[IPV6] IP6TUNNEL: Split out generic routine in ip6ip6_xmit().

This enables to add IPv4/IPv6 specific handling later,

Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 985d106..4546bb9 100644 (file)
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -678,9 +678,13 @@ static inline int ip6_tnl_xmit_ctl(struct ip6_tnl *t)
        return ret;
 }
 /**
- * ip6ip6_tnl_xmit - encapsulate packet and send
+ * ip6_tnl_xmit2 - encapsulate packet and send
  *   @skb: the outgoing socket buffer
  *   @dev: the outgoing tunnel device
+ *   @dsfield: dscp code for outer header
+ *   @fl: flow of tunneled packet
+ *   @encap_limit: encapsulation limit
+ *   @pmtu: Path MTU is stored if packet is too big
  *
  * Description:
  *   Build new header and do some sanity checks on the packet before sending
@@ -688,62 +692,35 @@ static inline int ip6_tnl_xmit_ctl(struct ip6_tnl *t)
  *
  * Return:
  *   0
+ *   -1 fail
+ *   %-EMSGSIZE message too big. return mtu in this case.
  **/
 
-static int
-ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
+static int ip6_tnl_xmit2(struct sk_buff *skb,
+                        struct net_device *dev,
+                        __u8 dsfield,
+                        struct flowi *fl,
+                        int encap_limit,
+                        __u32 *pmtu)
 {
        struct ip6_tnl *t = netdev_priv(dev);
        struct net_device_stats *stats = &t->stat;
        struct ipv6hdr *ipv6h = skb->nh.ipv6h;
-       int encap_limit = -1;
        struct ipv6_tel_txoption opt;
-       __u16 offset;
-       struct flowi fl;
        struct dst_entry *dst;
        struct net_device *tdev;
        int mtu;
        int max_headroom = sizeof(struct ipv6hdr);
        u8 proto;
-       int err;
+       int err = -1;
        int pkt_len;
-       int dsfield;
-
-       if (t->recursion++) {
-               stats->collisions++;
-               goto tx_err;
-       }
-       if (skb->protocol != htons(ETH_P_IPV6) ||
-           !ip6_tnl_xmit_ctl(t) || ip6ip6_tnl_addr_conflict(t, ipv6h))
-               goto tx_err;
-
-       if ((offset = parse_tlv_tnl_enc_lim(skb, skb->nh.raw)) > 0) {
-               struct ipv6_tlv_tnl_enc_lim *tel;
-               tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->nh.raw[offset];
-               if (tel->encap_limit == 0) {
-                       icmpv6_send(skb, ICMPV6_PARAMPROB,
-                                   ICMPV6_HDR_FIELD, offset + 2, skb->dev);
-                       goto tx_err;
-               }
-               encap_limit = tel->encap_limit - 1;
-       } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
-               encap_limit = t->parms.encap_limit;
-
-       memcpy(&fl, &t->fl, sizeof (fl));
-       proto = fl.proto;
-
-       dsfield = ipv6_get_dsfield(ipv6h);
-       if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS))
-               fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
-       if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL))
-               fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK);
 
        if ((dst = ip6_tnl_dst_check(t)) != NULL)
                dst_hold(dst);
        else {
-               dst = ip6_route_output(NULL, &fl);
+               dst = ip6_route_output(NULL, fl);
 
-               if (dst->error || xfrm_lookup(&dst, &fl, NULL, 0) < 0)
+               if (dst->error || xfrm_lookup(&dst, fl, NULL, 0) < 0)
                        goto tx_err_link_failure;
        }
 
@@ -767,7 +744,8 @@ ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
        if (skb->dst)
                skb->dst->ops->update_pmtu(skb->dst, mtu);
        if (skb->len > mtu) {
-               icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
+               *pmtu = mtu;
+               err = -EMSGSIZE;
                goto tx_err_dst_release;
        }
 
@@ -793,20 +771,21 @@ ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 
        skb->h.raw = skb->nh.raw;
 
