[PATCH net-next 1/2] flow_dissector: add mpls support (v2)

Benjamin LaHaise
2017-04-22T20:54:03Z

Add support for parsing MPLS flows to the flow dissector in preparation for
adding MPLS match support to cls_flower.

Signed-off-by: Benjamin LaHaise <benjamin.lahaise@netronome.com>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Simon Horman <simon.horman@netronome.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Eric Dumazet <jhs@mojatatu.com>
Cc: Hadar Hen Zion <hadarh@mellanox.com>
Cc: Gao Feng <fgao@ikuai8.com>
---
include/linux/mpls.h | 5 +++++
include/net/flow_dissector.h | 8 ++++++++
net/core/flow_dissector.c | 25 ++++++++++++++++++++++---
3 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/include/linux/mpls.h b/include/linux/mpls.h
index 9999145..384fb22 100644
--- a/include/linux/mpls.h
+++ b/include/linux/mpls.h
@@ -3,4 +3,9 @@

#include <uapi/linux/mpls.h>

+#define MPLS_TTL_MASK (MPLS_LS_TTL_MASK >> MPLS_LS_TTL_SHIFT)
+#define MPLS_BOS_MASK (MPLS_LS_S_MASK >> MPLS_LS_S_SHIFT)
+#define MPLS_TC_MASK (MPLS_LS_TC_MASK >> MPLS_LS_TC_SHIFT)
+#define MPLS_LABEL_MASK (MPLS_LS_LABEL_MASK >> MPLS_LS_LABEL_SHIFT)
+
#endif /* _LINUX_MPLS_H */
diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
index ac97030..8d21d44 100644
--- a/include/net/flow_dissector.h
+++ b/include/net/flow_dissector.h
@@ -41,6 +41,13 @@ struct flow_dissector_key_vlan {
u16 padding;
};

+struct flow_dissector_key_mpls {
+ u32 mpls_ttl:8,
+ mpls_bos:1,
+ mpls_tc:3,
+ mpls_label:20;
+};
+
struct flow_dissector_key_keyid {
__be32 keyid;
};
@@ -169,6 +176,7 @@ enum flow_dissector_key_id {
FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
FLOW_DISSECTOR_KEY_ENC_CONTROL, /* struct flow_dissector_key_control */
FLOW_DISSECTOR_KEY_ENC_PORTS, /* struct flow_dissector_key_ports */
+ FLOW_DISSECTOR_KEY_MPLS, /* struct flow_dissector_key_mpls */

FLOW_DISSECTOR_KEY_MAX,
};
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index c9cf425..28d94bc 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -126,9 +126,11 @@ __skb_flow_dissect_mpls(const struct sk_buff *skb,
{
struct flow_dissector_key_keyid *key_keyid;
struct mpls_label *hdr, _hdr[2];
+ u32 entry, label;

if (!dissector_uses_key(flow_dissector,
- FLOW_DISSECTOR_KEY_MPLS_ENTROPY))
+ FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
+ !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
return FLOW_DISSECT_RET_OUT_GOOD;

hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
@@ -136,8 +138,25 @@ __skb_flow_dissect_mpls(const struct sk_buff *skb,
if (!hdr)
return FLOW_DISSECT_RET_OUT_BAD;

- if ((ntohl(hdr[0].entry) & MPLS_LS_LABEL_MASK) >>
- MPLS_LS_LABEL_SHIFT == MPLS_LABEL_ENTROPY) {
+ entry = ntohl(hdr[0].entry);
+ label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
+
+ if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
+ struct flow_dissector_key_mpls *key_mpls;
+
+ key_mpls = skb_flow_dissector_target(flow_dissector,
+ FLOW_DISSECTOR_KEY_MPLS,
+ target_container);
+ key_mpls->mpls_label = label;
+ key_mpls->mpls_ttl = (entry & MPLS_LS_TTL_MASK)
+ >> MPLS_LS_TTL_SHIFT;
+ key_mpls->mpls_tc = (entry & MPLS_LS_TC_MASK)
+ >> MPLS_LS_TC_SHIFT;
+ key_mpls->mpls_bos = (entry & MPLS_LS_S_MASK)
+ >> MPLS_LS_S_SHIFT;
+ }
+
+ if (label == MPLS_LABEL_ENTROPY) {
key_keyid = skb_flow_dissector_target(flow_dissector,
FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
target_container);
--
2.7.4