net: convert BUG_TRAP to generic WARN_ON
[linux-3.10.git] / net / dccp / input.c
index cb0f5c9..df2f110 100644 (file)
@@ -1,6 +1,6 @@
 /*
  *  net/dccp/input.c
- * 
+ *
  *  An implementation of the DCCP protocol
  *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  *
@@ -10,7 +10,6 @@
  *     2 of the License, or (at your option) any later version.
  */
 
-#include <linux/config.h>
 #include <linux/dccp.h>
 #include <linux/skbuff.h>
 
 #include "ccid.h"
 #include "dccp.h"
 
-static void dccp_fin(struct sock *sk, struct sk_buff *skb)
+/* rate-limit for syncs in reply to sequence-invalid packets; RFC 4340, 7.5.4 */
+int sysctl_dccp_sync_ratelimit __read_mostly = HZ / 8;
+
+static void dccp_enqueue_skb(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)
+static void dccp_fin(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);
+       /*
+        * On receiving Close/CloseReq, both RD/WR shutdown are performed.
+        * RFC 4340, 8.3 says that we MAY send further Data/DataAcks after
+        * receiving the closing segment, but there is no guarantee that such
+        * data will be processed at all.
+        */
+       sk->sk_shutdown = SHUTDOWN_MASK;
+       sock_set_flag(sk, SOCK_DONE);
+       dccp_enqueue_skb(sk, skb);
+}
+
+static int dccp_rcv_close(struct sock *sk, struct sk_buff *skb)
+{
+       int queued = 0;
+
+       switch (sk->sk_state) {
+       /*
+        * We ignore Close when received in one of the following states:
+        *  - CLOSED            (may be a late or duplicate packet)
+        *  - PASSIVE_CLOSEREQ  (the peer has sent a CloseReq earlier)
+        *  - RESPOND           (already handled by dccp_check_req)
+        */
+       case DCCP_CLOSING:
+               /*
+                * Simultaneous-close: receiving a Close after sending one. This
+                * can happen if both client and server perform active-close and
+                * will result in an endless ping-pong of crossing and retrans-
+                * mitted Close packets, which only terminates when one of the
+                * nodes times out (min. 64 seconds). Quicker convergence can be
+                * achieved when one of the nodes acts as tie-breaker.
+                * This is ok as both ends are done with data transfer and each
+                * end is just waiting for the other to acknowledge termination.
+                */
+               if (dccp_sk(sk)->dccps_role != DCCP_ROLE_CLIENT)
+                       break;
+               /* fall through */
+       case DCCP_REQUESTING:
+       case DCCP_ACTIVE_CLOSEREQ:
+               dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED);
+               dccp_done(sk);
+               break;
+       case DCCP_OPEN:
+       case DCCP_PARTOPEN:
+               /* Give waiting application a chance to read pending data */
+               queued = 1;
+               dccp_fin(sk, skb);
+               dccp_set_state(sk, DCCP_PASSIVE_CLOSE);
+               /* fall through */
+       case DCCP_PASSIVE_CLOSE:
+               /*
+                * Retransmitted Close: we have already enqueued the first one.
+                */
+               sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP);
+       }
+       return queued;
 }
 
-static void dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb)
+static int dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb)
 {
+       int queued = 0;
+
        /*
         *   Step 7: Check for unexpected packet types
         *      If (S.is_server and P.type == CloseReq)
@@ -48,28 +101,94 @@ static void dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb)
         */
        if (dccp_sk(sk)->dccps_role != DCCP_ROLE_CLIENT) {
                dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC);
-               return;
+               return queued;
        }
 
-       if (sk->sk_state != DCCP_CLOSING)
+       /* Step 13: process relevant Client states < CLOSEREQ */
+       switch (sk->sk_state) {
+       case DCCP_REQUESTING:
+               dccp_send_close(sk, 0);
                dccp_set_state(sk, DCCP_CLOSING);
-       dccp_send_close(sk, 0);
+               break;
+       case DCCP_OPEN:
+       case DCCP_PARTOPEN:
+               /* Give waiting application a chance to read pending data */
+               queued = 1;
+               dccp_fin(sk, skb);
+               dccp_set_state(sk, DCCP_PASSIVE_CLOSEREQ);
+               /* fall through */
+       case DCCP_PASSIVE_CLOSEREQ:
+               sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP);
+       }
+       return queued;
+}
+
+static u8 dccp_reset_code_convert(const u8 code)
+{
+       const u8 error_code[] = {
+       [DCCP_RESET_CODE_CLOSED]             = 0,       /* normal termination */
+       [DCCP_RESET_CODE_UNSPECIFIED]        = 0,       /* nothing known */
+       [DCCP_RESET_CODE_ABORTED]            = ECONNRESET,
+
+       [DCCP_RESET_CODE_NO_CONNECTION]      = ECONNREFUSED,
+       [DCCP_RESET_CODE_CONNECTION_REFUSED] = ECONNREFUSED,
+       [DCCP_RESET_CODE_TOO_BUSY]           = EUSERS,
+       [DCCP_RESET_CODE_AGGRESSION_PENALTY] = EDQUOT,
+
+       [DCCP_RESET_CODE_PACKET_ERROR]       = ENOMSG,
+       [DCCP_RESET_CODE_BAD_INIT_COOKIE]    = EBADR,
+       [DCCP_RESET_CODE_BAD_SERVICE_CODE]   = EBADRQC,
+       [DCCP_RESET_CODE_OPTION_ERROR]       = EILSEQ,
+       [DCCP_RESET_CODE_MANDATORY_ERROR]    = EOPNOTSUPP,
+       };
+
+       return code >= DCCP_MAX_RESET_CODES ? 0 : error_code[code];
+}
+
+static void dccp_rcv_reset(struct sock *sk, struct sk_buff *skb)
+{
+       u8 err = dccp_reset_code_convert(dccp_hdr_reset(skb)->dccph_reset_code);
+
+       sk->sk_err = err;
+
+       /* Queue the equivalent of TCP fin so that dccp_recvmsg exits the loop */
+       dccp_fin(sk, skb);
+
+       if (err && !sock_flag(sk, SOCK_DEAD))
+               sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
+       dccp_time_wait(sk, DCCP_TIME_WAIT, 0);
 }
 
