This patch performs flow dissection for GUE and FOU. This is an
optional feature on the receiver and is set by FOU_ATTR_DEEP_HASH
netlink configuration. When enable the UDP socket flow_dissect
function is set to fou_flow_dissect or gue_flow_dissect as
appropriate. These functions return FLOW_DIS_RET_IPPROTO and
set ip protocol argument. In the case of GUE the header is
parsed to find the protocol number.
Signed-off-by: Tom Herbert <t...@herbertland.com>
---
include/uapi/linux/fou.h | 1 +
net/ipv4/fou.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 68 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/fou.h b/include/uapi/linux/fou.h
index d2947c5..2c837eb 100644
--- a/include/uapi/linux/fou.h
+++ b/include/uapi/linux/fou.h
@@ -15,6 +15,7 @@ enum {
FOU_ATTR_IPPROTO, /* u8 */
FOU_ATTR_TYPE, /* u8 */
FOU_ATTR_REMCSUM_NOPARTIAL, /* flag */
+ FOU_ATTR_DEEP_HASH, /* flag */
__FOU_ATTR_MAX,
};
diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c
index cf50f7e..95ac5a8 100644
--- a/net/ipv4/fou.c
+++ b/net/ipv4/fou.c
@@ -27,7 +27,8 @@ struct fou {
struct rcu_head rcu;
};
-#define FOU_F_REMCSUM_NOPARTIAL BIT(0)
+#define FOU_F_REMCSUM_NOPARTIAL BIT(0)
+#define FOU_F_DEEP_HASH BIT(1)
struct fou_cfg {
u16 type;
@@ -281,6 +282,16 @@ static int fou_gro_complete(struct sock *sk, struct
sk_buff *skb,
return err;
}
+static int fou_flow_dissect(struct sock *sk, const struct sk_buff *skb,
+ void *data, int hlen, int *nhoff, u8 *ip_proto,
+ __be16 *proto)
+{
+ *ip_proto = fou_from_sock(sk)->protocol;
+ *nhoff += sizeof(struct udphdr);
+
+ return FLOW_DIS_RET_IPPROTO;
+}
+
static struct guehdr *gue_gro_remcsum(struct sk_buff *skb, unsigned int off,
struct guehdr *guehdr, void *data,
size_t hdrlen, struct gro_remcsum *grc,
@@ -498,6 +509,48 @@ static int gue_gro_complete(struct sock *sk, struct
sk_buff *skb, int nhoff)
return err;
}
+static int gue_flow_dissect(struct sock *sk, const struct sk_buff *skb,
+ void *data, int hlen, int *nhoff, u8 *ip_proto,
+ __be16 *proto)
+{
+ struct guehdr _hdr, *hdr;
+
+ hdr = __skb_header_pointer(skb, *nhoff + sizeof(struct udphdr),
+ sizeof(_hdr), data, hlen, &_hdr);
+ if (!hdr)
+ return FLOW_DIS_RET_BAD;
+
+ switch (hdr->version) {
+ case 0: /* Full GUE header present */
+ if (hdr->control)
+ return FLOW_DIS_RET_PASS;
+
+ *nhoff += sizeof(struct udphdr) + sizeof(_hdr) +
+ (hdr->hlen << 2);
+ *ip_proto = hdr->proto_ctype;
+
+ return FLOW_DIS_RET_IPPROTO;
+ case 1:
+ /* Direct encasulation of IPv4 or IPv6 */
+
+ switch (((struct iphdr *)hdr)->version) {
+ case 4:
+ *nhoff += sizeof(struct udphdr);
+ *ip_proto = IPPROTO_IPIP;
+ return FLOW_DIS_RET_IPPROTO;
+ case 6:
+ *nhoff += sizeof(struct udphdr);
+ *ip_proto = IPPROTO_IPV6;
+ return FLOW_DIS_RET_IPPROTO;
+ default:
+ return FLOW_DIS_RET_PASS;
+ }
+
+ default:
+ return FLOW_DIS_RET_PASS;
+ }
+}
+
static int fou_add_to_port_list(struct net *net, struct fou *fou)
{
struct fou_net *fn = net_generic(net, fou_net_id);
@@ -568,12 +621,16 @@ static int fou_create(struct net *net, struct fou_cfg
*cfg,
tunnel_cfg.encap_rcv = fou_udp_recv;
tunnel_cfg.gro_receive = fou_gro_receive;
tunnel_cfg.gro_complete = fou_gro_complete;
+ if (cfg->flags & FOU_F_DEEP_HASH)
+ tunnel_cfg.flow_dissect = fou_flow_dissect;
fou->protocol = cfg->protocol;
break;
case FOU_ENCAP_GUE:
tunnel_cfg.encap_rcv = gue_udp_recv;
tunnel_cfg.gro_receive = gue_gro_receive;
tunnel_cfg.gro_complete = gue_gro_complete;
+ if (cfg->flags & FOU_F_DEEP_HASH)
+ tunnel_cfg.flow_dissect = gue_flow_dissect;
break;
default:
err = -EINVAL;
@@ -637,6 +694,7 @@ static const struct nla_policy fou_nl_policy[FOU_ATTR_MAX +
1] = {
[FOU_ATTR_IPPROTO] = { .type = NLA_U8, },
[FOU_ATTR_TYPE] = { .type = NLA_U8, },
[FOU_ATTR_REMCSUM_NOPARTIAL] = { .type = NLA_FLAG, },
+ [FOU_ATTR_DEEP_HASH] = { .type = NLA_FLAG },
};
static int parse_nl_config(struct genl_info *info,
@@ -677,6 +735,9 @@ static int parse_nl_config(struct genl_info *info,
if (info->attrs[FOU_ATTR_REMCSUM_NOPARTIAL])
cfg->flags |= FOU_F_REMCSUM_NOPARTIAL;
+ if (info->attrs[FOU_ATTR_DEEP_HASH])
+ cfg->flags |= FOU_F_DEEP_HASH;
+
return 0;
}
@@ -717,6 +778,11 @@ static int fou_fill_info(struct fou *fou, struct sk_buff
*msg)
if (fou->flags & FOU_F_REMCSUM_NOPARTIAL)
if (nla_put_flag(msg, FOU_ATTR_REMCSUM_NOPARTIAL))
return -1;
+
+ if (fou->flags & FOU_F_DEEP_HASH)
+ if (nla_put_flag(msg, FOU_ATTR_DEEP_HASH))
+ return -1;
+
return 0;
}
--
2.9.3
