v4.19.13 snapshot.
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
new file mode 100644
index 0000000..2694def
--- /dev/null
+++ b/net/ipv6/ip6_output.c
@@ -0,0 +1,1784 @@
+/*
+ * IPv6 output functions
+ * Linux INET6 implementation
+ *
+ * Authors:
+ * Pedro Roque <roque@di.fc.ul.pt>
+ *
+ * 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/errno.h>
+#include <linux/kernel.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/module.h>
+#include <linux/slab.h>
+
+#include <linux/bpf-cgroup.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>
+#include <linux/mroute6.h>
+#include <net/l3mdev.h>
+#include <net/lwtunnel.h>
+
+static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb_dst(skb);
+ struct net_device *dev = dst->dev;
+ struct neighbour *neigh;
+ struct in6_addr *nexthop;
+ int ret;
+
+ if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
+ struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
+
+ if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) &&
+ ((mroute6_is_socket(net, skb) &&
+ !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
+ ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
+ &ipv6_hdr(skb)->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(NFPROTO_IPV6, NF_INET_POST_ROUTING,
+ net, sk, newskb, NULL, newskb->dev,
+ dev_loopback_xmit);
+
+ if (ipv6_hdr(skb)->hop_limit == 0) {
+ IP6_INC_STATS(net, idev,
+ IPSTATS_MIB_OUTDISCARDS);
+ kfree_skb(skb);
+ return 0;
+ }
+ }
+
+ IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUTMCAST, skb->len);
+
+ if (IPV6_ADDR_MC_SCOPE(&ipv6_hdr(skb)->daddr) <=
+ IPV6_ADDR_SCOPE_NODELOCAL &&
+ !(dev->flags & IFF_LOOPBACK)) {
+ kfree_skb(skb);
+ return 0;
+ }
+ }
+
+ if (lwtunnel_xmit_redirect(dst->lwtstate)) {
+ int res = lwtunnel_xmit(skb);
+
+ if (res < 0 || res == LWTUNNEL_XMIT_DONE)
+ return res;
+ }
+
+ rcu_read_lock_bh();
+ nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
+ neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
+ if (unlikely(!neigh))
+ neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
+ if (!IS_ERR(neigh)) {
+ sock_confirm_neigh(skb, neigh);
+ ret = neigh_output(neigh, skb);
+ rcu_read_unlock_bh();
+ return ret;
+ }
+ rcu_read_unlock_bh();
+
+ IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
+ kfree_skb(skb);
+ return -EINVAL;
+}
+
+static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+ int ret;
+
+ ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb);
+ if (ret) {
+ kfree_skb(skb);
+ return ret;
+ }
+
+#if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM)
+ /* Policy lookup after SNAT yielded a new policy */
+ if (skb_dst(skb)->xfrm) {
+ IPCB(skb)->flags |= IPSKB_REROUTED;
+ return dst_output(net, sk, skb);
+ }
+#endif
+
+ if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
+ dst_allfrag(skb_dst(skb)) ||
+ (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size))
+ return ip6_fragment(net, sk, skb, ip6_finish_output2);
+ else
+ return ip6_finish_output2(net, sk, skb);
+}
+
+int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+ struct net_device *dev = skb_dst(skb)->dev;
+ struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
+
+ skb->protocol = htons(ETH_P_IPV6);
+ skb->dev = dev;
+
+ if (unlikely(idev->cnf.disable_ipv6)) {
+ IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
+ kfree_skb(skb);
+ return 0;
+ }
+
+ return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
+ net, sk, skb, NULL, dev,
+ ip6_finish_output,
+ !(IP6CB(skb)->flags & IP6SKB_REROUTED));
+}
+
+bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np)
+{
+ if (!np->autoflowlabel_set)
+ return ip6_default_np_autolabel(net);
+ else
+ return np->autoflowlabel;
+}
+
+/*
+ * xmit an sk_buff (used by TCP, SCTP and DCCP)
+ * Note : socket lock is not held for SYNACK packets, but might be modified
+ * by calls to skb_set_owner_w() and ipv6_local_error(),
+ * which are using proper atomic operations or spinlocks.
+ */
+int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
+ __u32 mark, struct ipv6_txoptions *opt, int tclass)
+{
+ struct net *net = sock_net(sk);
+ const struct ipv6_pinfo *np = inet6_sk(sk);
+ struct in6_addr *first_hop = &fl6->daddr;
+ struct dst_entry *dst = skb_dst(skb);
+ unsigned int head_room;
+ struct ipv6hdr *hdr;
+ u8 proto = fl6->flowi6_proto;
+ int seg_len = skb->len;
+ int hlimit = -1;
+ u32 mtu;
+
+ head_room = sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
+ if (opt)
+ head_room += opt->opt_nflen + opt->opt_flen;
+
+ if (unlikely(skb_headroom(skb) < head_room)) {
+ struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
+ if (!skb2) {
+ IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+ IPSTATS_MIB_OUTDISCARDS);
+ kfree_skb(skb);
+ return -ENOBUFS;
+ }
+ if (skb->sk)
+ skb_set_owner_w(skb2, skb->sk);
+ consume_skb(skb);
+ skb = skb2;
+ }
+
+ if (opt) {
+ seg_len += opt->opt_nflen + opt->opt_flen;
+
+ if (opt->opt_flen)
+ ipv6_push_frag_opts(skb, opt, &proto);
+
+ if (opt->opt_nflen)
+ ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop,
+ &fl6->saddr);
+ }
+
+ skb_push(skb, sizeof(struct ipv6hdr));
+ skb_reset_network_header(skb);
+ hdr = ipv6_hdr(skb);
+
+ /*
+ * Fill in the IPv6 header
+ */
+ if (np)
+ hlimit = np->hop_limit;
+ if (hlimit < 0)
+ hlimit = ip6_dst_hoplimit(dst);
+
+ ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel,
+ ip6_autoflowlabel(net, np), fl6));
+
+ hdr->payload_len = htons(seg_len);
+ hdr->nexthdr = proto;
+ hdr->hop_limit = hlimit;
+
+ hdr->saddr = fl6->saddr;
+ hdr->daddr = *first_hop;
+
+ skb->protocol = htons(ETH_P_IPV6);
+ skb->priority = sk->sk_priority;
+ skb->mark = mark;
+
+ mtu = dst_mtu(dst);
+ if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) {
+ IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
+ IPSTATS_MIB_OUT, skb->len);
+
+ /* if egress device is enslaved to an L3 master device pass the
+ * skb to its handler for processing
+ */
+ skb = l3mdev_ip6_out((struct sock *)sk, skb);
+ if (unlikely(!skb))
+ return 0;
+
+ /* hooks should never assume socket lock is held.
