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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 02:20:36 +0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 02:20:36 +0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/ipv6/ip6_output.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'net/ipv6/ip6_output.c')
-rw-r--r--net/ipv6/ip6_output.c1197
1 files changed, 1197 insertions, 0 deletions
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
new file mode 100644
index 000000000000..49208ba75094
--- /dev/null
+++ b/net/ipv6/ip6_output.c
@@ -0,0 +1,1197 @@
+/*
+ * IPv6 output functions
+ * Linux INET6 implementation
+ *
+ * Authors:
+ * Pedro Roque <roque@di.fc.ul.pt>
+ *
+ * $Id: ip6_output.c,v 1.34 2002/02/01 22:01:04 davem Exp $
+ *
+ * Based on linux/net/ipv4/ip_output.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Changes:
+ * A.N.Kuznetsov : airthmetics in fragmentation.
+ * extension headers are implemented.
+ * route changes now work.
+ * ip6_forward does not confuse sniffers.
+ * etc.
+ *
+ * H. von Brand : Added missing #include <linux/string.h>
+ * Imran Patel : frag id should be in NBO
+ * Kazunori MIYAZAWA @USAGI
+ * : add ip6_append_data and related functions
+ * for datagram xmit
+ */
+
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/in6.h>
+#include <linux/tcp.h>
+#include <linux/route.h>
+
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv6.h>
+
+#include <net/sock.h>
+#include <net/snmp.h>
+
+#include <net/ipv6.h>
+#include <net/ndisc.h>
+#include <net/protocol.h>
+#include <net/ip6_route.h>
+#include <net/addrconf.h>
+#include <net/rawv6.h>
+#include <net/icmp.h>
+#include <net/xfrm.h>
+#include <net/checksum.h>
+
+static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
+
+static __inline__ void ipv6_select_ident(struct sk_buff *skb, struct frag_hdr *fhdr)
+{
+ static u32 ipv6_fragmentation_id = 1;
+ static DEFINE_SPINLOCK(ip6_id_lock);
+
+ spin_lock_bh(&ip6_id_lock);
+ fhdr->identification = htonl(ipv6_fragmentation_id);
+ if (++ipv6_fragmentation_id == 0)
+ ipv6_fragmentation_id = 1;
+ spin_unlock_bh(&ip6_id_lock);
+}
+
+static inline int ip6_output_finish(struct sk_buff *skb)
+{
+
+ struct dst_entry *dst = skb->dst;
+ struct hh_cache *hh = dst->hh;
+
+ if (hh) {
+ int hh_alen;
+
+ read_lock_bh(&hh->hh_lock);
+ hh_alen = HH_DATA_ALIGN(hh->hh_len);
+ memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
+ read_unlock_bh(&hh->hh_lock);
+ skb_push(skb, hh->hh_len);
+ return hh->hh_output(skb);
+ } else if (dst->neighbour)
+ return dst->neighbour->output(skb);
+
+ IP6_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
+ kfree_skb(skb);
+ return -EINVAL;
+
+}
+
+/* dev_loopback_xmit for use with netfilter. */
+static int ip6_dev_loopback_xmit(struct sk_buff *newskb)
+{
+ newskb->mac.raw = newskb->data;
+ __skb_pull(newskb, newskb->nh.raw - newskb->data);
+ newskb->pkt_type = PACKET_LOOPBACK;
+ newskb->ip_summed = CHECKSUM_UNNECESSARY;
+ BUG_TRAP(newskb->dst);
+
+ netif_rx(newskb);
+ return 0;
+}
+
+
+static int ip6_output2(struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb->dst;
+ struct net_device *dev = dst->dev;
+
+ skb->protocol = htons(ETH_P_IPV6);
+ skb->dev = dev;
+
+ if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr)) {
+ struct ipv6_pinfo* np = skb->sk ? inet6_sk(skb->sk) : NULL;
+
+ if (!(dev->flags & IFF_LOOPBACK) && (!np || np->mc_loop) &&
+ ipv6_chk_mcast_addr(dev, &skb->nh.ipv6h->daddr,
+ &skb->nh.ipv6h->saddr)) {
+ struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
+
+ /* Do not check for IFF_ALLMULTI; multicast routing
+ is not supported in any case.
