1 files changed, 600 insertions, 0 deletions

diff --git a/net/dccp/input.c b/net/dccp/input.c
new file mode 100644
index 000000000000..ef29cef1dafe
--- /dev/null
+++ b/net/dccp/input.c
@@ -0,0 +1,600 @@
+/*
+ *  net/dccp/input.c
+ * 
+ *  An implementation of the DCCP protocol
+ *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/dccp.h>
+#include <linux/skbuff.h>
+
+#include <net/sock.h>
+
+#include "ccid.h"
+#include "dccp.h"
+
+static void dccp_fin(struct sock *sk, struct sk_buff *skb)
+{
+        sk->sk_shutdown |= RCV_SHUTDOWN;
+        sock_set_flag(sk, SOCK_DONE);
+        __skb_pull(skb, dccp_hdr(skb)->dccph_doff * 4);
+        __skb_queue_tail(&sk->sk_receive_queue, skb);
+        skb_set_owner_r(skb, sk);
+        sk->sk_data_ready(sk, 0);
+}
+
+static void dccp_rcv_close(struct sock *sk, struct sk_buff *skb)
+{
+        dccp_v4_send_reset(sk, DCCP_RESET_CODE_CLOSED);
+        dccp_fin(sk, skb);
+        dccp_set_state(sk, DCCP_CLOSED);
+        sk_wake_async(sk, 1, POLL_HUP);
+}
+
+static void dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb)
+{
+        /*
+         *   Step 7: Check for unexpected packet types
+         *      If (S.is_server and P.type == CloseReq)
+         *        Send Sync packet acknowledging P.seqno
+         *        Drop packet and return
+         */
+        if (dccp_sk(sk)->dccps_role != DCCP_ROLE_CLIENT) {
+                dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC);
+                return;
+        }
+
+        dccp_set_state(sk, DCCP_CLOSING);
+        dccp_send_close(sk, 0);
+}
+
+static inline void dccp_event_ack_recv(struct sock *sk, struct sk_buff *skb)
+{
+        struct dccp_sock *dp = dccp_sk(sk);
+
+        if (dp->dccps_options.dccpo_send_ack_vector)
+                dccp_ackpkts_check_rcv_ackno(dp->dccps_hc_rx_ackpkts, sk,
+                                             DCCP_SKB_CB(skb)->dccpd_ack_seq);
+}
+
+static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb)
+{
+        const struct dccp_hdr *dh = dccp_hdr(skb);
+        struct dccp_sock *dp = dccp_sk(sk);
+        u64 lswl, lawl;
+
+        /*
+         *   Step 5: Prepare sequence numbers for Sync
+         *     If P.type == Sync or P.type == SyncAck,
+         *        If S.AWL <= P.ackno <= S.AWH and P.seqno >= S.SWL,
+         *           / * P is valid, so update sequence number variables
+         *               accordingly.  After this update, P will pass the tests
+         *               in Step 6.  A SyncAck is generated if necessary in
+         *               Step 15 * /
+         *           Update S.GSR, S.SWL, S.SWH
+         *        Otherwise,
+         *           Drop packet and return
+         */
+        if (dh->dccph_type == DCCP_PKT_SYNC || 
+            dh->dccph_type == DCCP_PKT_SYNCACK) {
+                if (between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
+                              dp->dccps_awl, dp->dccps_awh) &&
+                    !before48(DCCP_SKB_CB(skb)->dccpd_seq, dp->dccps_swl))
+                        dccp_update_gsr(sk, DCCP_SKB_CB(skb)->dccpd_seq);
+                else
+                        return -1;
+        }
+        
+        /*
+         *   Step 6: Check sequence numbers
+         *      Let LSWL = S.SWL and LAWL = S.AWL
+         *      If P.type == CloseReq or P.type == Close or P.type == Reset,
+         *        LSWL := S.GSR + 1, LAWL := S.GAR
+         *      If LSWL <= P.seqno <= S.SWH
+         *           and (P.ackno does not exist or LAWL <= P.ackno <= S.AWH),
+         *        Update S.GSR, S.SWL, S.SWH
+         *        If P.type != Sync,
+         *           Update S.GAR
+         *      Otherwise,
+         *        Send Sync packet acknowledging P.seqno
+         *        Drop packet and return
+         */
+        lswl = dp->dccps_swl;
+        lawl = dp->dccps_awl;
+
+        if (dh->dccph_type == DCCP_PKT_CLOSEREQ ||
+            dh->dccph_type == DCCP_PKT_CLOSE ||
+            dh->dccph_type == DCCP_PKT_RESET) {
+                lswl = dp->dccps_gsr;
+                dccp_inc_seqno(&lswl);
+                lawl = dp->dccps_gar;
+        }
+
