ila: add checksum neutral ILA translations

Support checksum neutral ILA as described in the ILA draft. The low
order 16 bits of the identifier are used to contain the checksum
adjustment value.

The csum-mode parameter is added to described checksum processing. There
are three values:
 - adjust transport checksum (previous behavior)
 - do checksum neutral mapping
 - do nothing

On output the csum-mode in the ila_params is checked and acted on. If
mode is checksum neutral mapping then to mapping and set C-bit.

On input, C-bit is checked. If it is set checksum-netural mapping is
done (regardless of csum-mode in ila params) and C-bit will be cleared.
If it is not set then action in csum-mode is taken.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 8 deletions

diff --git a/net/ipv6/ila/ila_xlat.c b/net/ipv6/ila/ila_xlat.c
index 2e6cb97aee19..a90e57229c6c 100644
--- a/net/ipv6/ila/ila_xlat.c
+++ b/net/ipv6/ila/ila_xlat.c
@@ -132,6 +132,7 @@ static struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = {
 	[ILA_ATTR_LOCATOR] = { .type = NLA_U64, },
 	[ILA_ATTR_LOCATOR_MATCH] = { .type = NLA_U64, },
 	[ILA_ATTR_IFINDEX] = { .type = NLA_U32, },
+	[ILA_ATTR_CSUM_MODE] = { .type = NLA_U8, },
 };
 
 static int parse_nl_config(struct genl_info *info,
@@ -147,6 +148,9 @@ static int parse_nl_config(struct genl_info *info,
 		xp->ip.locator_match.v64 = (__force __be64)nla_get_u64(
 			info->attrs[ILA_ATTR_LOCATOR_MATCH]);
 
+	if (info->attrs[ILA_ATTR_CSUM_MODE])
+		xp->ip.csum_mode = nla_get_u8(info->attrs[ILA_ATTR_CSUM_MODE]);
+
 	if (info->attrs[ILA_ATTR_IFINDEX])
 		xp->ifindex = nla_get_s32(info->attrs[ILA_ATTR_IFINDEX]);
 
@@ -249,14 +253,9 @@ static int ila_add_mapping(struct net *net, struct ila_xlat_params *xp)
 	if (!ila)
 		return -ENOMEM;
 
-	ila->xp = *xp;
+	ila_init_saved_csum(&xp->ip);
 
-	/* Precompute checksum difference for translation since we
-	 * know both the old identifier and the new one.
-	 */
-	ila->xp.ip.csum_diff = compute_csum_diff8(
-		(__be32 *)&xp->ip.locator_match,
-		(__be32 *)&xp->ip.locator);
+	ila->xp = *xp;
 
 	order = ila_order(ila);
 
@@ -408,7 +407,8 @@ static int ila_fill_info(struct ila_map *ila, struct sk_buff *msg)
 	    nla_put_u64_64bit(msg, ILA_ATTR_LOCATOR_MATCH,
 			      (__force u64)ila->xp.ip.locator_match.v64,
 			      ILA_ATTR_PAD) ||
-	    nla_put_s32(msg, ILA_ATTR_IFINDEX, ila->xp.ifindex))
+	    nla_put_s32(msg, ILA_ATTR_IFINDEX, ila->xp.ifindex) ||
+	    nla_put_u32(msg, ILA_ATTR_CSUM_MODE, ila->xp.ip.csum_mode))
 		return -1;
 
 	return 0;