262 skb->protocol = htons(ETH_P_IPV6);
265 totlen = len + sizeof(struct ipv6hdr);
267 hdr = (struct ipv6hdr *) skb_put(skb, sizeof(struct ipv6hdr));
270 *(u32*)hdr = htonl(0x60000000);
272 hdr->payload_len = htons(len);
273 hdr->nexthdr = proto;
274 hdr->hop_limit = np->hop_limit;
276 ipv6_addr_copy(&hdr->saddr, saddr);
277 ipv6_addr_copy(&hdr->daddr, daddr);
282 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
284 struct ip6_ra_chain *ra;
285 struct sock *last = NULL;
287 read_lock(&ip6_ra_lock);
288 for (ra = ip6_ra_chain; ra; ra = ra->next) {
289 struct sock *sk = ra->sk;
290 if (sk && ra->sel == sel &&
291 (!sk->sk_bound_dev_if ||
292 sk->sk_bound_dev_if == skb->dev->ifindex)) {
294 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
296 rawv6_rcv(last, skb2);
303 rawv6_rcv(last, skb);
304 read_unlock(&ip6_ra_lock);
307 read_unlock(&ip6_ra_lock);
311 static inline int ip6_forward_finish(struct sk_buff *skb)
313 return dst_output(skb);
316 int ip6_forward(struct sk_buff *skb)
318 struct dst_entry *dst = skb->dst;
319 struct ipv6hdr *hdr = skb->nh.ipv6h;
320 struct inet6_skb_parm *opt = IP6CB(skb);
322 if (ipv6_devconf.forwarding == 0)
325 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
326 IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
330 skb->ip_summed = CHECKSUM_NONE;
333 * We DO NOT make any processing on
334 * RA packets, pushing them to user level AS IS
335 * without ane WARRANTY that application will be able
336 * to interpret them. The reason is that we
337 * cannot make anything clever here.
339 * We are not end-node, so that if packet contains
340 * AH/ESP, we cannot make anything.
341 * Defragmentation also would be mistake, RA packets
342 * cannot be fragmented, because there is no warranty
343 * that different fragments will go along one path. --ANK
346 u8 *ptr = skb->nh.raw + opt->ra;
347 if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
352 * check and decrement ttl
354 if (hdr->hop_limit <= 1) {
355 /* Force OUTPUT device used as source address */
357 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
359 IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
365 if (!xfrm6_route_forward(skb)) {
366 IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
371 /* IPv6 specs say nothing about it, but it is clear that we cannot
372 send redirects to source routed frames.
374 if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0) {
375 struct in6_addr *target = NULL;
377 struct neighbour *n = dst->neighbour;
380 * incoming and outgoing devices are the same
384 rt = (struct rt6_info *) dst;
385 if ((rt->rt6i_flags & RTF_GATEWAY))
386 target = (struct in6_addr*)&n->primary_key;
388 target = &hdr->daddr;
390 /* Limit redirects both by destination (here)
391 and by source (inside ndisc_send_redirect)
393 if (xrlim_allow(dst, 1*HZ))
394 ndisc_send_redirect(skb, n, target);
395 } else if (ipv6_addr_type(&hdr->saddr)&(IPV6_ADDR_MULTICAST|IPV6_ADDR_LOOPBACK
396 |IPV6_ADDR_LINKLOCAL)) {
397 /* This check is security critical. */
401 if (skb->len > dst_mtu(dst)) {
402 /* Again, force OUTPUT device used as source address */
404 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, dst_mtu(dst), skb->dev);
405 IP6_INC_STATS_BH(IPSTATS_MIB_INTOOBIGERRORS);
406 IP6_INC_STATS_BH(IPSTATS_MIB_FRAGFAILS);
411 if (skb_cow(skb, dst->dev->hard_header_len)) {
412 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
418 /* Mangling hops number delayed to point after skb COW */
422 IP6_INC_STATS_BH(IPSTATS_MIB_OUTFORWDATAGRAMS);
423 return NF_HOOK(PF_INET6,NF_IP6_FORWARD, skb, skb->dev, dst->dev, ip6_forward_finish);
426 IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
432 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
434 to->pkt_type = from->pkt_type;
435 to->priority = from->priority;
436 to->protocol = from->protocol;
437 dst_release(to->dst);
438 to->dst = dst_clone(from->dst);