+ * we promote our socket to non const
+ */
+ return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
+ net, (struct sock *)sk, skb, NULL, dst->dev,
+ dst_output);
+ }
+
+ skb->dev = dst->dev;
+ /* ipv6_local_error() does not require socket lock,
+ * we promote our socket to non const
+ */
+ ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu);
+
+ IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS);
+ kfree_skb(skb);
+ return -EMSGSIZE;
+}
+EXPORT_SYMBOL(ip6_xmit);
+
+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 &&
+ (!sk->sk_bound_dev_if ||
+ sk->sk_bound_dev_if == skb->dev->ifindex)) {
+ 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 int ip6_forward_proxy_check(struct sk_buff *skb)
+{
+ struct ipv6hdr *hdr = ipv6_hdr(skb);
+ u8 nexthdr = hdr->nexthdr;
+ __be16 frag_off;
+ int offset;
+
+ if (ipv6_ext_hdr(nexthdr)) {
+ offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off);
+ if (offset < 0)
+ return 0;
+ } else
+ offset = sizeof(struct ipv6hdr);
+
+ if (nexthdr == IPPROTO_ICMPV6) {
+ struct icmp6hdr *icmp6;
+
+ if (!pskb_may_pull(skb, (skb_network_header(skb) +
+ offset + 1 - skb->data)))
+ return 0;
+
+ icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
+
+ switch (icmp6->icmp6_type) {
+ case NDISC_ROUTER_SOLICITATION:
+ case NDISC_ROUTER_ADVERTISEMENT:
+ case NDISC_NEIGHBOUR_SOLICITATION:
+ case NDISC_NEIGHBOUR_ADVERTISEMENT:
+ case NDISC_REDIRECT:
+ /* For reaction involving unicast neighbor discovery
+ * message destined to the proxied address, pass it to
+ * input function.
+ */
+ return 1;
+ default:
+ break;
+ }
+ }
+
+ /*
+ * The proxying router can't forward traffic sent to a link-local
+ * address, so signal the sender and discard the packet. This
+ * behavior is clarified by the MIPv6 specification.
+ */
+ if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
+ dst_link_failure(skb);
+ return -1;
+ }
+
+ return 0;
+}
+
+static inline int ip6_forward_finish(struct net *net, struct sock *sk,
+ struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb_dst(skb);
+
+ __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
+ __IP6_ADD_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len);
+
+ return dst_output(net, sk, skb);
+}
+
+static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
+{
+ if (skb->len <= mtu)
+ return false;
+
+ /* ipv6 conntrack defrag sets max_frag_size + ignore_df */
+ if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)
+ return true;
+
+ if (skb->ignore_df)
+ return false;
+
+ if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
+ return false;
+
+ return true;
+}
+
+int ip6_forward(struct sk_buff *skb)
+{
+ struct inet6_dev *idev = __in6_dev_get_safely(skb->dev);
+ struct dst_entry *dst = skb_dst(skb);
+ struct ipv6hdr *hdr = ipv6_hdr(skb);
+ struct inet6_skb_parm *opt = IP6CB(skb);
+ struct net *net = dev_net(dst->dev);
+ u32 mtu;
+
+ if (net->ipv6.devconf_all->forwarding == 0)
+ goto error;
+
+ if (skb->pkt_type != PACKET_HOST)
+ goto drop;
+
+ if (unlikely(skb->sk))
+ goto drop;
+
+ if (skb_warn_if_lro(skb))
+ goto drop;
+
+ if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
+ __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
+ goto drop;
+ }
+
+ skb_forward_csum(skb);
+
+ /*
+ * 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 (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
+ if (ip6_call_ra_chain(skb, ntohs(opt->ra)))
+ 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);
+ __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
+
+ kfree_skb(skb);
+ return -ETIMEDOUT;
+ }
+
+ /* XXX: idev->cnf.proxy_ndp? */
+ if (net->ipv6.devconf_all->proxy_ndp &&
+ pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) {
+ int proxied = ip6_forward_proxy_check(skb);
+ if (proxied > 0)
+ return ip6_input(skb);
+ else if (proxied < 0) {
+ __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
+ goto drop;
+ }
+ }
+
+ if (!xfrm6_route_forward(skb)) {
+ __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
+ goto drop;
+ }
+ dst = skb_dst(skb);
+
+ /* IPv6 specs say nothing about it, but it is clear that we cannot
+ send redirects to source routed frames.
+ We don't send redirects to frames decapsulated from IPsec.
+ */
+ if (IP6CB(skb)->iif == dst->dev->ifindex &&
+ opt->srcrt == 0 && !skb_sec_path(skb)) {
+ struct in6_addr *target = NULL;
+ struct inet_peer *peer;
+ struct rt6_info *rt;
+
+ /*
+ * incoming and outgoing devices are the same
+ * send a redirect.