-static inline void dccp_event_ack_recv(struct sock *sk, struct sk_buff *skb)
+static 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)
+       if (dccp_msk(sk)->dccpms_send_ack_vector)
                dccp_ackvec_check_rcv_ackno(dp->dccps_hc_rx_ackvec, sk,
                                            DCCP_SKB_CB(skb)->dccpd_ack_seq);
 }
 
+static void dccp_deliver_input_to_ccids(struct sock *sk, struct sk_buff *skb)
+{
+       const struct dccp_sock *dp = dccp_sk(sk);
+
+       /* Don't deliver to RX CCID when node has shut down read end. */
+       if (!(sk->sk_shutdown & RCV_SHUTDOWN))
+               ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
+       /*
+        * Until the TX queue has been drained, we can not honour SHUT_WR, since
+        * we need received feedback as input to adjust congestion control.
+        */
+       if (sk->sk_write_queue.qlen > 0 || !(sk->sk_shutdown & SEND_SHUTDOWN))
+               ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb);
+}
+
 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;
+       u64 lswl, lawl, seqno = DCCP_SKB_CB(skb)->dccpd_seq,
+                       ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
 
        /*
         *   Step 5: Prepare sequence numbers for Sync
@@ -83,16 +202,15 @@ static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb)
         *        Otherwise,
         *           Drop packet and return
         */
-       if (dh->dccph_type == DCCP_PKT_SYNC || 
+       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);
+               if (between48(ackno, dp->dccps_awl, dp->dccps_awh) &&
+                   dccp_delta_seqno(dp->dccps_swl, seqno) >= 0)
+                       dccp_update_gsr(sk, seqno);
                else
                        return -1;
        }
-       
+
        /*
         *   Step 6: Check sequence numbers
         *      Let LSWL = S.SWL and LAWL = S.AWL
@@ -103,9 +221,6 @@ static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb)
         *        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;
@@ -113,47 +228,60 @@ static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb)
        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);
+               lswl = ADD48(dp->dccps_gsr, 1);
                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 (between48(seqno, lswl, dp->dccps_swh) &&
+           (ackno == DCCP_PKT_WITHOUT_ACK_SEQ ||
+            between48(ackno, lawl, dp->dccps_awh))) {
+               dccp_update_gsr(sk, seqno);
 
                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;
+                   (ackno != DCCP_PKT_WITHOUT_ACK_SEQ))
+                       dp->dccps_gar = ackno;
        } 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);
+               unsigned long now = jiffies;
+               /*
+                *   Step 6: Check sequence numbers
+                *      Otherwise,
+                *         If P.type == Reset,
+                *            Send Sync packet acknowledging S.GSR
+                *         Otherwise,
+                *            Send Sync packet acknowledging P.seqno
+                *      Drop packet and return
+                *
+                *   These Syncs are rate-limited as per RFC 4340, 7.5.4:
+                *   at most 1 / (dccp_sync_rate_limit * HZ) Syncs per second.
+                */
+               if (time_before(now, (dp->dccps_rate_last +
+                                     sysctl_dccp_sync_ratelimit)))
+                       return 0;
+
+               DCCP_WARN("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) seqno,
+                         (unsigned long long) dp->dccps_swh,
+                         (ackno == DCCP_PKT_WITHOUT_ACK_SEQ) ? "doesn't exist"
+                                                             : "exists",
+                         (unsigned long long) lawl, (unsigned long long) ackno,
+                         (unsigned long long) dp->dccps_awh);
+
+               dp->dccps_rate_last = now;
+
+               if (dh->dccph_type == DCCP_PKT_RESET)
+                       seqno = dp->dccps_gsr;
+               dccp_send_sync(sk, seqno, DCCP_PKT_SYNC);
                return -1;
        }
 
        return 0;
 }
 
-static inline int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
-                                        const struct dccp_hdr *dh,
-                                        const unsigned len)
+static 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);
 
