+static void dccp_v4_reqsk_destructor(struct request_sock *req)
+{
+ kfree(inet_rsk(req)->opt);
+}
+
+static struct request_sock_ops dccp_request_sock_ops __read_mostly = {
+ .family = PF_INET,
+ .obj_size = sizeof(struct dccp_request_sock),
+ .rtx_syn_ack = dccp_v4_send_response,
+ .send_ack = dccp_reqsk_send_ack,
+ .destructor = dccp_v4_reqsk_destructor,
+ .send_reset = dccp_v4_ctl_send_reset,
+};
+
+int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
+{
+ struct inet_request_sock *ireq;
+ struct request_sock *req;
+ struct dccp_request_sock *dreq;
+ const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
+ struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
+ __u8 reset_code = DCCP_RESET_CODE_TOO_BUSY;
+
+ /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
+ if (((struct rtable *)skb->dst)->rt_flags &
+ (RTCF_BROADCAST | RTCF_MULTICAST)) {
+ reset_code = DCCP_RESET_CODE_NO_CONNECTION;
+ goto drop;
+ }
+
+ if (dccp_bad_service_code(sk, service)) {
+ reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
+ goto drop;
+ }
+ /*
+ * TW buckets are converted to open requests without
+ * limitations, they conserve resources and peer is
+ * evidently real one.
+ */
+ if (inet_csk_reqsk_queue_is_full(sk))
+ goto drop;
+
+ /*
+ * Accept backlog is full. If we have already queued enough
+ * of warm entries in syn queue, drop request. It is better than
+ * clogging syn queue with openreqs with exponentially increasing
+ * timeout.
+ */
+ if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
+ goto drop;
+
+ req = reqsk_alloc(&dccp_request_sock_ops);
+ if (req == NULL)
+ goto drop;
+
+ if (dccp_parse_options(sk, skb))
+ goto drop_and_free;
+
+ dccp_reqsk_init(req, skb);
+
+ if (security_inet_conn_request(sk, skb, req))
+ goto drop_and_free;
+
+ ireq = inet_rsk(req);
+ ireq->loc_addr = skb->nh.iph->daddr;
+ ireq->rmt_addr = skb->nh.iph->saddr;
+ ireq->opt = NULL;
+
+ /*
+ * Step 3: Process LISTEN state
+ *
+ * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
+ *
+ * In fact we defer setting S.GSR, S.SWL, S.SWH to
+ * dccp_create_openreq_child.
+ */
+ dreq = dccp_rsk(req);
+ dreq->dreq_isr = dcb->dccpd_seq;
+ dreq->dreq_iss = dccp_v4_init_sequence(skb);
+ dreq->dreq_service = service;
+
+ if (dccp_v4_send_response(sk, req, NULL))
+ goto drop_and_free;
+
+ inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
+ return 0;
+
+drop_and_free:
+ reqsk_free(req);
+drop:
+ DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
+ dcb->dccpd_reset_code = reset_code;
+ return -1;
+}
+
+EXPORT_SYMBOL_GPL(dccp_v4_conn_request);
+