[PATCH v4 net-next 4/8] flow_dissector: Add protocol specific flow dissection offload
From: Tom Herbert <hidden>
Date: 2017-09-28 23:53:03
Subsystem:
networking drivers, networking [general], networking [ipv4/ipv6], the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
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 <redacted> --- 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