+       proto = fl->proto;
        if (encap_limit >= 0) {
                init_tel_txopt(&opt, encap_limit);
                ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
        }
        skb->nh.raw = skb_push(skb, sizeof(struct ipv6hdr));
        ipv6h = skb->nh.ipv6h;
-       *(__be32*)ipv6h = fl.fl6_flowlabel | htonl(0x60000000);
+       *(__be32*)ipv6h = fl->fl6_flowlabel | htonl(0x60000000);
        dsfield = INET_ECN_encapsulate(0, dsfield);
        ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield);
        ipv6h->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
        ipv6h->hop_limit = t->parms.hop_limit;
        ipv6h->nexthdr = proto;
-       ipv6_addr_copy(&ipv6h->saddr, &fl.fl6_src);
-       ipv6_addr_copy(&ipv6h->daddr, &fl.fl6_dst);
+       ipv6_addr_copy(&ipv6h->saddr, &fl->fl6_src);
+       ipv6_addr_copy(&ipv6h->daddr, &fl->fl6_dst);
        nf_reset(skb);
        pkt_len = skb->len;
        err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL,
@@ -820,13 +799,87 @@ ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
                stats->tx_aborted_errors++;
        }
        ip6_tnl_dst_store(t, dst);
-       t->recursion--;
        return 0;
 tx_err_link_failure:
        stats->tx_carrier_errors++;
        dst_link_failure(skb);
 tx_err_dst_release:
        dst_release(dst);
+       return err;
+}
+
+static inline int
+ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+       struct ip6_tnl *t = netdev_priv(dev);
+       struct ipv6hdr *ipv6h = skb->nh.ipv6h;
+       int encap_limit = -1;
+       __u16 offset;
+       struct flowi fl;
+       __u8 dsfield;
+       __u32 mtu;
+       int err;
+
+       if (!ip6_tnl_xmit_ctl(t) || ip6ip6_tnl_addr_conflict(t, ipv6h))
+               return -1;
+
+       if ((offset = parse_tlv_tnl_enc_lim(skb, skb->nh.raw)) > 0) {
+               struct ipv6_tlv_tnl_enc_lim *tel;
+               tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->nh.raw[offset];
+               if (tel->encap_limit == 0) {
+                       icmpv6_send(skb, ICMPV6_PARAMPROB,
+                                   ICMPV6_HDR_FIELD, offset + 2, skb->dev);
+                       return -1;
+               }
+               encap_limit = tel->encap_limit - 1;
+       } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
+               encap_limit = t->parms.encap_limit;
+
+       memcpy(&fl, &t->fl, sizeof (fl));
+       fl.proto = IPPROTO_IPV6;
+
+       dsfield = ipv6_get_dsfield(ipv6h);
+       if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS))
+               fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
+       if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL))
+               fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK);
+
+       err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu);
+       if (err != 0) {
+               if (err == -EMSGSIZE)
+                       icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
+               return -1;
+       }
+
+       return 0;
+}
+
+static int
+ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+       struct ip6_tnl *t = netdev_priv(dev);
+       struct net_device_stats *stats = &t->stat;
+       int ret;
+
+       if (t->recursion++) {
+               t->stat.collisions++;
+               goto tx_err;
+       }
+
+       switch (skb->protocol) {
+       case __constant_htons(ETH_P_IPV6):
+               ret = ip6ip6_tnl_xmit(skb, dev);
+               break;
+       default:
+               goto tx_err;
+       }
+
+       if (ret < 0)
+               goto tx_err;
+
+       t->recursion--;
+       return 0;
+
 tx_err:
        stats->tx_errors++;
        stats->tx_dropped++;
@@ -1088,7 +1141,7 @@ static void ip6ip6_tnl_dev_setup(struct net_device *dev)
        SET_MODULE_OWNER(dev);
        dev->uninit = ip6ip6_tnl_dev_uninit;
        dev->destructor = free_netdev;
-       dev->hard_start_xmit = ip6ip6_tnl_xmit;
+       dev->hard_start_xmit = ip6_tnl_xmit;
        dev->get_stats = ip6ip6_tnl_get_stats;
        dev->do_ioctl = ip6ip6_tnl_ioctl;
        dev->change_mtu = ip6ip6_tnl_change_mtu;