+ */
+ if (newskb)
+ NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, newskb, NULL,
+ newskb->dev,
+ ip6_dev_loopback_xmit);
+
+ if (skb->nh.ipv6h->hop_limit == 0) {
+ IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
+ kfree_skb(skb);
+ return 0;
+ }
+ }
+
+ IP6_INC_STATS(IPSTATS_MIB_OUTMCASTPKTS);
+ }
+
+ return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb,NULL, skb->dev,ip6_output_finish);
+}
+
+int ip6_output(struct sk_buff *skb)
+{
+ if (skb->len > dst_mtu(skb->dst) || dst_allfrag(skb->dst))
+ return ip6_fragment(skb, ip6_output2);
+ else
+ return ip6_output2(skb);
+}
+
+#ifdef CONFIG_NETFILTER
+int ip6_route_me_harder(struct sk_buff *skb)
+{
+ struct ipv6hdr *iph = skb->nh.ipv6h;
+ struct dst_entry *dst;
+ struct flowi fl = {
+ .oif = skb->sk ? skb->sk->sk_bound_dev_if : 0,
+ .nl_u =
+ { .ip6_u =
+ { .daddr = iph->daddr,
+ .saddr = iph->saddr, } },
+ .proto = iph->nexthdr,
+ };
+
+ dst = ip6_route_output(skb->sk, &fl);
+
+ if (dst->error) {
+ IP6_INC_STATS(IPSTATS_MIB_OUTNOROUTES);
+ LIMIT_NETDEBUG(
+ printk(KERN_DEBUG "ip6_route_me_harder: No more route.\n"));
+ dst_release(dst);
+ return -EINVAL;
+ }
+
+ /* Drop old route. */
+ dst_release(skb->dst);
+
+ skb->dst = dst;
+ return 0;
+}
+#endif
+
+static inline int ip6_maybe_reroute(struct sk_buff *skb)
+{
+#ifdef CONFIG_NETFILTER
+ if (skb->nfcache & NFC_ALTERED){
+ if (ip6_route_me_harder(skb) != 0){
+ kfree_skb(skb);
+ return -EINVAL;
+ }
+ }
+#endif /* CONFIG_NETFILTER */
+ return dst_output(skb);
+}
+
+/*
+ * xmit an sk_buff (used by TCP)
+ */
+
+int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
+ struct ipv6_txoptions *opt, int ipfragok)
+{
+ struct ipv6_pinfo *np = sk ? inet6_sk(sk) : NULL;
+ struct in6_addr *first_hop = &fl->fl6_dst;
+ struct dst_entry *dst = skb->dst;
+ struct ipv6hdr *hdr;
+ u8 proto = fl->proto;
+ int seg_len = skb->len;
+ int hlimit;
+ u32 mtu;
+
+ if (opt) {
+ int head_room;
+
+ /* First: exthdrs may take lots of space (~8K for now)
+ MAX_HEADER is not enough.
+ */
+ head_room = opt->opt_nflen + opt->opt_flen;
+ seg_len += head_room;
+ head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
+
+ if (skb_headroom(skb) < head_room) {
+ struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
+ kfree_skb(skb);
+ skb = skb2;
+ if (skb == NULL) {
+ IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
+ return -ENOBUFS;
+ }
+ if (sk)
+ skb_set_owner_w(skb, sk);
+ }
+ if (opt->opt_flen)
+ ipv6_push_frag_opts(skb, opt, &proto);
+ if (opt->opt_nflen)
+ ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
+ }
+
+ hdr = skb->nh.ipv6h = (struct ipv6hdr*)skb_push(skb, sizeof(struct ipv6hdr));
+
+ /*
+ * Fill in the IPv6 header
+ */
+
+ *(u32*)hdr = htonl(0x60000000) | fl->fl6_flowlabel;
+ hlimit = -1;
+ if (np)
+ hlimit = np->hop_limit;
+ if (hlimit < 0)
+ hlimit = dst_metric(dst, RTAX_HOPLIMIT);
+ if (hlimit < 0)
+ hlimit = ipv6_get_hoplimit(dst->dev);
+
+ hdr->payload_len = htons(seg_len);
+ hdr->nexthdr = proto;
+ hdr->hop_limit = hlimit;
+
+ ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
+ ipv6_addr_copy(&hdr->daddr, first_hop);
+
+ mtu = dst_mtu(dst);
+ if ((skb->len <= mtu) || ipfragok) {
+ IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
+ return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, ip6_maybe_reroute);
+ }
+
+ if (net_ratelimit())
+ printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n");
