+ table = genl_dereference(dp->table);
+ flow = ovs_flow_tbl_lookup(table, &key, key_len);
+ if (!flow) {
+ struct sw_flow_actions *acts;
+
+ /* Bail out if we're not allowed to create a new flow. */
+ error = -ENOENT;
+ if (info->genlhdr->cmd == OVS_FLOW_CMD_SET)
+ goto error;
+
+ /* Expand table, if necessary, to make room. */
+ if (ovs_flow_tbl_need_to_expand(table)) {
+ struct flow_table *new_table;
+
+ new_table = ovs_flow_tbl_expand(table);
+ if (!IS_ERR(new_table)) {
+ rcu_assign_pointer(dp->table, new_table);
+ ovs_flow_tbl_deferred_destroy(table);
+ table = genl_dereference(dp->table);
+ }
+ }
+
+ /* Allocate flow. */
+ flow = ovs_flow_alloc();
+ if (IS_ERR(flow)) {
+ error = PTR_ERR(flow);
+ goto error;
+ }
+ flow->key = key;
+ clear_stats(flow);
+
+ /* Obtain actions. */
+ acts = ovs_flow_actions_alloc(a[OVS_FLOW_ATTR_ACTIONS]);
+ error = PTR_ERR(acts);
+ if (IS_ERR(acts))
+ goto error_free_flow;
+ rcu_assign_pointer(flow->sf_acts, acts);
+
+ /* Put flow in bucket. */
+ flow->hash = ovs_flow_hash(&key, key_len);
+ ovs_flow_tbl_insert(table, flow);
+
+ reply = ovs_flow_cmd_build_info(flow, dp, info->snd_pid,
+ info->snd_seq,
+ OVS_FLOW_CMD_NEW);
+ } else {
+ /* We found a matching flow. */
+ struct sw_flow_actions *old_acts;
+ struct nlattr *acts_attrs;
+
+ /* Bail out if we're not allowed to modify an existing flow.
+ * We accept NLM_F_CREATE in place of the intended NLM_F_EXCL
+ * because Generic Netlink treats the latter as a dump
+ * request. We also accept NLM_F_EXCL in case that bug ever
+ * gets fixed.
+ */
+ error = -EEXIST;
+ if (info->genlhdr->cmd == OVS_FLOW_CMD_NEW &&
+ info->nlhdr->nlmsg_flags & (NLM_F_CREATE | NLM_F_EXCL))
+ goto error;
+
+ /* Update actions. */
+ old_acts = rcu_dereference_protected(flow->sf_acts,
+ lockdep_genl_is_held());
+ acts_attrs = a[OVS_FLOW_ATTR_ACTIONS];
+ if (acts_attrs &&
+ (old_acts->actions_len != nla_len(acts_attrs) ||
+ memcmp(old_acts->actions, nla_data(acts_attrs),
+ old_acts->actions_len))) {
+ struct sw_flow_actions *new_acts;
+
+ new_acts = ovs_flow_actions_alloc(acts_attrs);
+ error = PTR_ERR(new_acts);
+ if (IS_ERR(new_acts))
+ goto error;
+
+ rcu_assign_pointer(flow->sf_acts, new_acts);
+ ovs_flow_deferred_free_acts(old_acts);
+ }
+
+ reply = ovs_flow_cmd_build_info(flow, dp, info->snd_pid,
+ info->snd_seq, OVS_FLOW_CMD_NEW);
+
+ /* Clear stats. */
+ if (a[OVS_FLOW_ATTR_CLEAR]) {
+ spin_lock_bh(&flow->lock);
+ clear_stats(flow);
+ spin_unlock_bh(&flow->lock);