+ */
+
+ rt = (struct rt6_info *) dst;
+ if (rt->rt6i_flags & RTF_GATEWAY)
+ target = &rt->rt6i_gateway;
+ else
+ target = &hdr->daddr;
+
+ peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1);
+
+ /* Limit redirects both by destination (here)
+ and by source (inside ndisc_send_redirect)
+ */
+ if (inet_peer_xrlim_allow(peer, 1*HZ))
+ ndisc_send_redirect(skb, target);
+ if (peer)
+ inet_putpeer(peer);
+ } else {
+ int addrtype = ipv6_addr_type(&hdr->saddr);
+
+ /* This check is security critical. */
+ if (addrtype == IPV6_ADDR_ANY ||
+ addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK))
+ goto error;
+ if (addrtype & IPV6_ADDR_LINKLOCAL) {
+ icmpv6_send(skb, ICMPV6_DEST_UNREACH,
+ ICMPV6_NOT_NEIGHBOUR, 0);
+ goto error;
+ }
+ }
+
+ mtu = ip6_dst_mtu_forward(dst);
+ if (mtu < IPV6_MIN_MTU)
+ mtu = IPV6_MIN_MTU;
+
+ if (ip6_pkt_too_big(skb, mtu)) {
+ /* Again, force OUTPUT device used as source address */
+ skb->dev = dst->dev;
+ icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+ __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTOOBIGERRORS);
+ __IP6_INC_STATS(net, ip6_dst_idev(dst),
+ IPSTATS_MIB_FRAGFAILS);
+ kfree_skb(skb);
+ return -EMSGSIZE;
+ }
+
+ if (skb_cow(skb, dst->dev->hard_header_len)) {
+ __IP6_INC_STATS(net, ip6_dst_idev(dst),
+ IPSTATS_MIB_OUTDISCARDS);
+ goto drop;
+ }
+
+ hdr = ipv6_hdr(skb);
+
+ /* Mangling hops number delayed to point after skb COW */
+
+ hdr->hop_limit--;
+
+ return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD,
+ net, NULL, skb, skb->dev, dst->dev,
+ ip6_forward_finish);
+
+error:
+ __IP6_INC_STATS(net, idev, 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;
+ skb_dst_drop(to);
+ skb_dst_set(to, dst_clone(skb_dst(from)));
+ to->dev = from->dev;
+ to->mark = from->mark;
+
+ skb_copy_hash(to, from);
+
+#ifdef CONFIG_NET_SCHED
+ to->tc_index = from->tc_index;
+#endif
+ nf_copy(to, from);
+ skb_copy_secmark(to, from);
+}
+
+int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
+ int (*output)(struct net *, struct sock *, struct sk_buff *))
+{
+ struct sk_buff *frag;
+ struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
+ struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
+ inet6_sk(skb->sk) : NULL;
+ struct ipv6hdr *tmp_hdr;
+ struct frag_hdr *fh;
+ unsigned int mtu, hlen, left, len;
+ int hroom, troom;
+ __be32 frag_id;
+ int ptr, offset = 0, err = 0;
+ u8 *prevhdr, nexthdr = 0;
+
+ err = ip6_find_1stfragopt(skb, &prevhdr);
+ if (err < 0)
+ goto fail;
+ hlen = err;
+ nexthdr = *prevhdr;
+
+ mtu = ip6_skb_dst_mtu(skb);
+
+ /* We must not fragment if the socket is set to force MTU discovery
+ * or if the skb it not generated by a local socket.
+ */
+ if (unlikely(!skb->ignore_df && skb->len > mtu))
+ goto fail_toobig;
+
+ if (IP6CB(skb)->frag_max_size) {
+ if (IP6CB(skb)->frag_max_size > mtu)
+ goto fail_toobig;
+
+ /* don't send fragments larger than what we received */
+ mtu = IP6CB(skb)->frag_max_size;
+ if (mtu < IPV6_MIN_MTU)
+ mtu = IPV6_MIN_MTU;
+ }
+
+ if (np && np->frag_size < mtu) {
+ if (np->frag_size)
+ mtu = np->frag_size;
+ }
+ if (mtu < hlen + sizeof(struct frag_hdr) + 8)
+ goto fail_toobig;
+ mtu -= hlen + sizeof(struct frag_hdr);
+
+ frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
+ &ipv6_hdr(skb)->saddr);
+
+ if (skb->ip_summed == CHECKSUM_PARTIAL &&
+ (err = skb_checksum_help(skb)))
+ goto fail;
+
+ hroom = LL_RESERVED_SPACE(rt->dst.dev);
+ if (skb_has_frag_list(skb)) {
+ unsigned int first_len = skb_pagelen(skb);
+ struct sk_buff *frag2;
+
+ if (first_len - hlen > mtu ||
+ ((first_len - hlen) & 7) ||
+ skb_cloned(skb) ||
+ skb_headroom(skb) < (hroom + sizeof(struct frag_hdr)))
+ goto slow_path;
+
+ skb_walk_frags(skb, frag) {
+ /* Correct geometry. */
+ if (frag->len > mtu ||
+ ((frag->len & 7) && frag->next) ||
+ skb_headroom(frag) < (hlen + hroom + sizeof(struct frag_hdr)))
+ goto slow_path_clean;
+
+ /* Partially cloned skb? */
+ if (skb_shared(frag))
+ goto slow_path_clean;
+
+ BUG_ON(frag->sk);
+ if (skb->sk) {
+ frag->sk = skb->sk;
+ frag->destructor = sock_wfree;
+ }
+ skb->truesize -= frag->truesize;
+ }
+
+ err = 0;
+ offset = 0;
+ /* BUILD HEADER */
+
+ *prevhdr = NEXTHDR_FRAGMENT;
+ tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
+ if (!tmp_hdr) {
+ err = -ENOMEM;
+ goto fail;
+ }
+ frag = skb_shinfo(skb)->frag_list;
+ skb_frag_list_init(skb);
+
+ __skb_pull(skb, hlen);
+ fh = __skb_push(skb, sizeof(struct frag_hdr));
+ __skb_push(skb, hlen);
+ skb_reset_network_header(skb);
+ memcpy(skb_network_header(skb), tmp_hdr, hlen);
+
+ fh->nexthdr = nexthdr;
+ fh->reserved = 0;
+ fh->frag_off = htons(IP6_MF);
+ fh->identification = frag_id;
+
+ first_len = skb_pagelen(skb);
+ skb->data_len = first_len - skb_headlen(skb);
+ skb->len = first_len;
+ ipv6_hdr(skb)->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;
+ skb_reset_transport_header(frag);
+ fh = __skb_push(frag, sizeof(struct frag_hdr));
+ __skb_push(frag, hlen);
+ skb_reset_network_header(frag);
+ memcpy(skb_network_header(frag), 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)
+ fh->frag_off |= htons(IP6_MF);
+ fh->identification = frag_id;
+ ipv6_hdr(frag)->payload_len =
+ htons(frag->len -
+ sizeof(struct ipv6hdr));
+ ip6_copy_metadata(frag, skb);
+ }
+
+ err = output(net, sk, skb);
+ if (!err)
+ IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
+ IPSTATS_MIB_FRAGCREATES);
+
+ if (err || !frag)
+ break;
+
+ skb = frag;
+ frag = skb->next;
+ skb->next = NULL;
+ }
+
+ kfree(tmp_hdr);
+
+ if (err == 0) {
+ IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
+ IPSTATS_MIB_FRAGOKS);
+ return 0;
+ }
+
+ kfree_skb_list(frag);
+
+ IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
+ IPSTATS_MIB_FRAGFAILS);
+ return err;
+
+slow_path_clean:
+ skb_walk_frags(skb, frag2) {
+ if (frag2 == frag)
+ break;
+ frag2->sk = NULL;
+ frag2->destructor = NULL;
+ skb->truesize += frag2->truesize;
+ }
+ }
+
+slow_path:
+ left = skb->len - hlen; /* Space per frame */
+ ptr = hlen; /* Where to start from */
+
+ /*
+ * Fragment the datagram.