+        if (between48(DCCP_SKB_CB(skb)->dccpd_seq, lswl, dp->dccps_swh) &&
+            (DCCP_SKB_CB(skb)->dccpd_ack_seq == DCCP_PKT_WITHOUT_ACK_SEQ ||
+             between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
+                       lawl, dp->dccps_awh))) {
+                dccp_update_gsr(sk, DCCP_SKB_CB(skb)->dccpd_seq);
+
+                if (dh->dccph_type != DCCP_PKT_SYNC &&
+                    (DCCP_SKB_CB(skb)->dccpd_ack_seq !=
+                     DCCP_PKT_WITHOUT_ACK_SEQ))
+                        dp->dccps_gar = DCCP_SKB_CB(skb)->dccpd_ack_seq;
+        } else {
+                LIMIT_NETDEBUG(KERN_WARNING "DCCP: Step 6 failed for %s packet, "
+                                            "(LSWL(%llu) <= P.seqno(%llu) <= S.SWH(%llu)) and "
+                                            "(P.ackno %s or LAWL(%llu) <= P.ackno(%llu) <= S.AWH(%llu), "
+                                            "sending SYNC...\n",
+                               dccp_packet_name(dh->dccph_type),
+                               (unsigned long long) lswl,
+                               (unsigned long long)
+                               DCCP_SKB_CB(skb)->dccpd_seq,
+                               (unsigned long long) dp->dccps_swh,
+                               (DCCP_SKB_CB(skb)->dccpd_ack_seq ==
+                                DCCP_PKT_WITHOUT_ACK_SEQ) ? "doesn't exist" : "exists",
+                               (unsigned long long) lawl,
+                               (unsigned long long)
+                               DCCP_SKB_CB(skb)->dccpd_ack_seq,
+                               (unsigned long long) dp->dccps_awh);
+                dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC);
+                return -1;
+        }
+
+        return 0;
+}
+
+int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
+                         const struct dccp_hdr *dh, const unsigned len)
+{
+        struct dccp_sock *dp = dccp_sk(sk);
+
+        if (dccp_check_seqno(sk, skb))
+                goto discard;
+
+        if (dccp_parse_options(sk, skb))
+                goto discard;
+
+        if (DCCP_SKB_CB(skb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
+                dccp_event_ack_recv(sk, skb);
+
+        /*
+         * FIXME: check ECN to see if we should use
+         * DCCP_ACKPKTS_STATE_ECN_MARKED
+         */
+        if (dp->dccps_options.dccpo_send_ack_vector) {
+                struct dccp_ackpkts *ap = dp->dccps_hc_rx_ackpkts;
+
+                if (dccp_ackpkts_add(dp->dccps_hc_rx_ackpkts,
+                                     DCCP_SKB_CB(skb)->dccpd_seq,
+                                     DCCP_ACKPKTS_STATE_RECEIVED)) {
+                        LIMIT_NETDEBUG(KERN_WARNING "DCCP: acknowledgeable "
+                                                    "packets buffer full!\n");
+                        ap->dccpap_ack_seqno = DCCP_MAX_SEQNO + 1;
+                        inet_csk_schedule_ack(sk);
+                        inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
+                                                  TCP_DELACK_MIN,
+                                                  DCCP_RTO_MAX);
+                        goto discard;
+                }
+
+                /*
+                 * FIXME: this activation is probably wrong, have to study more
+                 * TCP delack machinery and how it fits into DCCP draft, but
+                 * for now it kinda "works" 8)
+                 */
+                if (!inet_csk_ack_scheduled(sk)) {
+                        inet_csk_schedule_ack(sk);
+                        inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, 5 * HZ,
+                                                  DCCP_RTO_MAX);
+                }
+        }
+
+        ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
+        ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb);
+
+        switch (dccp_hdr(skb)->dccph_type) {
+        case DCCP_PKT_DATAACK:
+        case DCCP_PKT_DATA:
+                /*
+                 * FIXME: check if sk_receive_queue is full, schedule DATA_DROPPED
+                 * option if it is.
