From f70ea018da0631e10c26a02f5a82d626ffef5bd7 Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Fri, 31 Jul 2015 16:52:10 -0700 Subject: [PATCH] net: Add functions to get skb->hash based on flow structures Add skb_get_hash_flowi6 and skb_get_hash_flowi4 which derive an sk_buff hash from flowi6 and flowi4 structures respectively. These functions can be called when creating a packet in the output path where the new sk_buff does not yet contain a fully formed packet that is parsable by flow dissector. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- include/linux/skbuff.h | 21 ++++++++++++++ net/core/flow_dissector.c | 58 ++++++++++++++++++++++++++++++++++++--- 2 files changed, 75 insertions(+), 4 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 648a2c241993..b7c1286e247d 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -37,6 +37,7 @@ #include #include #include +#include /* A. Checksumming of received packets by device. * @@ -945,6 +946,26 @@ static inline __u32 skb_get_hash(struct sk_buff *skb) return skb->hash; } +__u32 __skb_get_hash_flowi6(struct sk_buff *skb, struct flowi6 *fl6); + +static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, struct flowi6 *fl6) +{ + if (!skb->l4_hash && !skb->sw_hash) + __skb_get_hash_flowi6(skb, fl6); + + return skb->hash; +} + +__u32 __skb_get_hash_flowi4(struct sk_buff *skb, struct flowi4 *fl); + +static inline __u32 skb_get_hash_flowi4(struct sk_buff *skb, struct flowi4 *fl4) +{ + if (!skb->l4_hash && !skb->sw_hash) + __skb_get_hash_flowi4(skb, fl4); + + return skb->hash; +} + __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb); static inline __u32 skb_get_hash_raw(const struct sk_buff *skb) diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 2a834c6179b9..11e6540fa386 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -590,6 +590,15 @@ void make_flow_keys_digest(struct flow_keys_digest *digest, } EXPORT_SYMBOL(make_flow_keys_digest); +static inline void __skb_set_sw_hash(struct sk_buff *skb, u32 hash, + struct flow_keys *keys) +{ + if (keys->ports.ports) + skb->l4_hash = 1; + skb->sw_hash = 1; + skb->hash = hash; +} + /** * __skb_get_hash: calculate a flow hash * @skb: sk_buff to calculate flow hash from @@ -609,10 +618,8 @@ void __skb_get_hash(struct sk_buff *skb) hash = ___skb_get_hash(skb, &keys, hashrnd); if (!hash) return; - if (keys.ports.ports) - skb->l4_hash = 1; - skb->sw_hash = 1; - skb->hash = hash; + + __skb_set_sw_hash(skb, hash, &keys); } EXPORT_SYMBOL(__skb_get_hash); @@ -624,6 +631,49 @@ __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb) } EXPORT_SYMBOL(skb_get_hash_perturb); +__u32 __skb_get_hash_flowi6(struct sk_buff *skb, struct flowi6 *fl6) +{ + struct flow_keys keys; + + memset(&keys, 0, sizeof(keys)); + + memcpy(&keys.addrs.v6addrs.src, &fl6->saddr, + sizeof(keys.addrs.v6addrs.src)); + memcpy(&keys.addrs.v6addrs.dst, &fl6->daddr, + sizeof(keys.addrs.v6addrs.dst)); + keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; + keys.ports.src = fl6->fl6_sport; + keys.ports.dst = fl6->fl6_dport; + keys.keyid.keyid = fl6->fl6_gre_key; + keys.tags.flow_label = (__force u32)fl6->flowlabel; + keys.basic.ip_proto = fl6->flowi6_proto; + + __skb_set_sw_hash(skb, flow_hash_from_keys(&keys), &keys); + + return skb->hash; +} +EXPORT_SYMBOL(__skb_get_hash_flowi6); + +__u32 __skb_get_hash_flowi4(struct sk_buff *skb, struct flowi4 *fl4) +{ + struct flow_keys keys; + + memset(&keys, 0, sizeof(keys)); + + keys.addrs.v4addrs.src = fl4->saddr; + keys.addrs.v4addrs.dst = fl4->daddr; + keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; + keys.ports.src = fl4->fl4_sport; + keys.ports.dst = fl4->fl4_dport; + keys.keyid.keyid = fl4->fl4_gre_key; + keys.basic.ip_proto = fl4->flowi4_proto; + + __skb_set_sw_hash(skb, flow_hash_from_keys(&keys), &keys); + + return skb->hash; +} +EXPORT_SYMBOL(__skb_get_hash_flowi4); + u32 __skb_get_poff(const struct sk_buff *skb, void *data, const struct flow_keys *keys, int hlen) { -- 2.45.2