xfrm: Add mode handlers for IPsec on layer 2

This patch adds a gso_segment and xmit callback for the
xfrm_mode and implement these functions for tunnel and
transport mode.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index ac984da..54515d9 100644 (file)
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -444,6 +444,16 @@ struct xfrm_mode {
         */
        int (*output)(struct xfrm_state *x, struct sk_buff *skb);
 
+       /*
+        * Adjust pointers into the packet and do GSO segmentation.
+        */
+       struct sk_buff *(*gso_segment)(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features);
+
+       /*
+        * Adjust pointers into the packet when IPsec is done at layer2.
+        */
+       void (*xmit)(struct xfrm_state *x, struct sk_buff *skb);
+
        struct xfrm_state_afinfo *afinfo;
        struct module *owner;
        unsigned int encap;

diff --git a/net/ipv4/xfrm4_mode_transport.c b/net/ipv4/xfrm4_mode_transport.c
index 4acc050..6c2411d 100644 (file)
--- a/net/ipv4/xfrm4_mode_transport.c
+++ b/net/ipv4/xfrm4_mode_transport.c
@@ -12,6 +12,7 @@
 #include <net/dst.h>
 #include <net/ip.h>
 #include <net/xfrm.h>
+#include <net/protocol.h>
 
 /* Add encapsulation header.
  *
@@ -56,9 +57,40 @@ static int xfrm4_transport_input(struct xfrm_state *x, struct sk_buff *skb)
        return 0;
 }
 
+static struct sk_buff *xfrm4_transport_gso_segment(struct xfrm_state *x,
+                                                  struct sk_buff *skb,
+                                                  netdev_features_t features)
+{
+       const struct net_offload *ops;
+       struct sk_buff *segs = ERR_PTR(-EINVAL);
+       struct xfrm_offload *xo = xfrm_offload(skb);
+
+       skb->transport_header += x->props.header_len;
+       ops = rcu_dereference(inet_offloads[xo->proto]);
+       if (likely(ops && ops->callbacks.gso_segment))
+               segs = ops->callbacks.gso_segment(skb, features);
+
+       return segs;
+}
+
+static void xfrm4_transport_xmit(struct xfrm_state *x, struct sk_buff *skb)
+{
+       struct xfrm_offload *xo = xfrm_offload(skb);
+
+       skb_reset_mac_len(skb);
+       pskb_pull(skb, skb->mac_len + sizeof(struct iphdr) + x->props.header_len);
+
+       if (xo->flags & XFRM_GSO_SEGMENT) {
+                skb_reset_transport_header(skb);
+                skb->transport_header -= x->props.header_len;
+       }
+}
+
 static struct xfrm_mode xfrm4_transport_mode = {
        .input = xfrm4_transport_input,
        .output = xfrm4_transport_output,
+       .gso_segment = xfrm4_transport_gso_segment,
+       .xmit = xfrm4_transport_xmit,
        .owner = THIS_MODULE,
        .encap = XFRM_MODE_TRANSPORT,
 };

diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c
index 35feda6..d3f2434 100644 (file)
--- a/net/ipv4/xfrm4_mode_tunnel.c
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -96,11 +96,36 @@ out:
        return err;
 }
 
+static struct sk_buff *xfrm4_mode_tunnel_gso_segment(struct xfrm_state *x,
+                                                    struct sk_buff *skb,
+                                                    netdev_features_t features)
+{
+       __skb_push(skb, skb->mac_len);
+       return skb_mac_gso_segment(skb, features);
+
+}
+
+static void xfrm4_mode_tunnel_xmit(struct xfrm_state *x, struct sk_buff *skb)
+{
+       struct xfrm_offload *xo = xfrm_offload(skb);
+
+       if (xo->flags & XFRM_GSO_SEGMENT) {
+               skb->network_header = skb->network_header - x->props.header_len;
+               skb->transport_header = skb->network_header +
+                                       sizeof(struct iphdr);
+       }
+
+       skb_reset_mac_len(skb);
+       pskb_pull(skb, skb->mac_len + x->props.header_len);
+}
+
 static struct xfrm_mode xfrm4_tunnel_mode = {
        .input2 = xfrm4_mode_tunnel_input,
        .input = xfrm_prepare_input,
        .output2 = xfrm4_mode_tunnel_output,
        .output = xfrm4_prepare_output,
+       .gso_segment = xfrm4_mode_tunnel_gso_segment,
+       .xmit = xfrm4_mode_tunnel_xmit,
        .owner = THIS_MODULE,
        .encap = XFRM_MODE_TUNNEL,
        .flags = XFRM_MODE_FLAG_TUNNEL,