+                 */
+                __skb_pull(skb, dh->dccph_doff * 4);
+                __skb_queue_tail(&sk->sk_receive_queue, skb);
+                skb_set_owner_r(skb, sk);
+                sk->sk_data_ready(sk, 0);
+                return 0;
+        case DCCP_PKT_ACK:
+                goto discard;
+        case DCCP_PKT_RESET:
+                /*
+                 *  Step 9: Process Reset
+                 *      If P.type == Reset,
+                 *              Tear down connection
+                 *              S.state := TIMEWAIT
+                 *              Set TIMEWAIT timer
+                 *              Drop packet and return
+                */
+                dccp_fin(sk, skb);
+                dccp_time_wait(sk, DCCP_TIME_WAIT, 0);
+                return 0;
+        case DCCP_PKT_CLOSEREQ:
+                dccp_rcv_closereq(sk, skb);
+                goto discard;
+        case DCCP_PKT_CLOSE:
+                dccp_rcv_close(sk, skb);
+                return 0;
+        case DCCP_PKT_REQUEST:
+                /* Step 7 
+                 *   or (S.is_server and P.type == Response)
+                 *   or (S.is_client and P.type == Request)
+                 *   or (S.state >= OPEN and P.type == Request
+                 *      and P.seqno >= S.OSR)
+                 *    or (S.state >= OPEN and P.type == Response
+                 *      and P.seqno >= S.OSR)
+                 *    or (S.state == RESPOND and P.type == Data),
+                 *  Send Sync packet acknowledging P.seqno
+                 *  Drop packet and return
+                 */
+                if (dp->dccps_role != DCCP_ROLE_LISTEN)
+                        goto send_sync;
+                goto check_seq;
+        case DCCP_PKT_RESPONSE:
+                if (dp->dccps_role != DCCP_ROLE_CLIENT)
+                        goto send_sync;
+check_seq:
+                if (!before48(DCCP_SKB_CB(skb)->dccpd_seq, dp->dccps_osr)) {
+send_sync:
+                        dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq,
+                                       DCCP_PKT_SYNC);
+                }
+                break;
+        case DCCP_PKT_SYNC:
+                dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq,
+                               DCCP_PKT_SYNCACK);
+                /*
+                 * From the draft:
+                 *
+                 * As with DCCP-Ack packets, DCCP-Sync and DCCP-SyncAck packets
+                 * MAY have non-zero-length application data areas, whose
+                 * contents * receivers MUST ignore.