441 #ifdef CONFIG_NET_SCHED
442 to->tc_index = from->tc_index;
444 #ifdef CONFIG_NETFILTER
445 to->nfmark = from->nfmark;
446 /* Connection association is same as pre-frag packet */
447 nf_conntrack_put(to->nfct);
448 to->nfct = from->nfct;
449 nf_conntrack_get(to->nfct);
450 to->nfctinfo = from->nfctinfo;
451 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
452 nf_conntrack_put_reasm(to->nfct_reasm);
453 to->nfct_reasm = from->nfct_reasm;
454 nf_conntrack_get_reasm(to->nfct_reasm);
456 #ifdef CONFIG_BRIDGE_NETFILTER
457 nf_bridge_put(to->nf_bridge);
458 to->nf_bridge = from->nf_bridge;
459 nf_bridge_get(to->nf_bridge);
462 skb_copy_secmark(to, from);
465 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
467 u16 offset = sizeof(struct ipv6hdr);
468 struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.ipv6h + 1);
469 unsigned int packet_len = skb->tail - skb->nh.raw;
471 *nexthdr = &skb->nh.ipv6h->nexthdr;
473 while (offset + 1 <= packet_len) {
478 case NEXTHDR_ROUTING:
480 if (**nexthdr == NEXTHDR_ROUTING) found_rhdr = 1;
481 if (**nexthdr == NEXTHDR_DEST && found_rhdr) return offset;
482 offset += ipv6_optlen(exthdr);
483 *nexthdr = &exthdr->nexthdr;
484 exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
493 EXPORT_SYMBOL_GPL(ip6_find_1stfragopt);
495 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
497 struct net_device *dev;
498 struct sk_buff *frag;
499 struct rt6_info *rt = (struct rt6_info*)skb->dst;
500 struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
501 struct ipv6hdr *tmp_hdr;
503 unsigned int mtu, hlen, left, len;
505 int ptr, offset = 0, err=0;
506 u8 *prevhdr, nexthdr = 0;
509 hlen = ip6_find_1stfragopt(skb, &prevhdr);
512 mtu = dst_mtu(&rt->u.dst);
513 if (np && np->frag_size < mtu) {
517 mtu -= hlen + sizeof(struct frag_hdr);
519 if (skb_shinfo(skb)->frag_list) {
520 int first_len = skb_pagelen(skb);
522 if (first_len - hlen > mtu ||
523 ((first_len - hlen) & 7) ||
527 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
528 /* Correct geometry. */
529 if (frag->len > mtu ||
530 ((frag->len & 7) && frag->next) ||
531 skb_headroom(frag) < hlen)
534 /* Partially cloned skb? */
535 if (skb_shared(frag))
542 frag->destructor = sock_wfree;
543 skb->truesize -= frag->truesize;
549 frag = skb_shinfo(skb)->frag_list;
550 skb_shinfo(skb)->frag_list = NULL;
553 tmp_hdr = kmalloc(hlen, GFP_ATOMIC);
555 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
559 *prevhdr = NEXTHDR_FRAGMENT;
560 memcpy(tmp_hdr, skb->nh.raw, hlen);
561 __skb_pull(skb, hlen);
562 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
563 skb->nh.raw = __skb_push(skb, hlen);
564 memcpy(skb->nh.raw, tmp_hdr, hlen);
566 ipv6_select_ident(skb, fh);
567 fh->nexthdr = nexthdr;
569 fh->frag_off = htons(IP6_MF);
570 frag_id = fh->identification;
572 first_len = skb_pagelen(skb);
573 skb->data_len = first_len - skb_headlen(skb);
574 skb->len = first_len;
575 skb->nh.ipv6h->payload_len = htons(first_len - sizeof(struct ipv6hdr));
579 /* Prepare header of the next frame,
580 * before previous one went down. */
582 frag->ip_summed = CHECKSUM_NONE;
583 frag->h.raw = frag->data;
584 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
585 frag->nh.raw = __skb_push(frag, hlen);
586 memcpy(frag->nh.raw, tmp_hdr, hlen);
587 offset += skb->len - hlen - sizeof(struct frag_hdr);
588 fh->nexthdr = nexthdr;
590 fh->frag_off = htons(offset);
591 if (frag->next != NULL)
592 fh->frag_off |= htons(IP6_MF);
593 fh->identification = frag_id;
594 frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
595 ip6_copy_metadata(frag, skb);
600 IP6_INC_STATS(IPSTATS_MIB_FRAGCREATES);
613 IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
623 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
628 left = skb->len - hlen; /* Space per frame */
629 ptr = hlen; /* Where to start from */
632 * Fragment the datagram.
