xfrm: remove xmit indirection from xfrm_mode

There are only two versions (tunnel and transport). The ip/ipv6 versions
are only differ in sizeof(iphdr) vs ipv6hdr.

Place this in the core and use x->outer_mode->encap type to call the
correct adjustment helper.

Before:
   text   data    bss     dec      filename
15730311  6937008 4046908 26714227 vmlinux

After:
15730428  6937008 4046908 26714344 vmlinux

(about 117 byte increase)

v2: use family from x->outer_mode, not inner

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

6 files changed, 56 insertions, 60 deletions

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 01e7e9c0e8a9..07966a27e4a4 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -454,11 +454,6 @@ struct xfrm_mode {
 	 */
 	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;
 	u8 encap;
diff --git a/net/ipv4/xfrm4_mode_transport.c b/net/ipv4/xfrm4_mode_transport.c
index 6f8cf09ff0ef..d4b34bb2de00 100644
--- a/net/ipv4/xfrm4_mode_transport.c
+++ b/net/ipv4/xfrm4_mode_transport.c
@@ -30,22 +30,8 @@ static struct sk_buff *xfrm4_transport_gso_segment(struct xfrm_state *x,
 	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 = {
 	.gso_segment = xfrm4_transport_gso_segment,
-	.xmit = xfrm4_transport_xmit,
 	.owner = THIS_MODULE,
 	.encap = XFRM_MODE_TRANSPORT,
 	.family = AF_INET,
diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c
index 823bc54b47de..8bd5112b3ee3 100644
--- a/net/ipv4/xfrm4_mode_tunnel.c
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -109,23 +109,10 @@ static struct sk_buff *xfrm4_mode_tunnel_gso_segment(struct xfrm_state *x,
 	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->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,
 	.output2 = xfrm4_mode_tunnel_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 1e7165a8481a..6a72ff39bc05 100644
--- a/net/ipv6/xfrm6_mode_transport.c
+++ b/net/ipv6/xfrm6_mode_transport.c
@@ -31,22 +31,8 @@ static struct sk_buff *xfrm4_transport_gso_segment(struct xfrm_state *x,
 	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 = {
 	.gso_segment = xfrm4_transport_gso_segment,
-	.xmit = xfrm6_transport_xmit,
 	.owner = THIS_MODULE,
 	.encap = XFRM_MODE_TRANSPORT,
 	.family = AF_INET6,
diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index e1a129524dde..7450dd87f27d 100644
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -109,22 +109,10 @@ static struct sk_buff *xfrm6_mode_tunnel_gso_segment(struct xfrm_state *x,
 	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->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,
 	.output2 = xfrm6_mode_tunnel_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,
diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c
index e437b60fba51..a20f376fe71f 100644
--- a/net/xfrm/xfrm_device.c
+++ b/net/xfrm/xfrm_device.c
@@ -23,6 +23,60 @@
 #include <linux/notifier.h>
 
 #ifdef CONFIG_XFRM_OFFLOAD
+static void __xfrm_transport_prep(struct xfrm_state *x, struct sk_buff *skb,
+				  unsigned int hsize)
+{
+	struct xfrm_offload *xo = xfrm_offload(skb);
+
+	skb_reset_mac_len(skb);
+	pskb_pull(skb, skb->mac_len + hsize + x->props.header_len);
+
+	if (xo->flags & XFRM_GSO_SEGMENT) {
+		skb_reset_transport_header(skb);
+		skb->transport_header -= x->props.header_len;
+	}
+}
+
+static void __xfrm_mode_tunnel_prep(struct xfrm_state *x, struct sk_buff *skb,
+				    unsigned int hsize)
+
+{
+	struct xfrm_offload *xo = xfrm_offload(skb);
+
+	if (xo->flags & XFRM_GSO_SEGMENT)
+		skb->transport_header = skb->network_header + hsize;
+
+	skb_reset_mac_len(skb);
+	pskb_pull(skb, skb->mac_len + x->props.header_len);
+}
+
+/* Adjust pointers into the packet when IPsec is done at layer2 */
+static void xfrm_outer_mode_prep(struct xfrm_state *x, struct sk_buff *skb)
+{
+	switch (x->outer_mode->encap) {
+	case XFRM_MODE_TUNNEL:
+		if (x->outer_mode->family == AF_INET)
+			return __xfrm_mode_tunnel_prep(x, skb,
+						       sizeof(struct iphdr));
+		if (x->outer_mode->family == AF_INET6)
+			return __xfrm_mode_tunnel_prep(x, skb,
+						       sizeof(struct ipv6hdr));
+		break;
+	case XFRM_MODE_TRANSPORT:
+		if (x->outer_mode->family == AF_INET)
+			return __xfrm_transport_prep(x, skb,
+						     sizeof(struct iphdr));
+		if (x->outer_mode->family == AF_INET6)
+			return __xfrm_transport_prep(x, skb,
+						     sizeof(struct ipv6hdr));
+		break;
+	case XFRM_MODE_ROUTEOPTIMIZATION:
+	case XFRM_MODE_IN_TRIGGER:
+	case XFRM_MODE_BEET:
+		break;
+	}
+}
+
 struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features, bool *again)
 {
 	int err;
@@ -79,7 +133,7 @@ struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t featur
 
 	if (!skb->next) {
 		esp_features |= skb->dev->gso_partial_features;
-		x->outer_mode->xmit(x, skb);
+		xfrm_outer_mode_prep(x, skb);
 
 		xo->flags |= XFRM_DEV_RESUME;
 
@@ -109,7 +163,7 @@ struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t featur
 		xo = xfrm_offload(skb2);
 		xo->flags |= XFRM_DEV_RESUME;
 
-		x->outer_mode->xmit(x, skb2);
+		xfrm_outer_mode_prep(x, skb2);
 
 		err = x->type_offload->xmit(x, skb2, esp_features);
 		if (!err) {