commit 35d2856b4693e8de5d616307b56cef296b839157
author Martin Willi <martin@strongswan.org> Wed Dec 08 04:37:49 2010 +0000
committer David S. Miller <davem@davemloft.net> Fri Dec 10 14:43:58 2010 -0800
tree ad267bf9f3312b2d64bec8b4912178577a8cb71e
parent 957fca95e3521e471aac4c2e4cfbc21f399bdd84

xfrm: Add Traffic Flow Confidentiality padding XFRM attribute

The XFRMA_TFCPAD attribute for XFRM state installation configures
Traffic Flow Confidentiality by padding ESP packets to a specified
length.

Signed-off-by: Martin Willi <martin@strongswan.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/xfrm/xfrm_user.c

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 8bae6b2..8eb8895 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -148,7 +148,8 @@
 		     !attrs[XFRMA_ALG_AUTH_TRUNC]) ||
 		    attrs[XFRMA_ALG_AEAD]	||
 		    attrs[XFRMA_ALG_CRYPT]	||
-		    attrs[XFRMA_ALG_COMP])
+		    attrs[XFRMA_ALG_COMP]	||
+		    attrs[XFRMA_TFCPAD])
 			goto out;
 		break;
 
@@ -165,6 +166,9 @@
 		     attrs[XFRMA_ALG_CRYPT]) &&
 		    attrs[XFRMA_ALG_AEAD])
 			goto out;
+		if (attrs[XFRMA_TFCPAD] &&
+		    p->mode != XFRM_MODE_TUNNEL)
+			goto out;
 		break;
 
 	case IPPROTO_COMP:
@@ -172,7 +176,8 @@
 		    attrs[XFRMA_ALG_AEAD]	||
 		    attrs[XFRMA_ALG_AUTH]	||
 		    attrs[XFRMA_ALG_AUTH_TRUNC]	||
-		    attrs[XFRMA_ALG_CRYPT])
+		    attrs[XFRMA_ALG_CRYPT]	||
+		    attrs[XFRMA_TFCPAD])
 			goto out;
 		break;
 
@@ -186,6 +191,7 @@
 		    attrs[XFRMA_ALG_CRYPT]	||
 		    attrs[XFRMA_ENCAP]		||
 		    attrs[XFRMA_SEC_CTX]	||
+		    attrs[XFRMA_TFCPAD]		||
 		    !attrs[XFRMA_COADDR])
 			goto out;
 		break;
@@ -439,6 +445,9 @@
 			goto error;
 	}
 
+	if (attrs[XFRMA_TFCPAD])
+		x->tfcpad = nla_get_u32(attrs[XFRMA_TFCPAD]);
+
 	if (attrs[XFRMA_COADDR]) {
 		x->coaddr = kmemdup(nla_data(attrs[XFRMA_COADDR]),
 				    sizeof(*x->coaddr), GFP_KERNEL);
@@ -688,6 +697,9 @@
 	if (x->encap)
 		NLA_PUT(skb, XFRMA_ENCAP, sizeof(*x->encap), x->encap);
 
+	if (x->tfcpad)
+		NLA_PUT_U32(skb, XFRMA_TFCPAD, x->tfcpad);
+
 	if (xfrm_mark_put(skb, &x->mark))
 		goto nla_put_failure;
 
@@ -2122,6 +2134,7 @@
 	[XFRMA_MIGRATE]		= { .len = sizeof(struct xfrm_user_migrate) },
 	[XFRMA_KMADDRESS]	= { .len = sizeof(struct xfrm_user_kmaddress) },
 	[XFRMA_MARK]		= { .len = sizeof(struct xfrm_mark) },
+	[XFRMA_TFCPAD]		= { .type = NLA_U32 },
 };
 
 static struct xfrm_link {
@@ -2301,6 +2314,8 @@
 		l += nla_total_size(sizeof(*x->calg));
 	if (x->encap)
 		l += nla_total_size(sizeof(*x->encap));
+	if (x->tfcpad)
+		l += nla_total_size(sizeof(x->tfcpad));
 	if (x->security)
 		l += nla_total_size(sizeof(struct xfrm_user_sec_ctx) +
 				    x->security->ctx_len);