+ */
+
+ troom = rt->dst.dev->needed_tailroom;
+
+ /*
+ * Keep copying data until we run out.
+ */
+ while (left > 0) {
+ u8 *fragnexthdr_offset;
+
+ len = left;
+ /* IF: it doesn't fit, use 'mtu' - the data space left */
+ if (len > mtu)
+ len = mtu;
+ /* IF: we are not sending up to and including the packet end
+ then align the next start on an eight byte boundary */
+ if (len < left) {
+ len &= ~7;
+ }
+
+ /* Allocate buffer */
+ frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) +
+ hroom + troom, GFP_ATOMIC);
+ if (!frag) {
+ err = -ENOMEM;
+ goto fail;
+ }
+
+ /*
+ * Set up data on packet
+ */
+
+ ip6_copy_metadata(frag, skb);
+ skb_reserve(frag, hroom);
+ skb_put(frag, len + hlen + sizeof(struct frag_hdr));
+ skb_reset_network_header(frag);
+ fh = (struct frag_hdr *)(skb_network_header(frag) + hlen);
+ frag->transport_header = (frag->network_header + 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.
+ */
+ skb_copy_from_linear_data(skb, skb_network_header(frag), hlen);
+
+ fragnexthdr_offset = skb_network_header(frag);
+ fragnexthdr_offset += prevhdr - skb_network_header(skb);
+ *fragnexthdr_offset = NEXTHDR_FRAGMENT;
+
+ /*
+ * Build fragment header.
+ */
+ fh->nexthdr = nexthdr;
+ fh->reserved = 0;
+ fh->identification = frag_id;
+
+ /*
+ * Copy a block of the IP datagram.
+ */
+ BUG_ON(skb_copy_bits(skb, ptr, skb_transport_header(frag),
+ len));
+ left -= len;
+
+ fh->frag_off = htons(offset);
+ if (left > 0)
+ fh->frag_off |= htons(IP6_MF);
+ ipv6_hdr(frag)->payload_len = htons(frag->len -
+ sizeof(struct ipv6hdr));
+
+ ptr += len;
+ offset += len;
+
+ /*
+ * Put this fragment into the sending queue.
+ */
+ err = output(net, sk, frag);
+ if (err)
+ goto fail;
+
+ IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+ IPSTATS_MIB_FRAGCREATES);
+ }
+ IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+ IPSTATS_MIB_FRAGOKS);
+ consume_skb(skb);
+ return err;
+
+fail_toobig:
+ if (skb->sk && dst_allfrag(skb_dst(skb)))
+ sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK);
+
+ icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+ err = -EMSGSIZE;
+
+fail:
+ IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+ IPSTATS_MIB_FRAGFAILS);
+ kfree_skb(skb);
+ return err;
+}
+
+static inline int ip6_rt_check(const struct rt6key *rt_key,
+ const struct in6_addr *fl_addr,
+ const struct in6_addr *addr_cache)
+{
+ return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
+ (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache));
+}
+
+static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
+ struct dst_entry *dst,
+ const struct flowi6 *fl6)
+{
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ struct rt6_info *rt;
+
+ if (!dst)
+ goto out;
+
+ if (dst->ops->family != AF_INET6) {
+ dst_release(dst);
+ return NULL;
+ }
+
+ 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. ip6_rt_check(): 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 (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) ||
+#ifdef CONFIG_IPV6_SUBTREES
+ ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) ||
+#endif
+ (!(fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) &&
+ (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex))) {
+ dst_release(dst);
+ dst = NULL;
+ }
+
+out:
+ return dst;
+}
+
+static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk,
+ struct dst_entry **dst, struct flowi6 *fl6)
+{
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ struct neighbour *n;
+ struct rt6_info *rt;
+#endif
+ int err;
+ int flags = 0;
+
+ /* The correct way to handle this would be to do
+ * ip6_route_get_saddr, and then ip6_route_output; however,
+ * the route-specific preferred source forces the
+ * ip6_route_output call _before_ ip6_route_get_saddr.
+ *
+ * In source specific routing (no src=any default route),
+ * ip6_route_output will fail given src=any saddr, though, so
+ * that's why we try it again later.
+ */
+ if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) {
+ struct fib6_info *from;
+ struct rt6_info *rt;
+ bool had_dst = *dst != NULL;
+
+ if (!had_dst)
+ *dst = ip6_route_output(net, sk, fl6);
+ rt = (*dst)->error ? NULL : (struct rt6_info *)*dst;
+
+ rcu_read_lock();
+ from = rt ? rcu_dereference(rt->from) : NULL;
+ err = ip6_route_get_saddr(net, from, &fl6->daddr,
+ sk ? inet6_sk(sk)->srcprefs : 0,
+ &fl6->saddr);
+ rcu_read_unlock();
+
+ if (err)
+ goto out_err_release;
+
+ /* If we had an erroneous initial result, pretend it
+ * never existed and let the SA-enabled version take
+ * over.