635 *prevhdr = NEXTHDR_FRAGMENT;
638 * Keep copying data until we run out.
642 /* IF: it doesn't fit, use 'mtu' - the data space left */
645 /* IF: we are not sending upto and including the packet end
646 then align the next start on an eight byte boundary */
654 if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) {
655 NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
656 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
662 * Set up data on packet
665 ip6_copy_metadata(frag, skb);
666 skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev));
667 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
668 frag->nh.raw = frag->data;
669 fh = (struct frag_hdr*)(frag->data + hlen);
670 frag->h.raw = frag->data + hlen + sizeof(struct frag_hdr);
673 * Charge the memory for the fragment to any owner
677 skb_set_owner_w(frag, skb->sk);
680 * Copy the packet header into the new buffer.
682 memcpy(frag->nh.raw, skb->data, hlen);
685 * Build fragment header.
687 fh->nexthdr = nexthdr;
690 ipv6_select_ident(skb, fh);
691 frag_id = fh->identification;
693 fh->identification = frag_id;
696 * Copy a block of the IP datagram.
698 if (skb_copy_bits(skb, ptr, frag->h.raw, len))
702 fh->frag_off = htons(offset);
704 fh->frag_off |= htons(IP6_MF);
705 frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
711 * Put this fragment into the sending queue.
717 IP6_INC_STATS(IPSTATS_MIB_FRAGCREATES);
720 IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
725 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
729 static inline int ip6_rt_check(struct rt6key *rt_key,
730 struct in6_addr *fl_addr,
731 struct in6_addr *addr_cache)
733 return ((rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
734 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache)));
737 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
738 struct dst_entry *dst,
741 struct ipv6_pinfo *np = inet6_sk(sk);
742 struct rt6_info *rt = (struct rt6_info *)dst;
747 /* Yes, checking route validity in not connected
748 * case is not very simple. Take into account,
749 * that we do not support routing by source, TOS,
750 * and MSG_DONTROUTE --ANK (980726)
752 * 1. ip6_rt_check(): If route was host route,
753 * check that cached destination is current.
754 * If it is network route, we still may
755 * check its validity using saved pointer
756 * to the last used address: daddr_cache.
757 * We do not want to save whole address now,
758 * (because main consumer of this service
759 * is tcp, which has not this problem),
760 * so that the last trick works only on connected
762 * 2. oif also should be the same.
764 if (ip6_rt_check(&rt->rt6i_dst, &fl->fl6_dst, np->daddr_cache) ||
765 #ifdef CONFIG_IPV6_SUBTREES
766 ip6_rt_check(&rt->rt6i_src, &fl->fl6_src, np->saddr_cache) ||
768 (fl->oif && fl->oif != dst->dev->ifindex)) {
777 static int ip6_dst_lookup_tail(struct sock *sk,
778 struct dst_entry **dst, struct flowi *fl)
783 *dst = ip6_route_output(sk, fl);
785 if ((err = (*dst)->error))
786 goto out_err_release;
788 if (ipv6_addr_any(&fl->fl6_src)) {
789 err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src);
791 goto out_err_release;
803 * ip6_dst_lookup - perform route lookup on flow
804 * @sk: socket which provides route info
805 * @dst: pointer to dst_entry * for result
806 * @fl: flow to lookup
808 * This function performs a route lookup on the given flow.
