openvswitch: Refine Netlink message size calculation and kill FLOW_BUFSIZE
Kills the FLOW_BUFSIZE constant which needs to be calculated manually
and replaces it with key_attr_size() based on nla_total_size().
Calculates the size of datapath messages instead of relying on
NLMSG_DEFAULT_SIZE and moves the existing message size calculations
into own functions for clarity.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Jesse Gross <jesse@nicira.com>
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index bca63c8..49ee37b 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -337,6 +337,35 @@
return err;
}
+static size_t key_attr_size(void)
+{
+ return nla_total_size(4) /* OVS_KEY_ATTR_PRIORITY */
+ + nla_total_size(4) /* OVS_KEY_ATTR_IN_PORT */
+ + nla_total_size(4) /* OVS_KEY_ATTR_SKB_MARK */
+ + nla_total_size(12) /* OVS_KEY_ATTR_ETHERNET */
+ + nla_total_size(2) /* OVS_KEY_ATTR_ETHERTYPE */
+ + nla_total_size(4) /* OVS_KEY_ATTR_8021Q */
+ + nla_total_size(0) /* OVS_KEY_ATTR_ENCAP */
+ + nla_total_size(2) /* OVS_KEY_ATTR_ETHERTYPE */
+ + nla_total_size(40) /* OVS_KEY_ATTR_IPV6 */
+ + nla_total_size(2) /* OVS_KEY_ATTR_ICMPV6 */
+ + nla_total_size(28); /* OVS_KEY_ATTR_ND */
+}
+
+static size_t upcall_msg_size(const struct sk_buff *skb,
+ const struct nlattr *userdata)
+{
+ size_t size = NLMSG_ALIGN(sizeof(struct ovs_header))
+ + nla_total_size(skb->len) /* OVS_PACKET_ATTR_PACKET */
+ + nla_total_size(key_attr_size()); /* OVS_PACKET_ATTR_KEY */
+
+ /* OVS_PACKET_ATTR_USERDATA */
+ if (userdata)
+ size += NLA_ALIGN(userdata->nla_len);
+
+ return size;
+}
+
static int queue_userspace_packet(struct net *net, int dp_ifindex,
struct sk_buff *skb,
const struct dp_upcall_info *upcall_info)
@@ -345,7 +374,6 @@
struct sk_buff *nskb = NULL;
struct sk_buff *user_skb; /* to be queued to userspace */
struct nlattr *nla;
- unsigned int len;
int err;
if (vlan_tx_tag_present(skb)) {
@@ -366,13 +394,7 @@
goto out;
}
- len = sizeof(struct ovs_header);
- len += nla_total_size(skb->len);
- len += nla_total_size(FLOW_BUFSIZE);
- if (upcall_info->userdata)
- len += NLA_ALIGN(upcall_info->userdata->nla_len);
-
- user_skb = genlmsg_new(len, GFP_ATOMIC);
+ user_skb = genlmsg_new(upcall_msg_size(skb, upcall_info->userdata), GFP_ATOMIC);
if (!user_skb) {
err = -ENOMEM;
goto out;
@@ -801,6 +823,16 @@
.name = OVS_FLOW_MCGROUP
};
+static size_t ovs_flow_cmd_msg_size(const struct sw_flow_actions *acts)
+{
+ return NLMSG_ALIGN(sizeof(struct ovs_header))
+ + nla_total_size(key_attr_size()) /* OVS_FLOW_ATTR_KEY */
+ + nla_total_size(sizeof(struct ovs_flow_stats)) /* OVS_FLOW_ATTR_STATS */
+ + nla_total_size(1) /* OVS_FLOW_ATTR_TCP_FLAGS */
+ + nla_total_size(8) /* OVS_FLOW_ATTR_USED */
+ + nla_total_size(acts->actions_len); /* OVS_FLOW_ATTR_ACTIONS */
+}
+
/* Called with genl_lock. */
static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
struct sk_buff *skb, u32 portid,
@@ -879,25 +911,11 @@
static struct sk_buff *ovs_flow_cmd_alloc_info(struct sw_flow *flow)
{
const struct sw_flow_actions *sf_acts;
- int len;
sf_acts = rcu_dereference_protected(flow->sf_acts,
lockdep_genl_is_held());
- /* OVS_FLOW_ATTR_KEY */
- len = nla_total_size(FLOW_BUFSIZE);
- /* OVS_FLOW_ATTR_ACTIONS */
- len += nla_total_size(sf_acts->actions_len);
- /* OVS_FLOW_ATTR_STATS */
- len += nla_total_size(sizeof(struct ovs_flow_stats));
- /* OVS_FLOW_ATTR_TCP_FLAGS */
- len += nla_total_size(1);
- /* OVS_FLOW_ATTR_USED */
- len += nla_total_size(8);
-
- len += NLMSG_ALIGN(sizeof(struct ovs_header));
-
- return genlmsg_new(len, GFP_KERNEL);
+ return genlmsg_new(ovs_flow_cmd_msg_size(sf_acts), GFP_KERNEL);
}
static struct sk_buff *ovs_flow_cmd_build_info(struct sw_flow *flow,
@@ -1213,6 +1231,16 @@
.name = OVS_DATAPATH_MCGROUP
};
+static size_t ovs_dp_cmd_msg_size(void)
+{
+ size_t msgsize = NLMSG_ALIGN(sizeof(struct ovs_header));
+
+ msgsize += nla_total_size(IFNAMSIZ);
+ msgsize += nla_total_size(sizeof(struct ovs_dp_stats));
+
+ return msgsize;
+}
+
static int ovs_dp_cmd_fill_info(struct datapath *dp, struct sk_buff *skb,
u32 portid, u32 seq, u32 flags, u8 cmd)
{
@@ -1251,7 +1279,7 @@
struct sk_buff *skb;
int retval;
- skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ skb = genlmsg_new(ovs_dp_cmd_msg_size(), GFP_KERNEL);
if (!skb)
return ERR_PTR(-ENOMEM);