+/* Called with genl_lock. */
+static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
+ struct sk_buff *skb, u32 pid,
+ u32 seq, u32 flags, u8 cmd)
+{
+ const int skb_orig_len = skb->len;
+ const struct sw_flow_actions *sf_acts;
+ struct ovs_flow_stats stats;
+ struct ovs_header *ovs_header;
+ struct nlattr *nla;
+ unsigned long used;
+ u8 tcp_flags;
+ int err;
+
+ sf_acts = rcu_dereference_protected(flow->sf_acts,
+ lockdep_genl_is_held());
+
+ ovs_header = genlmsg_put(skb, pid, seq, &dp_flow_genl_family, flags, cmd);
+ if (!ovs_header)
+ return -EMSGSIZE;
+
+ ovs_header->dp_ifindex = get_dpifindex(dp);
+
+ nla = nla_nest_start(skb, OVS_FLOW_ATTR_KEY);
+ if (!nla)
+ goto nla_put_failure;
+ err = ovs_flow_to_nlattrs(&flow->key, skb);
+ if (err)
+ goto error;
+ nla_nest_end(skb, nla);
+
+ spin_lock_bh(&flow->lock);
+ used = flow->used;
+ stats.n_packets = flow->packet_count;
+ stats.n_bytes = flow->byte_count;
+ tcp_flags = flow->tcp_flags;
+ spin_unlock_bh(&flow->lock);
+
+ if (used &&
+ nla_put_u64(skb, OVS_FLOW_ATTR_USED, ovs_flow_used_time(used)))
+ goto nla_put_failure;
+
+ if (stats.n_packets &&
+ nla_put(skb, OVS_FLOW_ATTR_STATS,
+ sizeof(struct ovs_flow_stats), &stats))
+ goto nla_put_failure;
+
+ if (tcp_flags &&
+ nla_put_u8(skb, OVS_FLOW_ATTR_TCP_FLAGS, tcp_flags))
+ goto nla_put_failure;
+
+ /* If OVS_FLOW_ATTR_ACTIONS doesn't fit, skip dumping the actions if
+ * this is the first flow to be dumped into 'skb'. This is unusual for
+ * Netlink but individual action lists can be longer than
+ * NLMSG_GOODSIZE and thus entirely undumpable if we didn't do this.
+ * The userspace caller can always fetch the actions separately if it
+ * really wants them. (Most userspace callers in fact don't care.)
+ *
+ * This can only fail for dump operations because the skb is always
+ * properly sized for single flows.
+ */
+ err = nla_put(skb, OVS_FLOW_ATTR_ACTIONS, sf_acts->actions_len,
+ sf_acts->actions);
+ if (err < 0 && skb_orig_len)
+ goto error;
+
+ return genlmsg_end(skb, ovs_header);
+
+nla_put_failure:
+ err = -EMSGSIZE;
+error:
+ genlmsg_cancel(skb, ovs_header);
+ return err;