+ skb->dev = dst->dev;
+ icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
+ IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
+ kfree_skb(skb);
+ return -EMSGSIZE;
+}
+
+/*
+ * To avoid extra problems ND packets are send through this
+ * routine. It's code duplication but I really want to avoid
+ * extra checks since ipv6_build_header is used by TCP (which
+ * is for us performance critical)
+ */
+
+int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev,
+ struct in6_addr *saddr, struct in6_addr *daddr,
+ int proto, int len)
+{
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ struct ipv6hdr *hdr;
+ int totlen;
+
+ skb->protocol = htons(ETH_P_IPV6);
+ skb->dev = dev;
+
+ totlen = len + sizeof(struct ipv6hdr);
+
+ hdr = (struct ipv6hdr *) skb_put(skb, sizeof(struct ipv6hdr));
+ skb->nh.ipv6h = hdr;
+
+ *(u32*)hdr = htonl(0x60000000);
+
+ hdr->payload_len = htons(len);
+ hdr->nexthdr = proto;
+ hdr->hop_limit = np->hop_limit;
+
+ ipv6_addr_copy(&hdr->saddr, saddr);
+ ipv6_addr_copy(&hdr->daddr, daddr);
+
+ return 0;
+}
+
+static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
+{
+ struct ip6_ra_chain *ra;
+ struct sock *last = NULL;
+
+ read_lock(&ip6_ra_lock);
+ for (ra = ip6_ra_chain; ra; ra = ra->next) {
+ struct sock *sk = ra->sk;
+ if (sk && ra->sel == sel) {
+ if (last) {
+ struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
+ if (skb2)
+ rawv6_rcv(last, skb2);
+ }
+ last = sk;
+ }
+ }
+
+ if (last) {
+ rawv6_rcv(last, skb);
+ read_unlock(&ip6_ra_lock);
+ return 1;
+ }
+ read_unlock(&ip6_ra_lock);
+ return 0;
+}
+
+static inline int ip6_forward_finish(struct sk_buff *skb)
+{
+ return dst_output(skb);
+}
+
+int ip6_forward(struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb->dst;
+ struct ipv6hdr *hdr = skb->nh.ipv6h;
+ struct inet6_skb_parm *opt = IP6CB(skb);
+
+ if (ipv6_devconf.forwarding == 0)
+ goto error;
+
+ if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
+ IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
+ goto drop;
+ }
+
+ skb->ip_summed = CHECKSUM_NONE;
+
+ /*
+ * We DO NOT make any processing on
+ * RA packets, pushing them to user level AS IS
+ * without ane WARRANTY that application will be able
+ * to interpret them. The reason is that we
+ * cannot make anything clever here.
+ *
+ * We are not end-node, so that if packet contains
+ * AH/ESP, we cannot make anything.
+ * Defragmentation also would be mistake, RA packets
+ * cannot be fragmented, because there is no warranty
+ * that different fragments will go along one path. --ANK
+ */
+ if (opt->ra) {
+ u8 *ptr = skb->nh.raw + opt->ra;
+ if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
+ return 0;
+ }
+
+ /*
+ * check and decrement ttl
+ */
+ if (hdr->hop_limit <= 1) {
+ /* Force OUTPUT device used as source address */
+ skb->dev = dst->dev;
+ icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
+ 0, skb->dev);
+
+ kfree_skb(skb);
+ return -ETIMEDOUT;
+ }
+
+ if (!xfrm6_route_forward(skb)) {
+ IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
+ goto drop;
+ }
+ dst = skb->dst;
+
+ /* IPv6 specs say nothing about it, but it is clear that we cannot
+ send redirects to source routed frames.
+ */
+ if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0) {
+ struct in6_addr *target = NULL;
+ struct rt6_info *rt;
+ struct neighbour *n = dst->neighbour;
+
+ /*
+ * incoming and outgoing devices are the same
+ * send a redirect.
