Add offload capability for performing protocol specific flow dissection
(either by EtherType or IP protocol).
Specifically:
- Add flow_dissect to offload callbacks
- Move flow_dissect_ret enum to flow_dissector.h, cleanup names and add a
couple of values
- Unify handling of functions that return flow_dissect_ret enum
- In __skb_flow_dissect, add default case for switch(proto) as well as
switch(ip_proto) that looks up and calls protocol specific flow
dissection
Signed-off-by: Tom Herbert <t...@quantonium.net>
---
include/linux/netdevice.h | 27 ++++++++++++++++++
include/net/flow_dissector.h | 1 +
net/core/dev.c | 65 ++++++++++++++++++++++++++++++++++++++++++++
net/core/flow_dissector.c | 16 +++++++++--
net/ipv4/route.c | 4 ++-
5 files changed, 110 insertions(+), 3 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 06b173200e23..f186b6ab480a 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2207,12 +2207,25 @@ struct offload_callbacks {
struct sk_buff **(*gro_receive)(struct sk_buff **head,
struct sk_buff *skb);
int (*gro_complete)(struct sk_buff *skb, int nhoff);
+ enum flow_dissect_ret (*flow_dissect)(struct sk_buff *skb,
+ struct flow_dissector_key_control *key_control,
+ struct flow_dissector *flow_dissector,
+ void *target_container, void *data,
+ __be16 *p_proto, u8 *p_ip_proto, int *p_nhoff,
+ int *p_hlen, unsigned int flags);
};
struct packet_offload {
__be16 type; /* This is really htons(ether_type). */
u16 priority;
struct offload_callbacks callbacks;
+ enum flow_dissect_ret (*proto_flow_dissect)(struct sk_buff *skb,
+ u8 proto,
+ struct flow_dissector_key_control *key_control,
+ struct flow_dissector *flow_dissector,
+ void *target_container, void *data,
+ __be16 *p_proto, u8 *p_ip_proto, int *p_nhoff,
+ int *p_hlen, unsigned int flags);
struct list_head list;
};
@@ -3252,6 +3265,20 @@ struct sk_buff *napi_get_frags(struct napi_struct *napi);
gro_result_t napi_gro_frags(struct napi_struct *napi);
struct packet_offload *gro_find_receive_by_type(__be16 type);
struct packet_offload *gro_find_complete_by_type(__be16 type);
+enum flow_dissect_ret flow_dissect_by_type(struct sk_buff *skb,
+ __be16 type,
+ struct flow_dissector_key_control *key_control,
+ struct flow_dissector *flow_dissector,
+ void *target_container, void *data,
+ __be16 *p_proto, u8 *p_ip_proto, int *p_nhoff,
+ int *p_hlen, unsigned int flags);
+enum flow_dissect_ret flow_dissect_by_type_proto(struct sk_buff *skb,
+ __be16 type, u8 proto,
+ struct flow_dissector_key_control *key_control,
+ struct flow_dissector *flow_dissector,
+ void *target_container, void *data,
+ __be16 *p_proto, u8 *p_ip_proto, int *p_nhoff,
+ int *p_hlen, unsigned int flags);
static inline void napi_free_frags(struct napi_struct *napi)
{
diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
index fc3dce730a6b..ad75bbfd1c9c 100644
--- a/include/net/flow_dissector.h
+++ b/include/net/flow_dissector.h
@@ -213,6 +213,7 @@ enum flow_dissector_key_id {
#define FLOW_DISSECTOR_F_STOP_AT_L3 BIT(1)
#define FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL BIT(2)
#define FLOW_DISSECTOR_F_STOP_AT_ENCAP BIT(3)
+#define FLOW_DISSECTOR_F_STOP_AT_L4 BIT(4)
struct flow_dissector_key {
enum flow_dissector_key_id key_id;
diff --git a/net/core/dev.c b/net/core/dev.c
index e350c768d4b5..f3cd884bd04b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -104,6 +104,7 @@
#include <linux/stat.h>
#include <net/dst.h>
#include <net/dst_metadata.h>
+#include <net/flow_dissector.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>
#include <net/checksum.h>
@@ -4907,6 +4908,70 @@ struct packet_offload *gro_find_complete_by_type(__be16
