xfrm: remove get_mtu indirection from xfrm_type

esp4_get_mtu and esp6_get_mtu are exactly the same, the only difference
is a single sizeof() (ipv4 vs. ipv6 header).

Merge both into xfrm_state_mtu() and remove the indirection.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

1 files changed, 1 insertions, 26 deletions

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index c06562aded11..5c967764041f 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -33,8 +33,6 @@ struct esp_output_extra {
 
 #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
 
-static u32 esp4_get_mtu(struct xfrm_state *x, int mtu);
-
 /*
  * Allocate an AEAD request structure with extra space for SG and IV.
  *
@@ -506,7 +504,7 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
 		struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
 		u32 padto;
 
-		padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached));
+		padto = min(x->tfcpad, xfrm_state_mtu(x, dst->child_mtu_cached));
 		if (skb->len < padto)
 			esp.tfclen = padto - skb->len;
 	}
@@ -788,28 +786,6 @@ out:
 	return err;
 }
 
-static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
-{
-	struct crypto_aead *aead = x->data;
-	u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
-	unsigned int net_adj;
-
-	switch (x->props.mode) {
-	case XFRM_MODE_TRANSPORT:
-	case XFRM_MODE_BEET:
-		net_adj = sizeof(struct iphdr);
-		break;
-	case XFRM_MODE_TUNNEL:
-		net_adj = 0;
-		break;
-	default:
-		BUG();
-	}
-
-	return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
-		 net_adj) & ~(blksize - 1)) + net_adj - 2;
-}
-
 static int esp4_err(struct sk_buff *skb, u32 info)
 {
 	struct net *net = dev_net(skb->dev);
@@ -1035,7 +1011,6 @@ static const struct xfrm_type esp_type =
 	.flags		= XFRM_TYPE_REPLAY_PROT,
 	.init_state	= esp_init_state,
 	.destructor	= esp_destroy,
-	.get_mtu	= esp4_get_mtu,
 	.input		= esp_input,
 	.output		= esp_output,
 };