+ */
+ if (!had_dst && (*dst)->error) {
+ dst_release(*dst);
+ *dst = NULL;
+ }
+
+ if (fl6->flowi6_oif)
+ flags |= RT6_LOOKUP_F_IFACE;
+ }
+
+ if (!*dst)
+ *dst = ip6_route_output_flags(net, sk, fl6, flags);
+
+ err = (*dst)->error;
+ if (err)
+ goto out_err_release;
+
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ /*
+ * Here if the dst entry we've looked up
+ * has a neighbour entry that is in the INCOMPLETE
+ * state and the src address from the flow is
+ * marked as OPTIMISTIC, we release the found
+ * dst entry and replace it instead with the
+ * dst entry of the nexthop router
+ */
+ rt = (struct rt6_info *) *dst;
+ rcu_read_lock_bh();
+ n = __ipv6_neigh_lookup_noref(rt->dst.dev,
+ rt6_nexthop(rt, &fl6->daddr));
+ err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0;
+ rcu_read_unlock_bh();
+
+ if (err) {
+ struct inet6_ifaddr *ifp;
+ struct flowi6 fl_gw6;
+ int redirect;
+
+ ifp = ipv6_get_ifaddr(net, &fl6->saddr,
+ (*dst)->dev, 1);
+
+ redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
+ if (ifp)
+ in6_ifa_put(ifp);
+
+ if (redirect) {
+ /*
+ * We need to get the dst entry for the
+ * default router instead
+ */
+ dst_release(*dst);
+ memcpy(&fl_gw6, fl6, sizeof(struct flowi6));
+ memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr));
+ *dst = ip6_route_output(net, sk, &fl_gw6);
+ err = (*dst)->error;
+ if (err)
+ goto out_err_release;
+ }
+ }
+#endif
+ if (ipv6_addr_v4mapped(&fl6->saddr) &&
+ !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) {
+ err = -EAFNOSUPPORT;
+ goto out_err_release;
+ }
+
+ return 0;
+
+out_err_release:
+ dst_release(*dst);
+ *dst = NULL;
+
+ if (err == -ENETUNREACH)
+ IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES);
+ return err;
+}
+
+/**
+ * ip6_dst_lookup - perform route lookup on flow
+ * @sk: socket which provides route info
+ * @dst: pointer to dst_entry * for result
+ * @fl6: flow to lookup
+ *
+ * This function performs a route lookup on the given flow.
+ *
+ * It returns zero on success, or a standard errno code on error.
+ */
+int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
+ struct flowi6 *fl6)
+{
+ *dst = NULL;
+ return ip6_dst_lookup_tail(net, sk, dst, fl6);
+}
+EXPORT_SYMBOL_GPL(ip6_dst_lookup);
+
+/**
+ * ip6_dst_lookup_flow - perform route lookup on flow with ipsec
+ * @sk: socket which provides route info
+ * @fl6: flow to lookup
+ * @final_dst: final destination address for ipsec lookup
+ *
+ * This function performs a route lookup on the given flow.
+ *
+ * It returns a valid dst pointer on success, or a pointer encoded
+ * error code.
+ */
+struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6,
+ const struct in6_addr *final_dst)
+{
+ struct dst_entry *dst = NULL;
+ int err;
+
+ err = ip6_dst_lookup_tail(sock_net(sk), sk, &dst, fl6);
+ if (err)
+ return ERR_PTR(err);
+ if (final_dst)
+ fl6->daddr = *final_dst;
+
+ return xfrm_lookup_route(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
+}
+EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
+
+/**
+ * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow
+ * @sk: socket which provides the dst cache and route info
+ * @fl6: flow to lookup
+ * @final_dst: final destination address for ipsec lookup
+ * @connected: whether @sk is connected or not
+ *
+ * This function performs a route lookup on the given flow with the
+ * possibility of using the cached route in the socket if it is valid.
+ * It will take the socket dst lock when operating on the dst cache.
+ * As a result, this function can only be used in process context.
+ *
+ * In addition, for a connected socket, cache the dst in the socket
+ * if the current cache is not valid.
+ *
+ * It returns a valid dst pointer on success, or a pointer encoded
+ * error code.
+ */
+struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
+ const struct in6_addr *final_dst,
+ bool connected)
+{
+ struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
+
+ dst = ip6_sk_dst_check(sk, dst, fl6);
+ if (dst)
+ return dst;
+
+ dst = ip6_dst_lookup_flow(sk, fl6, final_dst);
+ if (connected && !IS_ERR(dst))
+ ip6_sk_dst_store_flow(sk, dst_clone(dst), fl6);
+
+ return dst;
+}
+EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow);
+
+static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src,
+ gfp_t gfp)
+{
+ return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
+}
+
+static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src,
+ gfp_t gfp)
+{
+ return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
+}
+
+static void ip6_append_data_mtu(unsigned int *mtu,
+ int *maxfraglen,
+ unsigned int fragheaderlen,
+ struct sk_buff *skb,
+ struct rt6_info *rt,
+ unsigned int orig_mtu)
+{
+ if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
+ if (!skb) {
+ /* first fragment, reserve header_len */
+ *mtu = orig_mtu - rt->dst.header_len;
+
+ } else {
+ /*
+ * this fragment is not first, the headers
+ * space is regarded as data space.
