ip6_tunnel: simplify transmit path

Merge ip{4,6}ip6_tnl_xmit functions into one universal
ipxip6_tnl_xmit in preparation for adding MPLS support.

Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 4703b09..dae6f71 100644 (file)
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1253,22 +1253,22 @@ tx_err_dst_release:
 EXPORT_SYMBOL(ip6_tnl_xmit);
 
 static inline int
-ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
+ipxip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev,
+               u8 protocol)
 {
        struct ip6_tnl *t = netdev_priv(dev);
+       struct ipv6hdr *ipv6h;
        const struct iphdr  *iph;
        int encap_limit = -1;
+       __u16 offset;
        struct flowi6 fl6;
-       __u8 dsfield;
+       __u8 dsfield, orig_dsfield;
        __u32 mtu;
        u8 tproto;
        int err;
 
-       iph = ip_hdr(skb);
-       memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
-
        tproto = READ_ONCE(t->parms.proto);
-       if (tproto != IPPROTO_IPIP && tproto != 0)
+       if (tproto != protocol && tproto != 0)
                return -1;
 
        if (t->parms.collect_md) {
@@ -1281,129 +1281,101 @@ ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
                        return -1;
                key = &tun_info->key;
                memset(&fl6, 0, sizeof(fl6));
-               fl6.flowi6_proto = IPPROTO_IPIP;
+               fl6.flowi6_proto = protocol;
                fl6.saddr = key->u.ipv6.src;
                fl6.daddr = key->u.ipv6.dst;
                fl6.flowlabel = key->label;
                dsfield =  key->tos;
+               switch (protocol) {
+               case IPPROTO_IPIP:
+                       iph = ip_hdr(skb);
+                       orig_dsfield = ipv4_get_dsfield(iph);
+                       break;
+               case IPPROTO_IPV6:
+                       ipv6h = ipv6_hdr(skb);
+                       orig_dsfield = ipv6_get_dsfield(ipv6h);
+                       break;
+               default:
+                       orig_dsfield = dsfield;
+                       break;
+               }
        } else {
                if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
                        encap_limit = t->parms.encap_limit;
+               if (protocol == IPPROTO_IPV6) {
+                       offset = ip6_tnl_parse_tlv_enc_lim(skb,
+                                               skb_network_header(skb));
+                       /* ip6_tnl_parse_tlv_enc_lim() might have
+                        * reallocated skb->head
+                        */
+                       if (offset > 0) {
+                               struct ipv6_tlv_tnl_enc_lim *tel;
 
-               memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
-               fl6.flowi6_proto = IPPROTO_IPIP;
-
-               if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
-                       dsfield = ipv4_get_dsfield(iph);
-               else
-                       dsfield = ip6_tclass(t->parms.flowinfo);
-               if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
-                       fl6.flowi6_mark = skb->mark;
-               else
-                       fl6.flowi6_mark = t->parms.fwmark;
-       }
-
-       fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
-       dsfield = INET_ECN_encapsulate(dsfield, ipv4_get_dsfield(iph));
-
-       if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
-               return -1;
-
-       skb_set_inner_ipproto(skb, IPPROTO_IPIP);
-
-       err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
-                          IPPROTO_IPIP);
-       if (err != 0) {
-               /* XXX: send ICMP error even if DF is not set. */
-               if (err == -EMSGSIZE)
-                       icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
-                                 htonl(mtu));
-               return -1;
-       }
-
-       return 0;
-}
-
-static inline int
-ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
-{
-       struct ip6_tnl *t = netdev_priv(dev);
-       struct ipv6hdr *ipv6h;
-       int encap_limit = -1;
-       __u16 offset;
-       struct flowi6 fl6;
-       __u8 dsfield;
-       __u32 mtu;
-       u8 tproto;
-       int err;
-
-       ipv6h = ipv6_hdr(skb);
-       tproto = READ_ONCE(t->parms.proto);
-       if ((tproto != IPPROTO_IPV6 && tproto != 0) ||
-           ip6_tnl_addr_conflict(t, ipv6h))
-               return -1;
-
-       if (t->parms.collect_md) {
-               struct ip_tunnel_info *tun_info;
-               const struct ip_tunnel_key *key;
-
-               tun_info = skb_tunnel_info(skb);
-               if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
-                            ip_tunnel_info_af(tun_info) != AF_INET6))
-                       return -1;
-               key = &tun_info->key;
-               memset(&fl6, 0, sizeof(fl6));
-               fl6.flowi6_proto = IPPROTO_IPV6;
-               fl6.saddr = key->u.ipv6.src;
-               fl6.daddr = key->u.ipv6.dst;
-               fl6.flowlabel = key->label;
-               dsfield = key->tos;
-       } else {
-               offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
-               /* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
-               ipv6h = ipv6_hdr(skb);
-               if (offset > 0) {
-                       struct ipv6_tlv_tnl_enc_lim *tel;
-
-                       tel = (void *)&skb_network_header(skb)[offset];
-                       if (tel->encap_limit == 0) {
-                               icmpv6_send(skb, ICMPV6_PARAMPROB,
-                                           ICMPV6_HDR_FIELD, offset + 2);
-                               return -1;
+                               tel = (void *)&skb_network_header(skb)[offset];
+                               if (tel->encap_limit == 0) {
+                                       icmpv6_send(skb, ICMPV6_PARAMPROB,
+                                               ICMPV6_HDR_FIELD, offset + 2);
+                                       return -1;
+                               }
+                               encap_limit = tel->encap_limit - 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(&fl6, &t->fl.u.ip6, sizeof(fl6));
-               fl6.flowi6_proto = IPPROTO_IPV6;
+               fl6.flowi6_proto = protocol;
 