+                 */
+                goto discard;
+        }
+
+        DCCP_INC_STATS_BH(DCCP_MIB_INERRS);
+discard:
+        __kfree_skb(skb);
+        return 0;
+}
+
+static int dccp_rcv_request_sent_state_process(struct sock *sk,
+                                               struct sk_buff *skb,
+                                               const struct dccp_hdr *dh,
+                                               const unsigned len)
+{
+        /* 
+         *  Step 4: Prepare sequence numbers in REQUEST
+         *     If S.state == REQUEST,
+         *        If (P.type == Response or P.type == Reset)
+         *              and S.AWL <= P.ackno <= S.AWH,
+         *           / * Set sequence number variables corresponding to the
+         *              other endpoint, so P will pass the tests in Step 6 * /
+         *           Set S.GSR, S.ISR, S.SWL, S.SWH
+         *           / * Response processing continues in Step 10; Reset
+         *              processing continues in Step 9 * /
+        */
+        if (dh->dccph_type == DCCP_PKT_RESPONSE) {
+                const struct inet_connection_sock *icsk = inet_csk(sk);
+                struct dccp_sock *dp = dccp_sk(sk);
+
+                /* Stop the REQUEST timer */
+                inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS);
+                BUG_TRAP(sk->sk_send_head != NULL);
+                __kfree_skb(sk->sk_send_head);
+                sk->sk_send_head = NULL;
+
+                if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
+                               dp->dccps_awl, dp->dccps_awh)) {
+                        dccp_pr_debug("invalid ackno: S.AWL=%llu, "
+                                      "P.ackno=%llu, S.AWH=%llu \n",
+                                      (unsigned long long)dp->dccps_awl,
+                           (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq,
+                                      (unsigned long long)dp->dccps_awh);
+                        goto out_invalid_packet;
+                }
+
+                dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq;
+                dccp_update_gsr(sk, dp->dccps_isr);
+                /*
+                 * SWL and AWL are initially adjusted so that they are not less than
+                 * the initial Sequence Numbers received and sent, respectively:
+                 *      SWL := max(GSR + 1 - floor(W/4), ISR),
+                 *      AWL := max(GSS - W' + 1, ISS).
+                 * These adjustments MUST be applied only at the beginning of the
+                 * connection.
+                 *
+                 * AWL was adjusted in dccp_v4_connect -acme
+                 */
+                dccp_set_seqno(&dp->dccps_swl,
+                               max48(dp->dccps_swl, dp->dccps_isr));
+
+                if (ccid_hc_rx_init(dp->dccps_hc_rx_ccid, sk) != 0 ||
+                    ccid_hc_tx_init(dp->dccps_hc_tx_ccid, sk) != 0) {
+                        ccid_hc_rx_exit(dp->dccps_hc_rx_ccid, sk);
+                        ccid_hc_tx_exit(dp->dccps_hc_tx_ccid, sk);
+                        /* FIXME: send appropriate RESET code */
+                        goto out_invalid_packet;
+                }
+
+                dccp_sync_mss(sk, dp->dccps_pmtu_cookie);
+
+                /*
+                 *    Step 10: Process REQUEST state (second part)
+                 *       If S.state == REQUEST,
+                 *        / * If we get here, P is a valid Response from the
+                 *            server (see Step 4), and we should move to
+                 *            PARTOPEN state. PARTOPEN means send an Ack,
+                 *            don't send Data packets, retransmit Acks
+                 *            periodically, and always include any Init Cookie
+                 *            from the Response * /
+                 *        S.state := PARTOPEN
+                 *        Set PARTOPEN timer
+                 *        Continue with S.state == PARTOPEN
+                 *        / * Step 12 will send the Ack completing the
+                 *            three-way handshake * /
+                 */
+                dccp_set_state(sk, DCCP_PARTOPEN);
+
+                /* Make sure socket is routed, for correct metrics. */
+                inet_sk_rebuild_header(sk);
+
+                if (!sock_flag(sk, SOCK_DEAD)) {
+                        sk->sk_state_change(sk);
+                        sk_wake_async(sk, 0, POLL_OUT);
+                }
+
+                if (sk->sk_write_pending || icsk->icsk_ack.pingpong ||
+                    icsk->icsk_accept_queue.rskq_defer_accept) {
+                        /* Save one ACK. Data will be ready after
+                         * several ticks, if write_pending is set.
+                         *
+                         * It may be deleted, but with this feature tcpdumps
+                         * look so _wonderfully_ clever, that I was not able
+                         * to stand against the temptation 8)     --ANK
+                         */
+                        /*
+                         * OK, in DCCP we can as well do a similar trick, its
+                         * even in the draft, but there is no need for us to
+                         * schedule an ack here, as dccp_sendmsg does this for
+                         * us, also stated in the draft. -acme
+                         */
+                        __kfree_skb(skb);
+                        return 0;
+                } 
+                dccp_send_ack(sk);
+                return -1;
+        }
+
+out_invalid_packet:
+        return 1; /* dccp_v4_do_rcv will send a reset, but...