+ */
+ *mtu = orig_mtu;
+ }
+ *maxfraglen = ((*mtu - fragheaderlen) & ~7)
+ + fragheaderlen - sizeof(struct frag_hdr);
+ }
+}
+
+static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
+ struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6,
+ struct rt6_info *rt, struct flowi6 *fl6)
+{
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ unsigned int mtu;
+ struct ipv6_txoptions *opt = ipc6->opt;
+
+ /*
+ * setup for corking
+ */
+ if (opt) {
+ if (WARN_ON(v6_cork->opt))
+ return -EINVAL;
+
+ v6_cork->opt = kzalloc(sizeof(*opt), sk->sk_allocation);
+ if (unlikely(!v6_cork->opt))
+ return -ENOBUFS;
+
+ v6_cork->opt->tot_len = sizeof(*opt);
+ v6_cork->opt->opt_flen = opt->opt_flen;
+ v6_cork->opt->opt_nflen = opt->opt_nflen;
+
+ v6_cork->opt->dst0opt = ip6_opt_dup(opt->dst0opt,
+ sk->sk_allocation);
+ if (opt->dst0opt && !v6_cork->opt->dst0opt)
+ return -ENOBUFS;
+
+ v6_cork->opt->dst1opt = ip6_opt_dup(opt->dst1opt,
+ sk->sk_allocation);
+ if (opt->dst1opt && !v6_cork->opt->dst1opt)
+ return -ENOBUFS;
+
+ v6_cork->opt->hopopt = ip6_opt_dup(opt->hopopt,
+ sk->sk_allocation);
+ if (opt->hopopt && !v6_cork->opt->hopopt)
+ return -ENOBUFS;
+
+ v6_cork->opt->srcrt = ip6_rthdr_dup(opt->srcrt,
+ sk->sk_allocation);
+ if (opt->srcrt && !v6_cork->opt->srcrt)
+ return -ENOBUFS;
+
+ /* need source address above miyazawa*/
+ }
+ dst_hold(&rt->dst);
+ cork->base.dst = &rt->dst;
+ cork->fl.u.ip6 = *fl6;
+ v6_cork->hop_limit = ipc6->hlimit;
+ v6_cork->tclass = ipc6->tclass;
+ if (rt->dst.flags & DST_XFRM_TUNNEL)
+ mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
+ READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst);
+ else
+ mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
+ READ_ONCE(rt->dst.dev->mtu) : dst_mtu(xfrm_dst_path(&rt->dst));
+ if (np->frag_size < mtu) {
+ if (np->frag_size)
+ mtu = np->frag_size;
+ }
+ if (mtu < IPV6_MIN_MTU)
+ return -EINVAL;
+ cork->base.fragsize = mtu;
+ cork->base.gso_size = ipc6->gso_size;
+ cork->base.tx_flags = 0;
+ sock_tx_timestamp(sk, ipc6->sockc.tsflags, &cork->base.tx_flags);
+
+ if (dst_allfrag(xfrm_dst_path(&rt->dst)))
+ cork->base.flags |= IPCORK_ALLFRAG;
+ cork->base.length = 0;
+
+ cork->base.transmit_time = ipc6->sockc.transmit_time;
+
+ return 0;
+}
+
+static int __ip6_append_data(struct sock *sk,
+ struct flowi6 *fl6,
+ struct sk_buff_head *queue,
+ struct inet_cork *cork,
+ struct inet6_cork *v6_cork,
+ struct page_frag *pfrag,
+ int getfrag(void *from, char *to, int offset,
+ int len, int odd, struct sk_buff *skb),
+ void *from, int length, int transhdrlen,
+ unsigned int flags, struct ipcm6_cookie *ipc6)
+{
+ struct sk_buff *skb, *skb_prev = NULL;
+ unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu;
+ int exthdrlen = 0;
+ int dst_exthdrlen = 0;
+ int hh_len;
+ int copy;
+ int err;
+ int offset = 0;
+ u32 tskey = 0;
+ struct rt6_info *rt = (struct rt6_info *)cork->dst;
+ struct ipv6_txoptions *opt = v6_cork->opt;
+ int csummode = CHECKSUM_NONE;
+ unsigned int maxnonfragsize, headersize;
+ unsigned int wmem_alloc_delta = 0;
+ bool paged;
+
+ skb = skb_peek_tail(queue);
+ if (!skb) {
+ exthdrlen = opt ? opt->opt_flen : 0;
+ dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len;
+ }
+
+ paged = !!cork->gso_size;
+ mtu = cork->gso_size ? IP6_MAX_MTU : cork->fragsize;
+ orig_mtu = mtu;
+
+ if (cork->tx_flags & SKBTX_ANY_SW_TSTAMP &&
+ sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)
+ tskey = sk->sk_tskey++;
+
+ hh_len = LL_RESERVED_SPACE(rt->dst.dev);
+
+ fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
+ (opt ? opt->opt_nflen : 0);
+ maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen -
+ sizeof(struct frag_hdr);
+
+ headersize = sizeof(struct ipv6hdr) +
+ (opt ? opt->opt_flen + opt->opt_nflen : 0) +
+ (dst_allfrag(&rt->dst) ?
+ sizeof(struct frag_hdr) : 0) +
+ rt->rt6i_nfheader_len;
+
+ /* as per RFC 7112 section 5, the entire IPv6 Header Chain must fit
+ * the first fragment
+ */
+ if (headersize + transhdrlen > mtu)
+ goto emsgsize;
+
+ if (cork->length + length > mtu - headersize && ipc6->dontfrag &&
+ (sk->sk_protocol == IPPROTO_UDP ||
+ sk->sk_protocol == IPPROTO_RAW)) {
+ ipv6_local_rxpmtu(sk, fl6, mtu - headersize +
+ sizeof(struct ipv6hdr));
+ goto emsgsize;
+ }
+
+ if (ip6_sk_ignore_df(sk))
+ maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN;
+ else
+ maxnonfragsize = mtu;
+
+ if (cork->length + length > maxnonfragsize - headersize) {
+emsgsize:
+ pmtu = max_t(int, mtu - headersize + sizeof(struct ipv6hdr), 0);
+ ipv6_local_error(sk, EMSGSIZE, fl6, pmtu);
+ return -EMSGSIZE;
+ }
+
+ /* CHECKSUM_PARTIAL only with no extension headers and when
+ * we are not going to fragment
+ */
+ if (transhdrlen && sk->sk_protocol == IPPROTO_UDP &&
+ headersize == sizeof(struct ipv6hdr) &&
+ length <= mtu - headersize &&
+ (!(flags & MSG_MORE) || cork->gso_size) &&
+ rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM))
+ csummode = CHECKSUM_PARTIAL;
+
+ /*
+ * 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
+ */
+
+ cork->length += length;
+ if (!skb)
+ goto alloc_new_skb;
+
+ while (length > 0) {
+ /* Check if the remaining data fits into current packet. */
+ copy = (cork->length <= mtu && !(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;
+ unsigned int pagedlen = 0;
+alloc_new_skb:
+ /* There's no room in the current skb */
+ if (skb)
+ fraggap = skb->len - maxfraglen;
+ else
+ fraggap = 0;
+ /* update mtu and maxfraglen if necessary */
+ if (!skb || !skb_prev)
+ ip6_append_data_mtu(&mtu, &maxfraglen,
+ fragheaderlen, skb, rt,
+ orig_mtu);
+
+ skb_prev = skb;
+
+ /*
+ * If remaining data exceeds the mtu,
+ * we know we need more fragment(s).