-               if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
-                       dsfield = ipv6_get_dsfield(ipv6h);
-               else
-                       dsfield = ip6_tclass(t->parms.flowinfo);
-               if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
-                       fl6.flowlabel |= ip6_flowlabel(ipv6h);
                if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
                        fl6.flowi6_mark = skb->mark;
                else
                        fl6.flowi6_mark = t->parms.fwmark;
+               switch (protocol) {
+               case IPPROTO_IPIP:
+                       iph = ip_hdr(skb);
+                       orig_dsfield = ipv4_get_dsfield(iph);
+                       if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
+                               dsfield = orig_dsfield;
+                       else
+                               dsfield = ip6_tclass(t->parms.flowinfo);
+                       break;
+               case IPPROTO_IPV6:
+                       ipv6h = ipv6_hdr(skb);
+                       orig_dsfield = ipv6_get_dsfield(ipv6h);
+                       if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
+                               dsfield = orig_dsfield;
+                       else
+                               dsfield = ip6_tclass(t->parms.flowinfo);
+                       if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
+                               fl6.flowlabel |= ip6_flowlabel(ipv6h);
+                       break;
+               default:
+                       break;
+               }
        }
 
        fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
-       dsfield = INET_ECN_encapsulate(dsfield, ipv6_get_dsfield(ipv6h));
+       dsfield = INET_ECN_encapsulate(dsfield, orig_dsfield);
 
        if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
                return -1;
 
-       skb_set_inner_ipproto(skb, IPPROTO_IPV6);
+       skb_set_inner_ipproto(skb, protocol);
 
        err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
-                          IPPROTO_IPV6);
+                          protocol);
        if (err != 0) {
+               /* XXX: send ICMP error even if DF is not set. */
                if (err == -EMSGSIZE)
-                       icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+                       switch (protocol) {
+                       case IPPROTO_IPIP:
+                               icmp_send(skb, ICMP_DEST_UNREACH,
+                                         ICMP_FRAG_NEEDED, htonl(mtu));
+                               break;
+                       case IPPROTO_IPV6:
+                               icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+                               break;
+                       default:
+                               break;
+                       }
                return -1;
        }
 
@@ -1415,6 +1387,7 @@ ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
        struct ip6_tnl *t = netdev_priv(dev);
        struct net_device_stats *stats = &t->dev->stats;
+       u8 ipproto;
        int ret;
 
        if (!pskb_inet_may_pull(skb))
@@ -1422,15 +1395,18 @@ ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
        switch (skb->protocol) {
        case htons(ETH_P_IP):
-               ret = ip4ip6_tnl_xmit(skb, dev);
+               ipproto = IPPROTO_IPIP;
                break;
        case htons(ETH_P_IPV6):
-               ret = ip6ip6_tnl_xmit(skb, dev);
+               if (ip6_tnl_addr_conflict(t, ipv6_hdr(skb)))
+                       goto tx_err;
+               ipproto = IPPROTO_IPV6;
                break;
        default:
                goto tx_err;
        }
 
+       ret = ipxip6_tnl_xmit(skb, dev, ipproto);
        if (ret < 0)
                goto tx_err;