[PATCHv5 net-next 01/10] openvswitch: Serialize acts with original netlink len

From: Joe Stringer
Date: Mon Aug 24 2015 - 20:36:50 EST


Previously, we used the kernel-internal netlink actions length to
calculate the size of messages to serialize back to userspace.
However,the sw_flow_actions may not be formatted exactly the same as the
actions on the wire, so store the original actions length when
de-serializing and re-use the original length when serializing.

Signed-off-by: Joe Stringer <joestringer@xxxxxxxxxx>
Acked-by: Pravin B Shelar <pshelar@xxxxxxxxxx>
---
v2: No change.
v3: Preserve original length across buffer resize.
v4: Add ack.
v5: No change.
---
net/openvswitch/datapath.c | 2 +-
net/openvswitch/flow.h | 1 +
net/openvswitch/flow_netlink.c | 2 ++
3 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index ffe984f..d5b5473 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -713,7 +713,7 @@ static size_t ovs_flow_cmd_msg_size(const struct sw_flow_actions *acts,

/* OVS_FLOW_ATTR_ACTIONS */
if (should_fill_actions(ufid_flags))
- len += nla_total_size(acts->actions_len);
+ len += nla_total_size(acts->orig_len);

return len
+ nla_total_size(sizeof(struct ovs_flow_stats)) /* OVS_FLOW_ATTR_STATS */
diff --git a/net/openvswitch/flow.h b/net/openvswitch/flow.h
index b62cdb3..082a87b 100644
--- a/net/openvswitch/flow.h
+++ b/net/openvswitch/flow.h
@@ -144,6 +144,7 @@ struct sw_flow_id {

struct sw_flow_actions {
struct rcu_head rcu;
+ size_t orig_len; /* From flow_cmd_new netlink actions size */
u32 actions_len;
struct nlattr actions[];
};
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index 4e7a3f7..c182b28 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -1619,6 +1619,7 @@ static struct nlattr *reserve_sfa_size(struct sw_flow_actions **sfa,

memcpy(acts->actions, (*sfa)->actions, (*sfa)->actions_len);
acts->actions_len = (*sfa)->actions_len;
+ acts->orig_len = (*sfa)->orig_len;
kfree(*sfa);
*sfa = acts;

@@ -2223,6 +2224,7 @@ int ovs_nla_copy_actions(const struct nlattr *attr,
if (IS_ERR(*sfa))
return PTR_ERR(*sfa);

+ (*sfa)->orig_len = nla_len(attr);
err = __ovs_nla_copy_actions(attr, key, 0, sfa, key->eth.type,
key->eth.tci, log);
if (err)
--
2.1.4

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