+ */
+ datalen = length + fraggap;
+
+ if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
+ datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
+ fraglen = datalen + fragheaderlen;
+
+ if ((flags & MSG_MORE) &&
+ !(rt->dst.dev->features&NETIF_F_SG))
+ alloclen = mtu;
+ else if (!paged)
+ alloclen = fraglen;
+ else {
+ alloclen = min_t(int, fraglen, MAX_HEADER);
+ pagedlen = fraglen - alloclen;
+ }
+
+ alloclen += dst_exthdrlen;
+
+ if (datalen != length + fraggap) {
+ /*
+ * this is not the last fragment, the trailer
+ * space is regarded as data space.
+ */
+ datalen += rt->dst.trailer_len;
+ }
+
+ alloclen += rt->dst.trailer_len;
+ fraglen = datalen + fragheaderlen;
+
+ /*
+ * 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);
+
+ copy = datalen - transhdrlen - fraggap - pagedlen;
+ if (copy < 0) {
+ err = -EINVAL;
+ goto error;
+ }
+ if (transhdrlen) {
+ skb = sock_alloc_send_skb(sk,
+ alloclen + hh_len,
+ (flags & MSG_DONTWAIT), &err);
+ } else {
+ skb = NULL;
+ if (refcount_read(&sk->sk_wmem_alloc) + wmem_alloc_delta <=
+ 2 * sk->sk_sndbuf)
+ skb = alloc_skb(alloclen + hh_len,
+ sk->sk_allocation);
+ if (unlikely(!skb))
+ err = -ENOBUFS;
+ }
+ if (!skb)
+ goto error;
+ /*
+ * Fill in the control structures
+ */
+ skb->protocol = htons(ETH_P_IPV6);
+ skb->ip_summed = csummode;
+ skb->csum = 0;
+ /* reserve for fragmentation and ipsec header */
+ skb_reserve(skb, hh_len + sizeof(struct frag_hdr) +
+ dst_exthdrlen);
+
+ /* Only the initial fragment is time stamped */
+ skb_shinfo(skb)->tx_flags = cork->tx_flags;
+ cork->tx_flags = 0;
+ skb_shinfo(skb)->tskey = tskey;
+ tskey = 0;
+
+ /*
+ * Find where to start putting bytes
+ */
+ data = skb_put(skb, fraglen - pagedlen);
+ skb_set_network_header(skb, exthdrlen);
+ data += fragheaderlen;
+ skb->transport_header = (skb->network_header +
+ fragheaderlen);
+ 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;
+ pskb_trim_unique(skb_prev, maxfraglen);
+ }
+ if (copy > 0 &&
+ getfrag(from, data + transhdrlen, offset,
+ copy, fraggap, skb) < 0) {
+ err = -EFAULT;
+ kfree_skb(skb);
+ goto error;
+ }
+
+ offset += copy;
+ length -= copy + transhdrlen;
+ transhdrlen = 0;
+ exthdrlen = 0;
+ dst_exthdrlen = 0;
+
+ if ((flags & MSG_CONFIRM) && !skb_prev)
+ skb_set_dst_pending_confirm(skb, 1);
+
+ /*
+ * Put the packet on the pending queue
+ */
+ if (!skb->destructor) {
+ skb->destructor = sock_wfree;
+ skb->sk = sk;
+ wmem_alloc_delta += skb->truesize;
+ }
+ __skb_queue_tail(queue, skb);
+ continue;
+ }
+
+ if (copy > length)
+ copy = length;
+
+ if (!(rt->dst.dev->features&NETIF_F_SG) &&
+ skb_tailroom(skb) >= copy) {
+ 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;
+
+ err = -ENOMEM;
+ if (!sk_page_frag_refill(sk, pfrag))
+ goto error;
+
+ if (!skb_can_coalesce(skb, i, pfrag->page,
+ pfrag->offset)) {
+ err = -EMSGSIZE;
+ if (i == MAX_SKB_FRAGS)
+ goto error;
+
+ __skb_fill_page_desc(skb, i, pfrag->page,
+ pfrag->offset, 0);
+ skb_shinfo(skb)->nr_frags = ++i;
+ get_page(pfrag->page);
+ }
+ copy = min_t(int, copy, pfrag->size - pfrag->offset);
+ if (getfrag(from,
+ page_address(pfrag->page) + pfrag->offset,
+ offset, copy, skb->len, skb) < 0)
+ goto error_efault;
+
+ pfrag->offset += copy;
+ skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
+ skb->len += copy;
+ skb->data_len += copy;
+ skb->truesize += copy;
+ wmem_alloc_delta += copy;
+ }
+ offset += copy;
+ length -= copy;
+ }
+
+ if (wmem_alloc_delta)
+ refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc);
+ return 0;
+
+error_efault:
+ err = -EFAULT;
+error:
+ cork->length -= length;
+ IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
+ refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc);
+ 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,
+ struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
+ struct rt6_info *rt, unsigned int flags)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ int exthdrlen;
+ int err;
+
+ if (flags&MSG_PROBE)
+ return 0;
+ if (skb_queue_empty(&sk->sk_write_queue)) {
+ /*
+ * setup for corking
+ */
+ err = ip6_setup_cork(sk, &inet->cork, &np->cork,
+ ipc6, rt, fl6);
+ if (err)
+ return err;
+
+ exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
+ length += exthdrlen;
+ transhdrlen += exthdrlen;
+ } else {
+ fl6 = &inet->cork.fl.u.ip6;
+ transhdrlen = 0;
+ }
+
+ return __ip6_append_data(sk, fl6, &sk->sk_write_queue, &inet->cork.base,
+ &np->cork, sk_page_frag(sk), getfrag,
+ from, length, transhdrlen, flags, ipc6);
+}
+EXPORT_SYMBOL_GPL(ip6_append_data);
+
+static void ip6_cork_release(struct inet_cork_full *cork,
+ struct inet6_cork *v6_cork)
+{
+ if (v6_cork->opt) {
+ kfree(v6_cork->opt->dst0opt);