diff --git a/net/ipv6/xfrm6_mode_transport.c b/net/ipv6/xfrm6_mode_transport.c
index 4439ee4..eb9b36b 100644 (file)
--- a/net/ipv6/xfrm6_mode_transport.c
+++ b/net/ipv6/xfrm6_mode_transport.c
@@ -13,6 +13,7 @@
 #include <net/dst.h>
 #include <net/ipv6.h>
 #include <net/xfrm.h>
+#include <net/protocol.h>
 
 /* Add encapsulation header.
  *
@@ -61,9 +62,41 @@ static int xfrm6_transport_input(struct xfrm_state *x, struct sk_buff *skb)
        return 0;
 }
 
+static struct sk_buff *xfrm4_transport_gso_segment(struct xfrm_state *x,
+                                                  struct sk_buff *skb,
+                                                  netdev_features_t features)
+{
+       const struct net_offload *ops;
+       struct sk_buff *segs = ERR_PTR(-EINVAL);
+       struct xfrm_offload *xo = xfrm_offload(skb);
+
+       skb->transport_header += x->props.header_len;
+       ops = rcu_dereference(inet6_offloads[xo->proto]);
+       if (likely(ops && ops->callbacks.gso_segment))
+               segs = ops->callbacks.gso_segment(skb, features);
+
+       return segs;
+}
+
+static void xfrm6_transport_xmit(struct xfrm_state *x, struct sk_buff *skb)
+{
+       struct xfrm_offload *xo = xfrm_offload(skb);
+
+       skb_reset_mac_len(skb);
+       pskb_pull(skb, skb->mac_len + sizeof(struct ipv6hdr) + x->props.header_len);
+
+       if (xo->flags & XFRM_GSO_SEGMENT) {
+                skb_reset_transport_header(skb);
+                skb->transport_header -= x->props.header_len;
+       }
+}
+
+
 static struct xfrm_mode xfrm6_transport_mode = {
        .input = xfrm6_transport_input,
        .output = xfrm6_transport_output,
+       .gso_segment = xfrm4_transport_gso_segment,
+       .xmit = xfrm6_transport_xmit,
        .owner = THIS_MODULE,
        .encap = XFRM_MODE_TRANSPORT,
 };

diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index 372855e..19a60fc 100644 (file)
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -96,11 +96,35 @@ out:
        return err;
 }
 
+static struct sk_buff *xfrm6_mode_tunnel_gso_segment(struct xfrm_state *x,
+                                                    struct sk_buff *skb,
+                                                    netdev_features_t features)
+{
+       __skb_push(skb, skb->mac_len);
+       return skb_mac_gso_segment(skb, features);
+
+}
+
+static void xfrm6_mode_tunnel_xmit(struct xfrm_state *x, struct sk_buff *skb)
+{
+       struct xfrm_offload *xo = xfrm_offload(skb);
+
+       if (xo->flags & XFRM_GSO_SEGMENT) {
+               skb->network_header = skb->network_header - x->props.header_len;
+               skb->transport_header = skb->network_header + sizeof(struct ipv6hdr);
+       }
+
+       skb_reset_mac_len(skb);
+       pskb_pull(skb, skb->mac_len + x->props.header_len);
+}
+
 static struct xfrm_mode xfrm6_tunnel_mode = {
        .input2 = xfrm6_mode_tunnel_input,
        .input = xfrm_prepare_input,
        .output2 = xfrm6_mode_tunnel_output,
        .output = xfrm6_prepare_output,
+       .gso_segment = xfrm6_mode_tunnel_gso_segment,
+       .xmit = xfrm6_mode_tunnel_xmit,
        .owner = THIS_MODULE,
        .encap = XFRM_MODE_TUNNEL,
        .flags = XFRM_MODE_FLAG_TUNNEL,