type)
}
EXPORT_SYMBOL(gro_find_complete_by_type);
+enum flow_dissect_ret flow_dissect_by_type(struct sk_buff *skb,
+ __be16 type,
+ struct flow_dissector_key_control *key_control,
+ struct flow_dissector *flow_dissector,
+ void *target_container, void *data,
+ __be16 *p_proto, u8 *p_ip_proto, int *p_nhoff,
+ int *p_hlen, unsigned int flags)
+{
+ enum flow_dissect_ret ret = FLOW_DISSECT_RET_CONTINUE;
+ struct list_head *offload_head = &offload_base;
+ struct packet_offload *ptype;
+
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(ptype, offload_head, list) {
+ if (ptype->type != type || !ptype->callbacks.flow_dissect)
+ continue;
+ ret = ptype->callbacks.flow_dissect(skb, key_control,
+ flow_dissector,
+ target_container,
+ data, p_proto,
+ p_ip_proto, p_nhoff,
+ p_hlen, flags);
+ break;
+ }
+
+ rcu_read_unlock();
+
+ return ret;
+}
+EXPORT_SYMBOL(flow_dissect_by_type);
+
+enum flow_dissect_ret flow_dissect_by_type_proto(struct sk_buff *skb,
+ __be16 type, u8 proto,
+ struct flow_dissector_key_control *key_control,
+ struct flow_dissector *flow_dissector,
+ void *target_container, void *data,
+ __be16 *p_proto, u8 *p_ip_proto, int *p_nhoff,
+ int *p_hlen, unsigned int flags)
+{
+ enum flow_dissect_ret ret = FLOW_DISSECT_RET_CONTINUE;
+ struct list_head *offload_head = &offload_base;
+ struct packet_offload *ptype;
+
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(ptype, offload_head, list) {
+ if (ptype->type != type || !ptype->proto_flow_dissect)
+ continue;
+ ret = ptype->proto_flow_dissect(skb, proto, key_control,
+ flow_dissector,
+ target_container,
+ data, p_proto,
+ p_ip_proto, p_nhoff,
+ p_hlen, flags);
+ break;
+ }
+
+ rcu_read_unlock();
+
+ return ret;
+}
+EXPORT_SYMBOL(flow_dissect_by_type_proto);
+
static void napi_skb_free_stolen_head(struct sk_buff *skb)
{
skb_dst_drop(skb);
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index c15b41f96cbe..84b8eb1f6664 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -9,6 +9,7 @@
#include <net/ipv6.h>
#include <net/gre.h>
#include <net/pptp.h>
+#include <net/protocol.h>
#include <linux/igmp.h>
#include <linux/icmp.h>
#include <linux/sctp.h>
@@ -721,7 +722,11 @@ bool __skb_flow_dissect(struct sk_buff *skb,
break;
default:
- fdret = FLOW_DISSECT_RET_OUT_BAD;
+ fdret = flow_dissect_by_type(skb, proto, key_control,
+ flow_dissector,
+ target_container,
+ data, &proto, &ip_proto, &nhoff,
+ &hlen, flags);
break;
}
@@ -838,6 +843,12 @@ bool __skb_flow_dissect(struct sk_buff *skb,
break;
default:
+ fdret = flow_dissect_by_type_proto(skb, proto,
+ ip_proto, key_control,
+ flow_dissector,
+ target_container,
+ data, &proto, &ip_proto, &nhoff,
+ &hlen, flags);
break;
}
@@ -1022,7 +1033,8 @@ static inline u32 ___skb_get_hash(struct sk_buff *skb,
struct flow_keys *keys, u32 keyval)
{
skb_flow_dissect_flow_keys(skb, keys,
- FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
+ FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL |
+ FLOW_DISSECTOR_F_STOP_AT_L4);
return __flow_hash_from_keys(keys, keyval);
}
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 94c5b81d8f2b..69d6ce7dfa18 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1811,7 +1811,9 @@ int fib_multipath_hash(const struct fib_info *fi, const
struct flowi4 *fl4,
case 1:
/* skb is currently provided only when forwarding */
if (skb) {
- unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
+ unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP |
+ FLOW_DISSECTOR_F_STOP_AT_L4;
+;
struct flow_keys keys;
/* short-circuit if we already have L4 hash present */
--
2.11.0