+                     FIXME: the reset code should be
+                            DCCP_RESET_CODE_PACKET_ERROR */
+}
+
+static int dccp_rcv_respond_partopen_state_process(struct sock *sk,
+                                                   struct sk_buff *skb,
+                                                   const struct dccp_hdr *dh,
+                                                   const unsigned len)
+{
+        int queued = 0;
+
+        switch (dh->dccph_type) {
+        case DCCP_PKT_RESET:
+                inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
+                break;
+        case DCCP_PKT_DATAACK:
+        case DCCP_PKT_ACK:
+                /*
+                 * FIXME: we should be reseting the PARTOPEN (DELACK) timer
+                 * here but only if we haven't used the DELACK timer for
+                 * something else, like sending a delayed ack for a TIMESTAMP
+                 * echo, etc, for now were not clearing it, sending an extra
+                 * ACK when there is nothing else to do in DELACK is not a big
+                 * deal after all.
+                 */
+
+                /* Stop the PARTOPEN timer */
+                if (sk->sk_state == DCCP_PARTOPEN)
+                        inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
+
+                dccp_sk(sk)->dccps_osr = DCCP_SKB_CB(skb)->dccpd_seq;
+                dccp_set_state(sk, DCCP_OPEN);
+
+                if (dh->dccph_type == DCCP_PKT_DATAACK) {
+                        dccp_rcv_established(sk, skb, dh, len);
+                        queued = 1; /* packet was queued
+                                       (by dccp_rcv_established) */
+                }
+                break;
+        }
+
+        return queued;
+}
+
+int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
+                           struct dccp_hdr *dh, unsigned len)
+{
+        struct dccp_sock *dp = dccp_sk(sk);
+        const int old_state = sk->sk_state;
+        int queued = 0;
+
+        /*
+         *  Step 3: Process LISTEN state
+         *      (Continuing from dccp_v4_do_rcv and dccp_v6_do_rcv)
+         *
+         *     If S.state == LISTEN,
+         *        If P.type == Request or P contains a valid Init Cookie
+         *              option,
+         *           * Must scan the packet's options to check for an Init
+         *              Cookie.  Only the Init Cookie is processed here,
+         *              however; other options are processed in Step 8.  This
+         *              scan need only be performed if the endpoint uses Init
+         *              Cookies *
+         *           * Generate a new socket and switch to that socket *
+         *           Set S := new socket for this port pair
+         *           S.state = RESPOND
+         *           Choose S.ISS (initial seqno) or set from Init Cookie
+         *           Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
+         *           Continue with S.state == RESPOND
+         *           * A Response packet will be generated in Step 11 *
+         *        Otherwise,
+         *           Generate Reset(No Connection) unless P.type == Reset
+         *           Drop packet and return
+         *
+         * NOTE: the check for the packet types is done in
+         *       dccp_rcv_state_process
+         */
+        if (sk->sk_state == DCCP_LISTEN) {
+                if (dh->dccph_type == DCCP_PKT_REQUEST) {
+                        if (dccp_v4_conn_request(sk, skb) < 0)
+                                return 1;
+
+                        /* FIXME: do congestion control initialization */
+                        goto discard;
+                }
+                if (dh->dccph_type == DCCP_PKT_RESET)
+                        goto discard;
+
+                /* Caller (dccp_v4_do_rcv) will send Reset(No Connection)*/
+                return 1;
+        }
+
+        if (sk->sk_state != DCCP_REQUESTING) {
+                if (dccp_check_seqno(sk, skb))
+                        goto discard;
+
+                /*
+                 * Step 8: Process options and mark acknowledgeable
+                 */
+                if (dccp_parse_options(sk, skb))
+                        goto discard;
+
+                if (DCCP_SKB_CB(skb)->dccpd_ack_seq !=
+                    DCCP_PKT_WITHOUT_ACK_SEQ)
+                        dccp_event_ack_recv(sk, skb);
+
+                ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