+ kfree(v6_cork->opt->dst1opt);
+ kfree(v6_cork->opt->hopopt);
+ kfree(v6_cork->opt->srcrt);
+ kfree(v6_cork->opt);
+ v6_cork->opt = NULL;
+ }
+
+ if (cork->base.dst) {
+ dst_release(cork->base.dst);
+ cork->base.dst = NULL;
+ cork->base.flags &= ~IPCORK_ALLFRAG;
+ }
+ memset(&cork->fl, 0, sizeof(cork->fl));
+}
+
+struct sk_buff *__ip6_make_skb(struct sock *sk,
+ struct sk_buff_head *queue,
+ struct inet_cork_full *cork,
+ struct inet6_cork *v6_cork)
+{
+ struct sk_buff *skb, *tmp_skb;
+ struct sk_buff **tail_skb;
+ struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ struct net *net = sock_net(sk);
+ struct ipv6hdr *hdr;
+ struct ipv6_txoptions *opt = v6_cork->opt;
+ struct rt6_info *rt = (struct rt6_info *)cork->base.dst;
+ struct flowi6 *fl6 = &cork->fl.u.ip6;
+ unsigned char proto = fl6->flowi6_proto;
+
+ skb = __skb_dequeue(queue);
+ if (!skb)
+ goto out;
+ tail_skb = &(skb_shinfo(skb)->frag_list);
+
+ /* move skb->data to ip header from ext header */
+ if (skb->data < skb_network_header(skb))
+ __skb_pull(skb, skb_network_offset(skb));
+ while ((tmp_skb = __skb_dequeue(queue)) != NULL) {
+ __skb_pull(tmp_skb, skb_network_header_len(skb));
+ *tail_skb = tmp_skb;
+ tail_skb = &(tmp_skb->next);
+ skb->len += tmp_skb->len;
+ skb->data_len += tmp_skb->len;
+ skb->truesize += tmp_skb->truesize;
+ tmp_skb->destructor = NULL;
+ tmp_skb->sk = NULL;
+ }
+
+ /* Allow local fragmentation. */
+ skb->ignore_df = ip6_sk_ignore_df(sk);
+
+ *final_dst = fl6->daddr;
+ __skb_pull(skb, skb_network_header_len(skb));
+ 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, &fl6->saddr);
+
+ skb_push(skb, sizeof(struct ipv6hdr));
+ skb_reset_network_header(skb);
+ hdr = ipv6_hdr(skb);
+
+ ip6_flow_hdr(hdr, v6_cork->tclass,
+ ip6_make_flowlabel(net, skb, fl6->flowlabel,
+ ip6_autoflowlabel(net, np), fl6));
+ hdr->hop_limit = v6_cork->hop_limit;
+ hdr->nexthdr = proto;
+ hdr->saddr = fl6->saddr;
+ hdr->daddr = *final_dst;
+
+ skb->priority = sk->sk_priority;
+ skb->mark = sk->sk_mark;
+
+ skb->tstamp = cork->base.transmit_time;
+
+ skb_dst_set(skb, dst_clone(&rt->dst));
+ IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);
+ if (proto == IPPROTO_ICMPV6) {
+ struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
+
+ ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type);
+ ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
+ }
+
+ ip6_cork_release(cork, v6_cork);
+out:
+ return skb;
+}
+
+int ip6_send_skb(struct sk_buff *skb)
+{
+ struct net *net = sock_net(skb->sk);
+ struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
+ int err;
+
+ err = ip6_local_out(net, skb->sk, skb);
+ if (err) {
+ if (err > 0)
+ err = net_xmit_errno(err);
+ if (err)
+ IP6_INC_STATS(net, rt->rt6i_idev,
+ IPSTATS_MIB_OUTDISCARDS);
+ }
+
+ return err;
+}
+
+int ip6_push_pending_frames(struct sock *sk)
+{
+ struct sk_buff *skb;
+
+ skb = ip6_finish_skb(sk);
+ if (!skb)
+ return 0;
+
+ return ip6_send_skb(skb);
+}
+EXPORT_SYMBOL_GPL(ip6_push_pending_frames);
+
+static void __ip6_flush_pending_frames(struct sock *sk,
+ struct sk_buff_head *queue,
+ struct inet_cork_full *cork,
+ struct inet6_cork *v6_cork)
+{
+ struct sk_buff *skb;
+
+ while ((skb = __skb_dequeue_tail(queue)) != NULL) {
+ if (skb_dst(skb))
+ IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)),
+ IPSTATS_MIB_OUTDISCARDS);
+ kfree_skb(skb);
+ }
+
+ ip6_cork_release(cork, v6_cork);
+}
+
+void ip6_flush_pending_frames(struct sock *sk)
+{
+ __ip6_flush_pending_frames(sk, &sk->sk_write_queue,
+ &inet_sk(sk)->cork, &inet6_sk(sk)->cork);
+}
+EXPORT_SYMBOL_GPL(ip6_flush_pending_frames);
+
+struct sk_buff *ip6_make_skb(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,
+ struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
+ struct rt6_info *rt, unsigned int flags,
+ struct inet_cork_full *cork)
+{
+ struct inet6_cork v6_cork;
+ struct sk_buff_head queue;
+ int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
+ int err;
+
+ if (flags & MSG_PROBE)
+ return NULL;
+
+ __skb_queue_head_init(&queue);
+
+ cork->base.flags = 0;
+ cork->base.addr = 0;
+ cork->base.opt = NULL;
+ cork->base.dst = NULL;
+ v6_cork.opt = NULL;
+ err = ip6_setup_cork(sk, cork, &v6_cork, ipc6, rt, fl6);
+ if (err) {
+ ip6_cork_release(cork, &v6_cork);
+ return ERR_PTR(err);
+ }
+ if (ipc6->dontfrag < 0)
+ ipc6->dontfrag = inet6_sk(sk)->dontfrag;
+
+ err = __ip6_append_data(sk, fl6, &queue, &cork->base, &v6_cork,
+ ¤t->task_frag, getfrag, from,
+ length + exthdrlen, transhdrlen + exthdrlen,
+ flags, ipc6);
+ if (err) {
+ __ip6_flush_pending_frames(sk, &queue, cork, &v6_cork);
+ return ERR_PTR(err);
+ }
+
+ return __ip6_make_skb(sk, &queue, cork, &v6_cork);
+}