+ */
+
+ rt = (struct rt6_info *) dst;
+ if ((rt->rt6i_flags & RTF_GATEWAY))
+ target = (struct in6_addr*)&n->primary_key;
+ else
+ target = &hdr->daddr;
+
+ /* Limit redirects both by destination (here)
+ and by source (inside ndisc_send_redirect)
+ */
+ if (xrlim_allow(dst, 1*HZ))
+ ndisc_send_redirect(skb, n, target);
+ } else if (ipv6_addr_type(&hdr->saddr)&(IPV6_ADDR_MULTICAST|IPV6_ADDR_LOOPBACK
+ |IPV6_ADDR_LINKLOCAL)) {
+ /* This check is security critical. */
+ goto error;
+ }
+
+ if (skb->len > dst_mtu(dst)) {
+ /* Again, force OUTPUT device used as source address */
+ skb->dev = dst->dev;
+ icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, dst_mtu(dst), skb->dev);
+ IP6_INC_STATS_BH(IPSTATS_MIB_INTOOBIGERRORS);
+ IP6_INC_STATS_BH(IPSTATS_MIB_FRAGFAILS);
+ kfree_skb(skb);
+ return -EMSGSIZE;
+ }
+
+ if (skb_cow(skb, dst->dev->hard_header_len)) {
+ IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
+ goto drop;
+ }
+
+ hdr = skb->nh.ipv6h;
+
+ /* Mangling hops number delayed to point after skb COW */
+
+ hdr->hop_limit--;
+
+ IP6_INC_STATS_BH(IPSTATS_MIB_OUTFORWDATAGRAMS);
+ return NF_HOOK(PF_INET6,NF_IP6_FORWARD, skb, skb->dev, dst->dev, ip6_forward_finish);
+
+error:
+ IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
+drop:
+ kfree_skb(skb);
+ return -EINVAL;
+}
+
+static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
+{
+ to->pkt_type = from->pkt_type;
+ to->priority = from->priority;
+ to->protocol = from->protocol;
+ to->security = from->security;
+ dst_release(to->dst);
+ to->dst = dst_clone(from->dst);
+ to->dev = from->dev;
+
+#ifdef CONFIG_NET_SCHED
+ to->tc_index = from->tc_index;
+#endif
+#ifdef CONFIG_NETFILTER
+ to->nfmark = from->nfmark;
+ /* Connection association is same as pre-frag packet */
+ to->nfct = from->nfct;
+ nf_conntrack_get(to->nfct);
+ to->nfctinfo = from->nfctinfo;
+#ifdef CONFIG_BRIDGE_NETFILTER
+ nf_bridge_put(to->nf_bridge);
+ to->nf_bridge = from->nf_bridge;
+ nf_bridge_get(to->nf_bridge);
+#endif
+#ifdef CONFIG_NETFILTER_DEBUG
+ to->nf_debug = from->nf_debug;
+#endif
+#endif
+}
+
+int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
+{
+ u16 offset = sizeof(struct ipv6hdr);
+ struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.ipv6h + 1);
+ unsigned int packet_len = skb->tail - skb->nh.raw;
+ int found_rhdr = 0;
+ *nexthdr = &skb->nh.ipv6h->nexthdr;
+
+ while (offset + 1 <= packet_len) {
+
+ switch (**nexthdr) {
+
+ case NEXTHDR_HOP:
+ case NEXTHDR_ROUTING:
+ case NEXTHDR_DEST:
+ if (**nexthdr == NEXTHDR_ROUTING) found_rhdr = 1;
+ if (**nexthdr == NEXTHDR_DEST && found_rhdr) return offset;
+ offset += ipv6_optlen(exthdr);
+ *nexthdr = &exthdr->nexthdr;
+ exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
+ break;
+ default :
+ return offset;
+ }
+ }
+
+ return offset;
+}
+
+static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
+{
+ struct net_device *dev;
+ struct sk_buff *frag;
+ struct rt6_info *rt = (struct rt6_info*)skb->dst;
+ struct ipv6hdr *tmp_hdr;
+ struct frag_hdr *fh;
+ unsigned int mtu, hlen, left, len;
+ u32 frag_id = 0;
+ int ptr, offset = 0, err=0;
+ u8 *prevhdr, nexthdr = 0;
+
+ dev = rt->u.dst.dev;
+ hlen = ip6_find_1stfragopt(skb, &prevhdr);
+ nexthdr = *prevhdr;
+
+ mtu = dst_mtu(&rt->u.dst) - hlen - sizeof(struct frag_hdr);
+
+ if (skb_shinfo(skb)->frag_list) {
+ int first_len = skb_pagelen(skb);
+
+ if (first_len - hlen > mtu ||
+ ((first_len - hlen) & 7) ||
+ skb_cloned(skb))
+ goto slow_path;
+
+ for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
+ /* Correct geometry. */
+ if (frag->len > mtu ||
+ ((frag->len & 7) && frag->next) ||
+ skb_headroom(frag) < hlen)
+ goto slow_path;
+
+ /* Correct socket ownership. */
+ if (frag->sk == NULL)
+ goto slow_path;
+
+ /* Partially cloned skb? */
+ if (skb_shared(frag))
+ goto slow_path;
+ }
+
+ err = 0;
+ offset = 0;
+ frag = skb_shinfo(skb)->frag_list;
+ skb_shinfo(skb)->frag_list = NULL;
+ /* BUILD HEADER */
+
+ tmp_hdr = kmalloc(hlen, GFP_ATOMIC);
+ if (!tmp_hdr) {
+ IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
+ return -ENOMEM;
+ }
+
+ *prevhdr = NEXTHDR_FRAGMENT;
+ memcpy(tmp_hdr, skb->nh.raw, hlen);
+ __skb_pull(skb, hlen);
+ fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
+ skb->nh.raw = __skb_push(skb, hlen);
+ memcpy(skb->nh.raw, tmp_hdr, hlen);
+
+ ipv6_select_ident(skb, fh);
+ fh->nexthdr = nexthdr;
+ fh->reserved = 0;
+ fh->frag_off = htons(IP6_MF);
+ frag_id = fh->identification;
+
+ first_len = skb_pagelen(skb);
+ skb->data_len = first_len - skb_headlen(skb);
+ skb->len = first_len;
+ skb->nh.ipv6h->payload_len = htons(first_len - sizeof(struct ipv6hdr));
+
+
+ for (;;) {
+ /* Prepare header of the next frame,
+ * before previous one went down. */
+ if (frag) {
+ frag->ip_summed = CHECKSUM_NONE;
+ frag->h.raw = frag->data;
+ fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
+ frag->nh.raw = __skb_push(frag, hlen);
+ memcpy(frag->nh.raw, tmp_hdr, hlen);
+ offset += skb->len - hlen - sizeof(struct frag_hdr);
+ fh->nexthdr = nexthdr;
+ fh->reserved = 0;
+ fh->frag_off = htons(offset);
+ if (frag->next != NULL)
+ fh->frag_off |= htons(IP6_MF);
+ fh->identification = frag_id;
+ frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
+ ip6_copy_metadata(frag, skb);
+ }
+
+ err = output(skb);
+ if (err || !frag)
+ break;
+
+ skb = frag;
+ frag = skb->next;
+ skb->next = NULL;
+ }
+
+ if (tmp_hdr)
+ kfree(tmp_hdr);
+
+ if (err == 0) {
+ IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
+ return 0;
+ }
+
+ while (frag) {
+ skb = frag->next;
+ kfree_skb(frag);
+ frag = skb;
+ }
+
+ IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
+ return err;
+ }
+
+slow_path:
+ left = skb->len - hlen; /* Space per frame */
+ ptr = hlen; /* Where to start from */
+
+ /*
+ * Fragment the datagram.
+ */
+
+ *prevhdr = NEXTHDR_FRAGMENT;
+
+ /*
+ * Keep copying data until we run out.
+ */
+ while(left > 0) {
+ len = left;
+ /* IF: it doesn't fit, use 'mtu' - the data space left */
+ if (len > mtu)
+ len = mtu;
+ /* IF: we are not sending upto and including the packet end
+ then align the next start on an eight byte boundary */
+ if (len < left) {
+ len &= ~7;
+ }
+ /*
+ * Allocate buffer.
+ */
+
+ if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) {
+ NETDEBUG(printk(KERN_INFO "IPv6: frag: no memory for new fragment!\n"));
+ IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
+ err = -ENOMEM;
+ goto fail;
+ }
+
+ /*
+ * Set up data on packet
+ */
+
+ ip6_copy_metadata(frag, skb);
+ skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev));
+ skb_put(frag, len + hlen + sizeof(struct frag_hdr));
+ frag->nh.raw = frag->data;
+ fh = (struct frag_hdr*)(frag->data + hlen);
+ frag->h.raw = frag->data + hlen + sizeof(struct frag_hdr);
+
+ /*
+ * Charge the memory for the fragment to any owner
+ * it might possess
+ */
+ if (skb->sk)
+ skb_set_owner_w(frag, skb->sk);
+
+ /*
+ * Copy the packet header into the new buffer.
+ */
+ memcpy(frag->nh.raw, skb->data, hlen);
+
+ /*
+ * Build fragment header.
+ */
+ fh->nexthdr = nexthdr;
+ fh->reserved = 0;
+ if (frag_id) {
+ ipv6_select_ident(skb, fh);
+ frag_id = fh->identification;
+ } else
+ fh->identification = frag_id;
+
+ /*
+ * Copy a block of the IP datagram.
+ */
+ if (skb_copy_bits(skb, ptr, frag->h.raw, len))
+ BUG();
+ left -= len;
+
+ fh->frag_off = htons(offset);
+ if (left > 0)
+ fh->frag_off |= htons(IP6_MF);
+ frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
+
+ ptr += len;
+ offset += len;
+
+ /*
+ * Put this fragment into the sending queue.
+ */
+
+ IP6_INC_STATS(IPSTATS_MIB_FRAGCREATES);
+
+ err = output(frag);
+ if (err)
+ goto fail;
+ }
+ kfree_skb(skb);
+ IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
+ return err;
+
+fail:
+ kfree_skb(skb);
+ IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
+ return err;
+}
+
+int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
+{
+ int err = 0;
+
+ *dst = NULL;
+ if (sk) {
+ struct ipv6_pinfo *np = inet6_sk(sk);
+
+ *dst = sk_dst_check(sk, np->dst_cookie);
+ if (*dst) {
+ struct rt6_info *rt = (struct rt6_info*)*dst;
+
+ /* Yes, checking route validity in not connected
+ case is not very simple. Take into account,
+ that we do not support routing by source, TOS,
+ and MSG_DONTROUTE --ANK (980726)
+
+ 1. If route was host route, check that
+ cached destination is current.
