vxlan: consolidate vxlan_xmit_skb and vxlan6_xmit_skb

There's a lot of code duplication. Factor out the duplicate code to a new
function shared between IPv4 and IPv6 xmit path.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index fe3fd48..65f5247 100644 (file)
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -1684,19 +1684,14 @@ static void vxlan_build_gbp_hdr(struct vxlanhdr *vxh, u32 vxflags,
        gbp->policy_id = htons(md->gbp & VXLAN_GBP_ID_MASK);
 }
 
-#if IS_ENABLED(CONFIG_IPV6)
-static int vxlan6_xmit_skb(struct dst_entry *dst, struct sock *sk,
-                          struct sk_buff *skb,
-                          struct net_device *dev, struct in6_addr *saddr,
-                          struct in6_addr *daddr, __u8 prio, __u8 ttl,
-                          __be16 src_port, __be16 dst_port, __be32 vni,
-                          struct vxlan_metadata *md, bool xnet, u32 vxflags,
+static int vxlan_build_skb(struct sk_buff *skb, struct dst_entry *dst,
+                          int iphdr_len, __be32 vni,
+                          struct vxlan_metadata *md, u32 vxflags,
                           bool udp_sum)
 {
        struct vxlanhdr *vxh;
        int min_headroom;
        int err;
-       bool nocheck = !udp_sum;
        int type = udp_sum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
        u16 hdrlen = sizeof(struct vxlanhdr);
 
@@ -1713,93 +1708,8 @@ static int vxlan6_xmit_skb(struct dst_entry *dst, struct sock *sk,
                }
        }
 
-       skb_scrub_packet(skb, xnet);
-
        min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len
-                       + VXLAN_HLEN + sizeof(struct ipv6hdr)
-                       + (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);
-
-       /* Need space for new headers (invalidates iph ptr) */
-       err = skb_cow_head(skb, min_headroom);
-       if (unlikely(err)) {
-               kfree_skb(skb);
-               goto err;
-       }
-
-       skb = vlan_hwaccel_push_inside(skb);
-       if (WARN_ON(!skb)) {
-               err = -ENOMEM;
-               goto err;
-       }
-
-       skb = iptunnel_handle_offloads(skb, udp_sum, type);
-       if (IS_ERR(skb)) {
-               err = -EINVAL;
-               goto err;
-       }
-
-       vxh = (struct vxlanhdr *) __skb_push(skb, sizeof(*vxh));
-       vxh->vx_flags = htonl(VXLAN_HF_VNI);
-       vxh->vx_vni = vni;
-
-       if (type & SKB_GSO_TUNNEL_REMCSUM) {
-               u32 data = (skb_checksum_start_offset(skb) - hdrlen) >>
-                          VXLAN_RCO_SHIFT;
-
-               if (skb->csum_offset == offsetof(struct udphdr, check))
-                       data |= VXLAN_RCO_UDP;
-
-               vxh->vx_vni |= htonl(data);
-               vxh->vx_flags |= htonl(VXLAN_HF_RCO);
-
-               if (!skb_is_gso(skb)) {
-                       skb->ip_summed = CHECKSUM_NONE;
-                       skb->encapsulation = 0;
-               }
-       }
-
-       if (vxflags & VXLAN_F_GBP)
-               vxlan_build_gbp_hdr(vxh, vxflags, md);
-
-       skb_set_inner_protocol(skb, htons(ETH_P_TEB));
-
-       udp_tunnel6_xmit_skb(dst, sk, skb, dev, saddr, daddr, prio,
-                            ttl, src_port, dst_port, nocheck);
-       return 0;
-err:
-       dst_release(dst);
-       return err;
-}
-#endif
-
-static int vxlan_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb,
-                         __be32 src, __be32 dst, __u8 tos, __u8 ttl, __be16 df,
-                         __be16 src_port, __be16 dst_port, __be32 vni,
-                         struct vxlan_metadata *md, bool xnet, u32 vxflags,
-                         bool udp_sum)
-{
-       struct vxlanhdr *vxh;
-       int min_headroom;
-       int err;
-       bool nocheck = !udp_sum;
-       int type = udp_sum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
-       u16 hdrlen = sizeof(struct vxlanhdr);
-
-       if ((vxflags & VXLAN_F_REMCSUM_TX) &&
-           skb->ip_summed == CHECKSUM_PARTIAL) {
-               int csum_start = skb_checksum_start_offset(skb);
-
-               if (csum_start <= VXLAN_MAX_REMCSUM_START &&
-                   !(csum_start & VXLAN_RCO_SHIFT_MASK) &&
-                   (skb->csum_offset == offsetof(struct udphdr, check) ||
-                    skb->csum_offset == offsetof(struct tcphdr, check))) {
-                       udp_sum = false;
-                       type |= SKB_GSO_TUNNEL_REMCSUM;
-               }
-       }
-
-       min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
-                       + VXLAN_HLEN + sizeof(struct iphdr)
+                       + VXLAN_HLEN + iphdr_len
                        + (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);
 
