ip6_gre: Refactor ip6gre xmit codes

This patch refactors the ip6gre_xmit_{ipv4, ipv6}.
It is a prep work to add the ip6erspan tunnel.

Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 4cfd8e0696fe77f6d7af7ca3579a2418aef972f6..907d2e8405e2eaebb19608f99fccc347eda23e58 100644 (file)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -496,6 +496,78 @@ static int gre_handle_offloads(struct sk_buff *skb, bool csum)
                                        csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
 }
 
+static void prepare_ip6gre_xmit_ipv4(struct sk_buff *skb,
+                                    struct net_device *dev,
+                                    struct flowi6 *fl6, __u8 *dsfield,
+                                    int *encap_limit)
+{
+       const struct iphdr *iph = ip_hdr(skb);
+       struct ip6_tnl *t = netdev_priv(dev);
+
+       if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
+               *encap_limit = t->parms.encap_limit;
+
+       memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
+
+       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);
+}
+
+static int prepare_ip6gre_xmit_ipv6(struct sk_buff *skb,
+                                   struct net_device *dev,
+                                   struct flowi6 *fl6, __u8 *dsfield,
+                                   int *encap_limit)
+{
+       struct ipv6hdr *ipv6h = ipv6_hdr(skb);
+       struct ip6_tnl *t = netdev_priv(dev);
+       __u16 offset;
+
+       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;
+
+               tel = (struct ipv6_tlv_tnl_enc_lim *)&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;
+       } 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));
+
+       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;
+
+       fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
+
+       return 0;
+}
+
 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
                               struct net_device *dev, __u8 dsfield,
                               struct flowi6 *fl6, int encap_limit,
@@ -527,7 +599,6 @@ static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 {
        struct ip6_tnl *t = netdev_priv(dev);
-       const struct iphdr  *iph = ip_hdr(skb);
        int encap_limit = -1;
        struct flowi6 fl6;
        __u8 dsfield;
@@ -536,21 +607,7 @@ static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 
        memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 
-       if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
-               encap_limit = t->parms.encap_limit;
-
-       memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
-
-       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);
+       prepare_ip6gre_xmit_ipv4(skb, dev, &fl6, &dsfield, &encap_limit);
 
        err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
        if (err)
@@ -574,7 +631,6 @@ static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
        struct ip6_tnl *t = netdev_priv(dev);
        struct ipv6hdr *ipv6h = ipv6_hdr(skb);
        int encap_limit = -1;
-       __u16 offset;
        struct flowi6 fl6;
        __u8 dsfield;
        __u32 mtu;
@@ -583,37 +639,8 @@ static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
        if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
                return -1;
 
-       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 = (struct ipv6_tlv_tnl_enc_lim *)&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;
-       } 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));
-
-       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;
-
-       fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
+       if (prepare_ip6gre_xmit_ipv6(skb, dev, &fl6, &dsfield, &encap_limit))
+               return -1;
 
        if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
                return -1;