+ If it is network route, we still may
+ check its validity using saved pointer
+ to the last used address: daddr_cache.
+ We do not want to save whole address now,
+ (because main consumer of this service
+ is tcp, which has not this problem),
+ so that the last trick works only on connected
+ sockets.
+ 2. oif also should be the same.
+ */
+
+ if (((rt->rt6i_dst.plen != 128 ||
+ !ipv6_addr_equal(&fl->fl6_dst, &rt->rt6i_dst.addr))
+ && (np->daddr_cache == NULL ||
+ !ipv6_addr_equal(&fl->fl6_dst, np->daddr_cache)))
+ || (fl->oif && fl->oif != (*dst)->dev->ifindex)) {
+ dst_release(*dst);
+ *dst = NULL;
+ }
+ }
+ }
+
+ if (*dst == NULL)
+ *dst = ip6_route_output(sk, fl);
+
+ if ((err = (*dst)->error))
+ goto out_err_release;
+
+ if (ipv6_addr_any(&fl->fl6_src)) {
+ err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src);
+
+ if (err) {
+#if IP6_DEBUG >= 2
+ printk(KERN_DEBUG "ip6_dst_lookup: "
+ "no available source address\n");
+#endif
+ goto out_err_release;
+ }
+ }
+
+ return 0;
+
+out_err_release:
+ dst_release(*dst);
+ *dst = NULL;
+ return err;
+}
+
+int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb),
+ void *from, int length, int transhdrlen,
+ int hlimit, struct ipv6_txoptions *opt, struct flowi *fl, struct rt6_info *rt,
+ unsigned int flags)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ struct sk_buff *skb;
+ unsigned int maxfraglen, fragheaderlen;
+ int exthdrlen;
+ int hh_len;
+ int mtu;
+ int copy;
+ int err;
+ int offset = 0;
+ int csummode = CHECKSUM_NONE;
+
+ if (flags&MSG_PROBE)
+ return 0;
+ if (skb_queue_empty(&sk->sk_write_queue)) {
+ /*
+ * setup for corking
+ */
+ if (opt) {
+ if (np->cork.opt == NULL) {
+ np->cork.opt = kmalloc(opt->tot_len,
+ sk->sk_allocation);
+ if (unlikely(np->cork.opt == NULL))
+ return -ENOBUFS;
+ } else if (np->cork.opt->tot_len < opt->tot_len) {
+ printk(KERN_DEBUG "ip6_append_data: invalid option length\n");
+ return -EINVAL;
+ }
+ memcpy(np->cork.opt, opt, opt->tot_len);
+ inet->cork.flags |= IPCORK_OPT;
+ /* need source address above miyazawa*/
+ }
+ dst_hold(&rt->u.dst);
+ np->cork.rt = rt;
+ inet->cork.fl = *fl;
+ np->cork.hop_limit = hlimit;
+ inet->cork.fragsize = mtu = dst_mtu(rt->u.dst.path);
+ if (dst_allfrag(rt->u.dst.path))
+ inet->cork.flags |= IPCORK_ALLFRAG;
+ inet->cork.length = 0;
+ sk->sk_sndmsg_page = NULL;
+ sk->sk_sndmsg_off = 0;
+ exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0);
+ length += exthdrlen;
+ transhdrlen += exthdrlen;
+ } else {
+ rt = np->cork.rt;
+ fl = &inet->cork.fl;
+ if (inet->cork.flags & IPCORK_OPT)
+ opt = np->cork.opt;
+ transhdrlen = 0;
+ exthdrlen = 0;
+ mtu = inet->cork.fragsize;
+ }
+
+ hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
+
+ fragheaderlen = sizeof(struct ipv6hdr) + (opt ? opt->opt_nflen : 0);
+ maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
+
+ if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
+ if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
+ ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen);
+ return -EMSGSIZE;
+ }
+ }
+
+ /*
+ * Let's try using as much space as possible.
+ * Use MTU if total length of the message fits into the MTU.
+ * Otherwise, we need to reserve fragment header and
+ * fragment alignment (= 8-15 octects, in total).
+ *
+ * Note that we may need to "move" the data from the tail of
+ * of the buffer to the new fragment when we split
+ * the message.