        /* Need space for new headers (invalidates iph ptr) */
@@ -1841,9 +1751,6 @@ static int vxlan_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *sk
                vxlan_build_gbp_hdr(vxh, vxflags, md);
 
        skb_set_inner_protocol(skb, htons(ETH_P_TEB));
-
-       udp_tunnel_xmit_skb(rt, sk, skb, src, dst, tos, ttl, df,
-                           src_port, dst_port, xnet, nocheck);
        return 0;
 }
 
@@ -1960,6 +1867,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
        int err;
        u32 flags = vxlan->flags;
        bool udp_sum = false;
+       bool xnet = !net_eq(vxlan->net, dev_net(vxlan->dev));
 
        info = skb_tunnel_info(skb);
 
@@ -2064,16 +1972,14 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 
                tos = ip_tunnel_ecn_encap(tos, old_iph, skb);
                ttl = ttl ? : ip4_dst_hoplimit(&rt->dst);
-               err = vxlan_xmit_skb(rt, sk, skb, saddr,
-                                    dst->sin.sin_addr.s_addr, tos, ttl, df,
-                                    src_port, dst_port, htonl(vni << 8), md,
-                                    !net_eq(vxlan->net, dev_net(vxlan->dev)),
-                                    flags, udp_sum);
-               if (err < 0) {
-                       /* skb is already freed. */
-                       skb = NULL;
-                       goto rt_tx_error;
-               }
+               err = vxlan_build_skb(skb, &rt->dst, sizeof(struct iphdr),
+                                     htonl(vni << 8), md, flags, udp_sum);
+               if (err < 0)
+                       goto xmit_tx_error;
+
+               udp_tunnel_xmit_skb(rt, sk, skb, saddr,
+                                   dst->sin.sin_addr.s_addr, tos, ttl, df,
+                                   src_port, dst_port, xnet, !udp_sum);
 #if IS_ENABLED(CONFIG_IPV6)
        } else {
                struct dst_entry *ndst;
@@ -2122,10 +2028,16 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
                        udp_sum = !(flags & VXLAN_F_UDP_ZERO_CSUM6_TX);
 
                ttl = ttl ? : ip6_dst_hoplimit(ndst);
-               err = vxlan6_xmit_skb(ndst, sk, skb, dev, &saddr, &dst->sin6.sin6_addr,
-                                     0, ttl, src_port, dst_port, htonl(vni << 8), md,
-                                     !net_eq(vxlan->net, dev_net(vxlan->dev)),
-                                     flags, udp_sum);
+               skb_scrub_packet(skb, xnet);
+               err = vxlan_build_skb(skb, ndst, sizeof(struct ipv6hdr),
+                                     htonl(vni << 8), md, flags, udp_sum);
+               if (err < 0) {
+                       dst_release(ndst);
+                       return;
+               }
+               udp_tunnel6_xmit_skb(ndst, sk, skb, dev,
+                                    &saddr, &dst->sin6.sin6_addr,
+                                    0, ttl, src_port, dst_port, !udp_sum);
 #endif
        }
 
@@ -2135,6 +2047,9 @@ drop:
        dev->stats.tx_dropped++;
        goto tx_free;
 
+xmit_tx_error:
+       /* skb is already freed. */
+       skb = NULL;
 rt_tx_error:
        ip_rt_put(rt);
 tx_error: