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Message-ID: <1445423785-4654-6-git-send-email-paul.durrant@citrix.com>
Date: Wed, 21 Oct 2015 11:36:22 +0100
From: Paul Durrant <paul.durrant@...rix.com>
To: <netdev@...r.kernel.org>, <xen-devel@...ts.xenproject.org>
CC: Paul Durrant <paul.durrant@...rix.com>,
"David S. Miller" <davem@...emloft.net>,
Jay Vosburgh <j.vosburgh@...il.com>,
Veaceslav Falico <vfalico@...il.com>,
Andy Gospodarek <gospo@...ulusnetworks.com>
Subject: [PATCH net-next 5/8] skbuff: store hash type in socket buffer...
...rather than a boolean merely indicating a canonical L4 hash.
skb_set_hash() takes a hash type (from enum pkt_hash_types) as an
argument but information is lost since only a single bit in the skb
stores whether that hash type is PKT_HASH_TYPE_L4 or not.
By using two bits it's possible to store the complete hash type
information for use by drivers, such as xen-netback when forwarding
network packets to VM frontend drivers.
Signed-off-by: Paul Durrant <paul.durrant@...rix.com>
Cc: "David S. Miller" <davem@...emloft.net>
Cc: Jay Vosburgh <j.vosburgh@...il.com>
Cc: Veaceslav Falico <vfalico@...il.com>
Cc: Andy Gospodarek <gospo@...ulusnetworks.com>
---
drivers/net/bonding/bond_main.c | 2 +-
include/linux/skbuff.h | 53 ++++++++++++++++++++++++++++-------------
include/net/flow_dissector.h | 5 ++++
include/net/sock.h | 2 +-
include/trace/events/net.h | 2 +-
net/core/flow_dissector.c | 27 ++++++++++++++++-----
6 files changed, 65 insertions(+), 26 deletions(-)
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index d0f23cd..abf9c3f 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -3137,7 +3137,7 @@ u32 bond_xmit_hash(struct bonding *bond, struct sk_buff *skb)
u32 hash;
if (bond->params.xmit_policy == BOND_XMIT_POLICY_ENCAP34 &&
- skb->l4_hash)
+ skb_has_l4_hash(skb))
return skb->hash;
if (bond->params.xmit_policy == BOND_XMIT_POLICY_LAYER2 ||
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 4398411..30e1e60 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -506,8 +506,7 @@ static inline u32 skb_mstamp_us_delta(const struct skb_mstamp *t1,
* @xmit_more: More SKBs are pending for this queue
* @ndisc_nodetype: router type (from link layer)
* @ooo_okay: allow the mapping of a socket to a queue to be changed
- * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
- * ports.
+ * @hash_type: indicates type of hash (see enum pkt_hash_types below)
* @sw_hash: indicates hash was computed in software stack
* @wifi_acked_valid: wifi_acked was set
* @wifi_acked: whether frame was acked on wifi or not
@@ -612,10 +611,10 @@ struct sk_buff {
__u8 nf_trace:1;
__u8 ip_summed:2;
__u8 ooo_okay:1;
- __u8 l4_hash:1;
__u8 sw_hash:1;
__u8 wifi_acked_valid:1;
__u8 wifi_acked:1;
+ /* 1 bit hole */
__u8 no_fcs:1;
/* Indicates the inner headers are valid in the skbuff. */
@@ -632,7 +631,8 @@ struct sk_buff {
__u8 ipvs_property:1;
__u8 inner_protocol_type:1;
__u8 remcsum_offload:1;
- /* 3 or 5 bit hole */
+ __u8 hash_type:2;
+ /* 1 or 3 bit hole */
#ifdef CONFIG_NET_SCHED
__u16 tc_index; /* traffic control index */
@@ -941,19 +941,35 @@ static inline void skb_clear_hash(struct sk_buff *skb)
{
skb->hash = 0;
skb->sw_hash = 0;
- skb->l4_hash = 0;
+ skb->hash_type = 0;
+}
+
+static inline enum pkt_hash_types skb_hash_type(struct sk_buff *skb)
+{
+ return skb->hash_type;
+}
+
+static inline bool skb_has_l4_hash(struct sk_buff *skb)
+{
+ return skb_hash_type(skb) == PKT_HASH_TYPE_L4;
+}
+
+static inline bool skb_has_sw_hash(struct sk_buff *skb)
+{
+ return !!skb->sw_hash;
}
static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb)
{
- if (!skb->l4_hash)
+ if (!skb_has_l4_hash(skb))
skb_clear_hash(skb);
}
static inline void
-__skb_set_hash(struct sk_buff *skb, __u32 hash, bool is_sw, bool is_l4)
+__skb_set_hash(struct sk_buff *skb, __u32 hash, bool is_sw,
+ enum pkt_hash_types type)
{
- skb->l4_hash = is_l4;
+ skb->hash_type = type;
skb->sw_hash = is_sw;
skb->hash = hash;
}
@@ -962,13 +978,13 @@ static inline void
skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type)
{
/* Used by drivers to set hash from HW */
- __skb_set_hash(skb, hash, false, type == PKT_HASH_TYPE_L4);
+ __skb_set_hash(skb, hash, false, type);
}
static inline void
-__skb_set_sw_hash(struct sk_buff *skb, __u32 hash, bool is_l4)
+__skb_set_sw_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type)
{
- __skb_set_hash(skb, hash, true, is_l4);
+ __skb_set_hash(skb, hash, true, type);
}
void __skb_get_hash(struct sk_buff *skb);
@@ -1021,9 +1037,10 @@ static inline bool skb_flow_dissect_flow_keys_buf(struct flow_keys *flow,
data, proto, nhoff, hlen, flags);
}
+
static inline __u32 skb_get_hash(struct sk_buff *skb)
{
- if (!skb->l4_hash && !skb->sw_hash)
+ if (!skb_has_l4_hash(skb) && !skb_has_sw_hash(skb))
__skb_get_hash(skb);
return skb->hash;
@@ -1033,11 +1050,12 @@ __u32 __skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6);
static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
{
- if (!skb->l4_hash && !skb->sw_hash) {
+ if (!skb_has_l4_hash(skb) && !skb_has_sw_hash(skb)) {
struct flow_keys keys;
__u32 hash = __get_hash_from_flowi6(fl6, &keys);
- __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
+ __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys) ?