+ *
+ * FIXME: It may be fragmented into multiple chunks
+ * at once if non-fragmentable extension headers
+ * are too large.
+ * --yoshfuji
+ */
+
+ inet->cork.length += length;
+
+ if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
+ goto alloc_new_skb;
+
+ while (length > 0) {
+ /* Check if the remaining data fits into current packet. */
+ copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
+ if (copy < length)
+ copy = maxfraglen - skb->len;
+
+ if (copy <= 0) {
+ char *data;
+ unsigned int datalen;
+ unsigned int fraglen;
+ unsigned int fraggap;
+ unsigned int alloclen;
+ struct sk_buff *skb_prev;
+alloc_new_skb:
+ skb_prev = skb;
+
+ /* There's no room in the current skb */
+ if (skb_prev)
+ fraggap = skb_prev->len - maxfraglen;
+ else
+ fraggap = 0;
+
+ /*
+ * If remaining data exceeds the mtu,
+ * we know we need more fragment(s).
+ */
+ datalen = length + fraggap;
+ if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
+ datalen = maxfraglen - fragheaderlen;
+
+ fraglen = datalen + fragheaderlen;
+ if ((flags & MSG_MORE) &&
+ !(rt->u.dst.dev->features&NETIF_F_SG))
+ alloclen = mtu;
+ else
+ alloclen = datalen + fragheaderlen;
+
+ /*
+ * The last fragment gets additional space at tail.
+ * Note: we overallocate on fragments with MSG_MODE
+ * because we have no idea if we're the last one.
+ */
+ if (datalen == length + fraggap)
+ alloclen += rt->u.dst.trailer_len;
+
+ /*
+ * We just reserve space for fragment header.
+ * Note: this may be overallocation if the message
+ * (without MSG_MORE) fits into the MTU.
+ */
+ alloclen += sizeof(struct frag_hdr);
+
+ if (transhdrlen) {
+ skb = sock_alloc_send_skb(sk,
+ alloclen + hh_len,
+ (flags & MSG_DONTWAIT), &err);
+ } else {
+ skb = NULL;
+ if (atomic_read(&sk->sk_wmem_alloc) <=
+ 2 * sk->sk_sndbuf)
+ skb = sock_wmalloc(sk,
+ alloclen + hh_len, 1,
+ sk->sk_allocation);
+ if (unlikely(skb == NULL))
+ err = -ENOBUFS;
+ }
+ if (skb == NULL)
+ goto error;
+ /*
+ * Fill in the control structures
+ */
+ skb->ip_summed = csummode;
+ skb->csum = 0;
+ /* reserve for fragmentation */
+ skb_reserve(skb, hh_len+sizeof(struct frag_hdr));
+
+ /*
+ * Find where to start putting bytes
+ */
+ data = skb_put(skb, fraglen);
+ skb->nh.raw = data + exthdrlen;
+ data += fragheaderlen;
+ skb->h.raw = data + exthdrlen;
+
+ if (fraggap) {
+ skb->csum = skb_copy_and_csum_bits(
+ skb_prev, maxfraglen,
+ data + transhdrlen, fraggap, 0);
+ skb_prev->csum = csum_sub(skb_prev->csum,
+ skb->csum);
+ data += fraggap;
+ skb_trim(skb_prev, maxfraglen);
+ }
+ copy = datalen - transhdrlen - fraggap;
+ if (copy < 0) {
+ err = -EINVAL;
+ kfree_skb(skb);
+ goto error;
+ } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
+ err = -EFAULT;
+ kfree_skb(skb);
+ goto error;
+ }
+
+ offset += copy;
+ length -= datalen - fraggap;
+ transhdrlen = 0;
+ exthdrlen = 0;
+ csummode = CHECKSUM_NONE;
+
+ /*
+ * Put the packet on the pending queue
+ */
+ __skb_queue_tail(&sk->sk_write_queue, skb);
+ continue;
+ }
+
+ if (copy > length)
+ copy = length;
+
+ if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
+ unsigned int off;
+
+ off = skb->len;
+ if (getfrag(from, skb_put(skb, copy),
+ offset, copy, off, skb) < 0) {
+ __skb_trim(skb, off);
+ err = -EFAULT;
+ goto error;
+ }
+ } else {
+ int i = skb_shinfo(skb)->nr_frags;
+ skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
+ struct page *page = sk->sk_sndmsg_page;
+ int off = sk->sk_sndmsg_off;
+ unsigned int left;
+
+ if (page && (left = PAGE_SIZE - off) > 0) {
+ if (copy >= left)
+ copy = left;
+ if (page != frag->page) {
+ if (i == MAX_SKB_FRAGS) {
+ err = -EMSGSIZE;
+ goto error;
+ }
+ get_page(page);
+ skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
+ frag = &skb_shinfo(skb)->frags[i];
+ }
+ } else if(i < MAX_SKB_FRAGS) {