810 * It returns zero on success, or a standard errno code on error.
812 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
815 return ip6_dst_lookup_tail(sk, dst, fl);
817 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
820 * ip6_sk_dst_lookup - perform socket cached route lookup on flow
821 * @sk: socket which provides the dst cache and route info
822 * @dst: pointer to dst_entry * for result
823 * @fl: flow to lookup
825 * This function performs a route lookup on the given flow with the
826 * possibility of using the cached route in the socket if it is valid.
827 * It will take the socket dst lock when operating on the dst cache.
828 * As a result, this function can only be used in process context.
830 * It returns zero on success, or a standard errno code on error.
832 int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
836 *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
837 *dst = ip6_sk_dst_check(sk, *dst, fl);
840 return ip6_dst_lookup_tail(sk, dst, fl);
842 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup);
844 static inline int ip6_ufo_append_data(struct sock *sk,
845 int getfrag(void *from, char *to, int offset, int len,
846 int odd, struct sk_buff *skb),
847 void *from, int length, int hh_len, int fragheaderlen,
848 int transhdrlen, int mtu,unsigned int flags)
854 /* There is support for UDP large send offload by network
855 * device, so create one single skb packet containing complete
858 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
859 skb = sock_alloc_send_skb(sk,
860 hh_len + fragheaderlen + transhdrlen + 20,
861 (flags & MSG_DONTWAIT), &err);
865 /* reserve space for Hardware header */
866 skb_reserve(skb, hh_len);
868 /* create space for UDP/IP header */
869 skb_put(skb,fragheaderlen + transhdrlen);
871 /* initialize network header pointer */
872 skb->nh.raw = skb->data;
874 /* initialize protocol header pointer */
875 skb->h.raw = skb->data + fragheaderlen;
877 skb->ip_summed = CHECKSUM_PARTIAL;
879 sk->sk_sndmsg_off = 0;
882 err = skb_append_datato_frags(sk,skb, getfrag, from,
883 (length - transhdrlen));
885 struct frag_hdr fhdr;
887 /* specify the length of each IP datagram fragment*/
888 skb_shinfo(skb)->gso_size = mtu - fragheaderlen -
889 sizeof(struct frag_hdr);
890 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
891 ipv6_select_ident(skb, &fhdr);
892 skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
893 __skb_queue_tail(&sk->sk_write_queue, skb);
897 /* There is not enough support do UPD LSO,
898 * so follow normal path
905 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
906 int offset, int len, int odd, struct sk_buff *skb),
907 void *from, int length, int transhdrlen,
908 int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl,
909 struct rt6_info *rt, unsigned int flags)
911 struct inet_sock *inet = inet_sk(sk);
912 struct ipv6_pinfo *np = inet6_sk(sk);
914 unsigned int maxfraglen, fragheaderlen;
921 int csummode = CHECKSUM_NONE;
925 if (skb_queue_empty(&sk->sk_write_queue)) {
930 if (np->cork.opt == NULL) {
931 np->cork.opt = kmalloc(opt->tot_len,
933 if (unlikely(np->cork.opt == NULL))
935 } else if (np->cork.opt->tot_len < opt->tot_len) {
936 printk(KERN_DEBUG "ip6_append_data: invalid option length\n");
939 memcpy(np->cork.opt, opt, opt->tot_len);
940 inet->cork.flags |= IPCORK_OPT;
941 /* need source address above miyazawa*/
943 dst_hold(&rt->u.dst);
946 np->cork.hop_limit = hlimit;
947 np->cork.tclass = tclass;
948 mtu = dst_mtu(rt->u.dst.path);
949 if (np->frag_size < mtu) {
953 inet->cork.fragsize = mtu;
954 if (dst_allfrag(rt->u.dst.path))
955 inet->cork.flags |= IPCORK_ALLFRAG;
956 inet->cork.length = 0;
957 sk->sk_sndmsg_page = NULL;
958 sk->sk_sndmsg_off = 0;
959 exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0);
961 transhdrlen += exthdrlen;
965 if (inet->cork.flags & IPCORK_OPT)
969 mtu = inet->cork.fragsize;
972 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
974 fragheaderlen = sizeof(struct ipv6hdr) + rt->u.dst.nfheader_len + (opt ? opt->opt_nflen : 0);
975 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
977 if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
978 if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
979 ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen);
985 * Let's try using as much space as possible.