+ PKT_HASH_TYPE_L4 : PKT_HASH_TYPE_L3);
}
return skb->hash;
@@ -1047,11 +1065,12 @@ __u32 __skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl);
static inline __u32 skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl4)
{
- if (!skb->l4_hash && !skb->sw_hash) {
+ if (!skb_has_l4_hash(skb) && !skb_has_sw_hash(skb)) {
struct flow_keys keys;
__u32 hash = __get_hash_from_flowi4(fl4, &keys);
- __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
+ __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys) ?
+ PKT_HASH_TYPE_L4 : PKT_HASH_TYPE_L3);
}
return skb->hash;
@@ -1068,7 +1087,7 @@ static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from)
{
to->hash = from->hash;
to->sw_hash = from->sw_hash;
- to->l4_hash = from->l4_hash;
+ to->hash_type = from->hash_type;
};
static inline void skb_sender_cpu_clear(struct sk_buff *skb)
diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
index 8c8548c..418b8c5 100644
--- a/include/net/flow_dissector.h
+++ b/include/net/flow_dissector.h
@@ -182,6 +182,11 @@ static inline bool flow_keys_have_l4(struct flow_keys *keys)
return (keys->ports.ports || keys->tags.flow_label);
}
+static inline bool flow_keys_have_l3(struct flow_keys *keys)
+{
+ return !!keys->control.addr_type;
+}
+
u32 flow_hash_from_keys(struct flow_keys *keys);
#endif
diff --git a/include/net/sock.h b/include/net/sock.h
index 64a7545..b9f68db 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1938,7 +1938,7 @@ static inline void sock_poll_wait(struct file *filp,
static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
{
if (sk->sk_txhash) {
- skb->l4_hash = 1;
+ skb->hash_type = PKT_HASH_TYPE_L4;
skb->hash = sk->sk_txhash;
}
}
diff --git a/include/trace/events/net.h b/include/trace/events/net.h
index 49cc7c3..25e7979 100644
--- a/include/trace/events/net.h
+++ b/include/trace/events/net.h
@@ -180,7 +180,7 @@ DECLARE_EVENT_CLASS(net_dev_rx_verbose_template,
__entry->protocol = ntohs(skb->protocol);
__entry->ip_summed = skb->ip_summed;
__entry->hash = skb->hash;
- __entry->l4_hash = skb->l4_hash;
+ __entry->l4_hash = skb->hash_type == PKT_HASH_TYPE_L4;
__entry->len = skb->len;
__entry->data_len = skb->data_len;
__entry->truesize = skb->truesize;
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index d79699c..956208b 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -658,17 +658,30 @@ EXPORT_SYMBOL(make_flow_keys_digest);
*
* This function calculates a flow hash based on src/dst addresses
* and src/dst port numbers. Sets hash in skb to non-zero hash value
- * on success, zero indicates no valid hash. Also, sets l4_hash in skb
- * if hash is a canonical 4-tuple hash over transport ports.
+ * on success, zero indicates no valid hash in which case the hash type
+ * is set to NONE. If the hash is a canonical 4-tuple hash over transport
+ * ports then type is set to L4. If the hash did not include transport
+ * then type is set to L3, otherwise it is assumed to be L2 only.
*/
void __skb_get_hash(struct sk_buff *skb)
{
struct flow_keys keys;
+ u32 hash;
+ enum pkt_hash_types type;
__flow_hash_secret_init();
- __skb_set_sw_hash(skb, ___skb_get_hash(skb, &keys, hashrnd),
- flow_keys_have_l4(&keys));
+ hash = ___skb_get_hash(skb, &keys, hashrnd);
+ if (hash == 0)
+ type = PKT_HASH_TYPE_NONE;
+ else if (flow_keys_have_l4(&keys))
+ type = PKT_HASH_TYPE_L4;
+ else if (flow_keys_have_l3(&keys))
+ type = PKT_HASH_TYPE_L3;
+ else
+ type = PKT_HASH_TYPE_L2;
+
+ __skb_set_sw_hash(skb, hash, type);
}
EXPORT_SYMBOL(__skb_get_hash);
@@ -698,7 +711,8 @@ __u32 __skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
keys.basic.ip_proto = fl6->flowi6_proto;
__skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
- flow_keys_have_l4(&keys));
+ flow_keys_have_l4(&keys) ?
+ PKT_HASH_TYPE_L4 : PKT_HASH_TYPE_L3);
return skb->hash;
}
@@ -719,7 +733,8 @@ __u32 __skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl4)
keys.basic.ip_proto = fl4->flowi4_proto;
__skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
- flow_keys_have_l4(&keys));
+ flow_keys_have_l4(&keys) ?
+ PKT_HASH_TYPE_L4 : PKT_HASH_TYPE_L3);
return skb->hash;
}
--
2.1.4
--
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