+ if (copy > PAGE_SIZE)
+ copy = PAGE_SIZE;
+ page = alloc_pages(sk->sk_allocation, 0);
+ if (page == NULL) {
+ err = -ENOMEM;
+ goto error;
+ }
+ sk->sk_sndmsg_page = page;
+ sk->sk_sndmsg_off = 0;
+
+ skb_fill_page_desc(skb, i, page, 0, 0);
+ frag = &skb_shinfo(skb)->frags[i];
+ skb->truesize += PAGE_SIZE;
+ atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
+ } else {
+ err = -EMSGSIZE;
+ goto error;
+ }
+ if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
+ err = -EFAULT;
+ goto error;
+ }
+ sk->sk_sndmsg_off += copy;
+ frag->size += copy;
+ skb->len += copy;
+ skb->data_len += copy;
+ }
+ offset += copy;
+ length -= copy;
+ }
+ return 0;
+error:
+ inet->cork.length -= length;
+ IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
+ return err;
+}
+
+int ip6_push_pending_frames(struct sock *sk)
+{
+ struct sk_buff *skb, *tmp_skb;
+ struct sk_buff **tail_skb;
+ struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
+ struct inet_sock *inet = inet_sk(sk);
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ struct ipv6hdr *hdr;
+ struct ipv6_txoptions *opt = np->cork.opt;
+ struct rt6_info *rt = np->cork.rt;
+ struct flowi *fl = &inet->cork.fl;
+ unsigned char proto = fl->proto;
+ int err = 0;
+
+ if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
+ goto out;
+ tail_skb = &(skb_shinfo(skb)->frag_list);
+
+ /* move skb->data to ip header from ext header */
+ if (skb->data < skb->nh.raw)
+ __skb_pull(skb, skb->nh.raw - skb->data);
+ while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
+ __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
+ *tail_skb = tmp_skb;
+ tail_skb = &(tmp_skb->next);
+ skb->len += tmp_skb->len;
+ skb->data_len += tmp_skb->len;
+#if 0 /* Logically correct, but useless work, ip_fragment() will have to undo */
+ skb->truesize += tmp_skb->truesize;
+ __sock_put(tmp_skb->sk);
+ tmp_skb->destructor = NULL;
+ tmp_skb->sk = NULL;
+#endif
+ }
+
+ ipv6_addr_copy(final_dst, &fl->fl6_dst);
+ __skb_pull(skb, skb->h.raw - skb->nh.raw);
+ if (opt && opt->opt_flen)
+ ipv6_push_frag_opts(skb, opt, &proto);
+ if (opt && opt->opt_nflen)
+ ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
+
+ skb->nh.ipv6h = hdr = (struct ipv6hdr*) skb_push(skb, sizeof(struct ipv6hdr));
+
+ *(u32*)hdr = fl->fl6_flowlabel | htonl(0x60000000);
+
+ if (skb->len <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN)
+ hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
+ else
+ hdr->payload_len = 0;
+ hdr->hop_limit = np->cork.hop_limit;
+ hdr->nexthdr = proto;
+ ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
+ ipv6_addr_copy(&hdr->daddr, final_dst);
+
+ skb->dst = dst_clone(&rt->u.dst);
+ IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
+ err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output);
+ if (err) {
+ if (err > 0)
+ err = inet->recverr ? net_xmit_errno(err) : 0;
+ if (err)
+ goto error;
+ }
+
+out:
+ inet->cork.flags &= ~IPCORK_OPT;
+ if (np->cork.opt) {
+ kfree(np->cork.opt);
+ np->cork.opt = NULL;
+ }
+ if (np->cork.rt) {
+ dst_release(&np->cork.rt->u.dst);
+ np->cork.rt = NULL;
+ inet->cork.flags &= ~IPCORK_ALLFRAG;
+ }
+ memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
+ return err;
+error:
+ goto out;
+}
+
+void ip6_flush_pending_frames(struct sock *sk)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ struct sk_buff *skb;
+
+ while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
+ IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
+ kfree_skb(skb);
+ }
+
+ inet->cork.flags &= ~IPCORK_OPT;
+
+ if (np->cork.opt) {
+ kfree(np->cork.opt);
+ np->cork.opt = NULL;
+ }
+ if (np->cork.rt) {
+ dst_release(&np->cork.rt->u.dst);
+ np->cork.rt = NULL;
+ inet->cork.flags &= ~IPCORK_ALLFRAG;
+ }
+ memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
+}