986 * Use MTU if total length of the message fits into the MTU.
987 * Otherwise, we need to reserve fragment header and
988 * fragment alignment (= 8-15 octects, in total).
990 * Note that we may need to "move" the data from the tail of
991 * of the buffer to the new fragment when we split
994 * FIXME: It may be fragmented into multiple chunks
995 * at once if non-fragmentable extension headers
1000 inet->cork.length += length;
1001 if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) &&
1002 (rt->u.dst.dev->features & NETIF_F_UFO)) {
1004 err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len,
1005 fragheaderlen, transhdrlen, mtu,
1012 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1015 while (length > 0) {
1016 /* Check if the remaining data fits into current packet. */
1017 copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1019 copy = maxfraglen - skb->len;
1023 unsigned int datalen;
1024 unsigned int fraglen;
1025 unsigned int fraggap;
1026 unsigned int alloclen;
1027 struct sk_buff *skb_prev;
1031 /* There's no room in the current skb */
1033 fraggap = skb_prev->len - maxfraglen;
1038 * If remaining data exceeds the mtu,
1039 * we know we need more fragment(s).
1041 datalen = length + fraggap;
1042 if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1043 datalen = maxfraglen - fragheaderlen;
1045 fraglen = datalen + fragheaderlen;
1046 if ((flags & MSG_MORE) &&
1047 !(rt->u.dst.dev->features&NETIF_F_SG))
1050 alloclen = datalen + fragheaderlen;
1053 * The last fragment gets additional space at tail.
1054 * Note: we overallocate on fragments with MSG_MODE
1055 * because we have no idea if we're the last one.
1057 if (datalen == length + fraggap)
1058 alloclen += rt->u.dst.trailer_len;
1061 * We just reserve space for fragment header.
1062 * Note: this may be overallocation if the message
1063 * (without MSG_MORE) fits into the MTU.
1065 alloclen += sizeof(struct frag_hdr);
1068 skb = sock_alloc_send_skb(sk,
1070 (flags & MSG_DONTWAIT), &err);
1073 if (atomic_read(&sk->sk_wmem_alloc) <=
1075 skb = sock_wmalloc(sk,
1076 alloclen + hh_len, 1,
1078 if (unlikely(skb == NULL))
1084 * Fill in the control structures
1086 skb->ip_summed = csummode;
1088 /* reserve for fragmentation */
1089 skb_reserve(skb, hh_len+sizeof(struct frag_hdr));
1092 * Find where to start putting bytes
1094 data = skb_put(skb, fraglen);
1095 skb->nh.raw = data + exthdrlen;
1096 data += fragheaderlen;
1097 skb->h.raw = data + exthdrlen;
1100 skb->csum = skb_copy_and_csum_bits(
1101 skb_prev, maxfraglen,
1102 data + transhdrlen, fraggap, 0);
1103 skb_prev->csum = csum_sub(skb_prev->csum,
1106 pskb_trim_unique(skb_prev, maxfraglen);
1108 copy = datalen - transhdrlen - fraggap;
1113 } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1120 length -= datalen - fraggap;
1123 csummode = CHECKSUM_NONE;
1126 * Put the packet on the pending queue
1128 __skb_queue_tail(&sk->sk_write_queue, skb);
1135 if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
1139 if (getfrag(from, skb_put(skb, copy),
1140 offset, copy, off, skb) < 0) {
1141 __skb_trim(skb, off);
1146 int i = skb_shinfo(skb)->nr_frags;
1147 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
1148 struct page *page = sk->sk_sndmsg_page;
1149 int off = sk->sk_sndmsg_off;
1152 if (page && (left = PAGE_SIZE - off) > 0) {
1155 if (page != frag->page) {
1156 if (i == MAX_SKB_FRAGS) {
1161 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
1162 frag = &skb_shinfo(skb)->frags[i];
1164 } else if(i < MAX_SKB_FRAGS) {
1165 if (copy > PAGE_SIZE)
1167 page = alloc_pages(sk->sk_allocation, 0);
1172 sk->sk_sndmsg_page = page;
1173 sk->sk_sndmsg_off = 0;
1175 skb_fill_page_desc(skb, i, page, 0, 0);
1176 frag = &skb_shinfo(skb)->frags[i];
1177 skb->truesize += PAGE_SIZE;
1178 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
1183 if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
1187 sk->sk_sndmsg_off += copy;
1190 skb->data_len += copy;
1197 inet->cork.length -= length;
1198 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1202 int ip6_push_pending_frames(struct sock *sk)
1204 struct sk_buff *skb, *tmp_skb;
1205 struct sk_buff **tail_skb;
1206 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1207 struct inet_sock *inet = inet_sk(sk);
1208 struct ipv6_pinfo *np = inet6_sk(sk);
1209 struct ipv6hdr *hdr;
1210 struct ipv6_txoptions *opt = np->cork.opt;
1211 struct rt6_info *rt = np->cork.rt;
1212 struct flowi *fl = &inet->cork.fl;
1213 unsigned char proto = fl->proto;
1216 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1218 tail_skb = &(skb_shinfo(skb)->frag_list);
1220 /* move skb->data to ip header from ext header */
1221 if (skb->data < skb->nh.raw)
1222 __skb_pull(skb, skb->nh.raw - skb->data);
1223 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1224 __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
1225 *tail_skb = tmp_skb;
1226 tail_skb = &(tmp_skb->next);
1227 skb->len += tmp_skb->len;
1228 skb->data_len += tmp_skb->len;
1229 skb->truesize += tmp_skb->truesize;
1230 __sock_put(tmp_skb->sk);
1231 tmp_skb->destructor = NULL;
1235 ipv6_addr_copy(final_dst, &fl->fl6_dst);
1236 __skb_pull(skb, skb->h.raw - skb->nh.raw);
1237 if (opt && opt->opt_flen)
1238 ipv6_push_frag_opts(skb, opt, &proto);
1239 if (opt && opt->opt_nflen)
1240 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1242 skb->nh.ipv6h = hdr = (struct ipv6hdr*) skb_push(skb, sizeof(struct ipv6hdr));
1244 *(u32*)hdr = fl->fl6_flowlabel |
1245 htonl(0x60000000 | ((int)np->cork.tclass << 20));
1247 if (skb->len <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN)
1248 hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
1250 hdr->payload_len = 0;
1251 hdr->hop_limit = np->cork.hop_limit;
1252 hdr->nexthdr = proto;
1253 ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
1254 ipv6_addr_copy(&hdr->daddr, final_dst);
1256 skb->priority = sk->sk_priority;
1258 skb->dst = dst_clone(&rt->u.dst);
1259 IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
1260 err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output);
1263 err = np->recverr ? net_xmit_errno(err) : 0;
1269 inet->cork.flags &= ~IPCORK_OPT;
1270 kfree(np->cork.opt);
1271 np->cork.opt = NULL;
1273 dst_release(&np->cork.rt->u.dst);
1275 inet->cork.flags &= ~IPCORK_ALLFRAG;
1277 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1283 void ip6_flush_pending_frames(struct sock *sk)
1285 struct inet_sock *inet = inet_sk(sk);
1286 struct ipv6_pinfo *np = inet6_sk(sk);
1287 struct sk_buff *skb;
1289 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
1290 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1294 inet->cork.flags &= ~IPCORK_OPT;
1296 kfree(np->cork.opt);
1297 np->cork.opt = NULL;
1299 dst_release(&np->cork.rt->u.dst);
1301 inet->cork.flags &= ~IPCORK_ALLFRAG;
1303 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));