xfrm: prefer secpath_set over secpath_dup

secpath_set is a wrapper for secpath_dup that will not perform
an allocation if the secpath attached to the skb has a reference count
of one, i.e., it doesn't need to be COW'ed.

Also, secpath_dup doesn't attach the secpath to the skb, it leaves
this to the caller.

Use secpath_set in places that immediately assign the return value to
skb.

This allows to remove skb->sp without touching these spots again.

secpath_dup can eventually be removed in followup patch.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 19 insertions, 17 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ipsec.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_ipsec.c
index 8befc7a50f8c..ff85ce5791a3 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ipsec.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ipsec.c
@@ -1161,6 +1161,7 @@ void ixgbe_ipsec_rx(struct ixgbe_ring *rx_ring,
         struct xfrm_state *xs = NULL;
         struct ipv6hdr *ip6 = NULL;
         struct iphdr *ip4 = NULL;
+        struct sec_path *sp;
         void *daddr;
         __be32 spi;
         u8 *c_hdr;
@@ -1200,12 +1201,12 @@ void ixgbe_ipsec_rx(struct ixgbe_ring *rx_ring,
         if (unlikely(!xs))
                 return;
 
-        skb->sp = secpath_dup(skb->sp);
-        if (unlikely(!skb->sp))
+        sp = secpath_set(skb);
+        if (unlikely(!sp))
                 return;
 
-        skb->sp->xvec[skb->sp->len++] = xs;
-        skb->sp->olen++;
+        sp->xvec[sp->len++] = xs;
+        sp->olen++;
         xo = xfrm_offload(skb);
         xo->flags = CRYPTO_DONE;
         xo->status = CRYPTO_SUCCESS;
diff --git a/drivers/net/ethernet/intel/ixgbevf/ipsec.c b/drivers/net/ethernet/intel/ixgbevf/ipsec.c
index 07644e6bf498..5170dd9d8705 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ipsec.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ipsec.c
@@ -548,6 +548,7 @@ void ixgbevf_ipsec_rx(struct ixgbevf_ring *rx_ring,
         struct xfrm_state *xs = NULL;
         struct ipv6hdr *ip6 = NULL;
         struct iphdr *ip4 = NULL;
+        struct sec_path *sp;
         void *daddr;
         __be32 spi;
         u8 *c_hdr;
@@ -587,12 +588,12 @@ void ixgbevf_ipsec_rx(struct ixgbevf_ring *rx_ring,
         if (unlikely(!xs))
                 return;
 
-        skb->sp = secpath_dup(skb->sp);
-        if (unlikely(!skb->sp))
+        sp = secpath_set(skb);
+        if (unlikely(!sp))
                 return;
 
-        skb->sp->xvec[skb->sp->len++] = xs;
-        skb->sp->olen++;
+        sp->xvec[sp->len++] = xs;
+        sp->olen++;
         xo = xfrm_offload(skb);
         xo->flags = CRYPTO_DONE;
         xo->status = CRYPTO_SUCCESS;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.c
index f6717c287ff4..53608afd39b6 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.c
@@ -307,10 +307,11 @@ mlx5e_ipsec_build_sp(struct net_device *netdev, struct sk_buff *skb,
         struct mlx5e_priv *priv = netdev_priv(netdev);
         struct xfrm_offload *xo;
         struct xfrm_state *xs;
+        struct sec_path *sp;
         u32 sa_handle;
 
-        skb->sp = secpath_dup(skb->sp);
-        if (unlikely(!skb->sp)) {
+        sp = secpath_set(skb);
+        if (unlikely(!sp)) {
                 atomic64_inc(&priv->ipsec->sw_stats.ipsec_rx_drop_sp_alloc);
                 return NULL;
         }
@@ -322,8 +323,9 @@ mlx5e_ipsec_build_sp(struct net_device *netdev, struct sk_buff *skb,
                 return NULL;
         }
 
-        skb->sp->xvec[skb->sp->len++] = xs;
-        skb->sp->olen++;
+        sp = skb_sec_path(skb);
+        sp->xvec[sp->len++] = xs;
+        sp->olen++;
 
         xo = xfrm_offload(skb);
         xo->flags = CRYPTO_DONE;
diff --git a/net/xfrm/Kconfig b/net/xfrm/Kconfig
index 140270a13d54..5d43aaa17027 100644
--- a/net/xfrm/Kconfig
+++ b/net/xfrm/Kconfig
@@ -5,6 +5,7 @@ config XFRM
        bool
        depends on NET
        select GRO_CELLS
+       select SKB_EXTENSIONS
 
 config XFRM_OFFLOAD
        bool
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index 4ae87c5ce2e3..757c4d11983b 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -218,19 +218,16 @@ int xfrm_output(struct sock *sk, struct sk_buff *skb)
         if (xfrm_dev_offload_ok(skb, x)) {
                 struct sec_path *sp;
 
-                sp = secpath_dup(skb->sp);
+                sp = secpath_set(skb);
                 if (!sp) {
                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
                         kfree_skb(skb);
                         return -ENOMEM;
                 }
-                if (skb->sp)
-                        secpath_put(skb->sp);
-                skb->sp = sp;
                 skb->encapsulation = 1;
 
                 sp->olen++;
-                sp->xvec[skb->sp->len++] = x;
+                sp->xvec[sp->len++] = x;
                 xfrm_state_hold(x);
 
                 if (skb_is_gso(skb)) {