+                ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb);
+
+                /*
+                 * FIXME: check ECN to see if we should use
+                 * DCCP_ACKPKTS_STATE_ECN_MARKED
+                 */
+                if (dp->dccps_options.dccpo_send_ack_vector) {
+                        if (dccp_ackpkts_add(dp->dccps_hc_rx_ackpkts,
+                                             DCCP_SKB_CB(skb)->dccpd_seq,
+                                             DCCP_ACKPKTS_STATE_RECEIVED))
+                                goto discard;
+                        /*
+                         * FIXME: this activation is probably wrong, have to
+                         * study more TCP delack machinery and how it fits into
+                         * DCCP draft, but for now it kinda "works" 8)
+                         */
+                        if ((dp->dccps_hc_rx_ackpkts->dccpap_ack_seqno ==
+                             DCCP_MAX_SEQNO + 1) &&
+                            !inet_csk_ack_scheduled(sk)) {
+                                inet_csk_schedule_ack(sk);
+                                inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
+                                                          TCP_DELACK_MIN,
+                                                          DCCP_RTO_MAX);
+                        }
+                }
+        }
+
+        /*
+         *  Step 9: Process Reset
+         *      If P.type == Reset,
+         *              Tear down connection
+         *              S.state := TIMEWAIT
+         *              Set TIMEWAIT timer
+         *              Drop packet and return
+        */
+        if (dh->dccph_type == DCCP_PKT_RESET) {
+                /*
+                 * Queue the equivalent of TCP fin so that dccp_recvmsg
+                 * exits the loop
+                 */
+                dccp_fin(sk, skb);
+                dccp_time_wait(sk, DCCP_TIME_WAIT, 0);
+                return 0;
+                /*
+                 *   Step 7: Check for unexpected packet types
+                 *      If (S.is_server and P.type == CloseReq)
+                 *          or (S.is_server and P.type == Response)
+                 *          or (S.is_client and P.type == Request)
+                 *          or (S.state == RESPOND and P.type == Data),
+                 *        Send Sync packet acknowledging P.seqno
+                 *        Drop packet and return
+                 */
+        } else if ((dp->dccps_role != DCCP_ROLE_CLIENT &&
+                    (dh->dccph_type == DCCP_PKT_RESPONSE ||
+                     dh->dccph_type == DCCP_PKT_CLOSEREQ)) ||
+                    (dp->dccps_role == DCCP_ROLE_CLIENT &&
+                     dh->dccph_type == DCCP_PKT_REQUEST) ||
+                    (sk->sk_state == DCCP_RESPOND &&
+                     dh->dccph_type == DCCP_PKT_DATA)) {
+                dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq,
+                               DCCP_PKT_SYNC);
+                goto discard;
+        } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) {
+                dccp_rcv_closereq(sk, skb);
+                goto discard;
+        } else if (dh->dccph_type == DCCP_PKT_CLOSE) {
+                dccp_rcv_close(sk, skb);
+                return 0;
+        }
+
+        switch (sk->sk_state) {
+        case DCCP_CLOSED:
+                return 1;
+
+        case DCCP_REQUESTING:
+                /* FIXME: do congestion control initialization */
+
+                queued = dccp_rcv_request_sent_state_process(sk, skb, dh, len);
+                if (queued >= 0)
+                        return queued;
+
+                __kfree_skb(skb);
+                return 0;
+
+        case DCCP_RESPOND:
+        case DCCP_PARTOPEN:
+                queued = dccp_rcv_respond_partopen_state_process(sk, skb,
+                                                                 dh, len);
+                break;
+        }
+
+        if (dh->dccph_type == DCCP_PKT_ACK ||
+            dh->dccph_type == DCCP_PKT_DATAACK) {
+                switch (old_state) {
+                case DCCP_PARTOPEN:
+                        sk->sk_state_change(sk);
+                        sk_wake_async(sk, 0, POLL_OUT);
+                        break;
+                }
+        }
+
+        if (!queued) { 
+discard:
+                __kfree_skb(skb);
+        }
+        return 0;
+}