@@ -161,13 +289,11 @@ static inline int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
        case DCCP_PKT_DATAACK:
        case DCCP_PKT_DATA:
                /*
-                * FIXME: check if sk_receive_queue is full, schedule DATA_DROPPED
-                * option if it is.
+                * FIXME: schedule DATA_DROPPED (RFC 4340, 11.7.2) if and when
+                * - sk_shutdown == RCV_SHUTDOWN, use Code 1, "Not Listening"
+                * - sk_receive_queue is full, use Code 2, "Receive Buffer"
                 */
-               __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);
+               dccp_enqueue_skb(sk, skb);
                return 0;
        case DCCP_PKT_ACK:
                goto discard;
@@ -179,19 +305,20 @@ static inline int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
                 *              S.state := TIMEWAIT
                 *              Set TIMEWAIT timer
                 *              Drop packet and return
-               */
-               dccp_fin(sk, skb);
-               dccp_time_wait(sk, DCCP_TIME_WAIT, 0);
+                */
+               dccp_rcv_reset(sk, skb);
                return 0;
        case DCCP_PKT_CLOSEREQ:
-               dccp_rcv_closereq(sk, skb);
+               if (dccp_rcv_closereq(sk, skb))
+                       return 0;
                goto discard;
        case DCCP_PKT_CLOSE:
-               dccp_rcv_close(sk, skb);
-               return 0;
+               if (dccp_rcv_close(sk, skb))
+                       return 0;
+               goto discard;
        case DCCP_PKT_REQUEST:
-               /* Step 7 
-                *   or (S.is_server and P.type == Response)
+               /* 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)
@@ -208,7 +335,8 @@ static inline int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
                if (dp->dccps_role != DCCP_ROLE_CLIENT)
                        goto send_sync;
 check_seq:
-               if (!before48(DCCP_SKB_CB(skb)->dccpd_seq, dp->dccps_osr)) {
+               if (dccp_delta_seqno(dp->dccps_osr,
+                                    DCCP_SKB_CB(skb)->dccpd_seq) >= 0) {
 send_sync:
                        dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq,
                                       DCCP_PKT_SYNC);
@@ -218,11 +346,11 @@ send_sync:
                dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq,
                               DCCP_PKT_SYNCACK);
                /*
-                * From the draft:
+                * From RFC 4340, sec. 5.7
                 *
                 * As with DCCP-Ack packets, DCCP-Sync and DCCP-SyncAck packets
                 * MAY have non-zero-length application data areas, whose
-                * contents * receivers MUST ignore.
+                * contents receivers MUST ignore.
                 */
                goto discard;
        }
@@ -241,20 +369,18 @@ int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
        if (dccp_check_seqno(sk, skb))
                goto discard;
 
-       if (dccp_parse_options(sk, skb))
+       if (dccp_parse_options(sk, NULL, skb))
                goto discard;
 
        if (DCCP_SKB_CB(skb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
                dccp_event_ack_recv(sk, skb);
 
-       if (dp->dccps_options.dccpo_send_ack_vector &&
+       if (dccp_msk(sk)->dccpms_send_ack_vector &&
            dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,
                            DCCP_SKB_CB(skb)->dccpd_seq,
                            DCCP_ACKVEC_STATE_RECEIVED))
                goto discard;
-
-       ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
-       ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb);
+       dccp_deliver_input_to_ccids(sk, skb);
 
        return __dccp_rcv_established(sk, skb, dh, len);
 discard:
@@ -269,7 +395,7 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
                                               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)
@@ -283,10 +409,11 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
        if (dh->dccph_type == DCCP_PKT_RESPONSE) {
                const struct inet_connection_sock *icsk = inet_csk(sk);
                struct dccp_sock *dp = dccp_sk(sk);
+               long tstamp = dccp_timestamp();
 
                /* Stop the REQUEST timer */
                inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS);
-               BUG_TRAP(sk->sk_send_head != NULL);
+               WARN_ON(sk->sk_send_head == NULL);
                __kfree_skb(sk->sk_send_head);
                sk->sk_send_head = NULL;
 
@@ -300,11 +427,19 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
                        goto out_invalid_packet;
                }
 
-                if (dp->dccps_options.dccpo_send_ack_vector &&
-                    dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,
-                                    DCCP_SKB_CB(skb)->dccpd_seq,
-                                    DCCP_ACKVEC_STATE_RECEIVED))
-                        goto out_invalid_packet; /* FIXME: change error code */
+               if (dccp_parse_options(sk, NULL, skb))
+                       goto out_invalid_packet;
+
+               /* Obtain usec RTT sample from SYN exchange (used by CCID 3) */
+               if (likely(dp->dccps_options_received.dccpor_timestamp_echo))
+                       dp->dccps_syn_rtt = dccp_sample_rtt(sk, 10 * (tstamp -
+                           dp->dccps_options_received.dccpor_timestamp_echo));
+
+               if (dccp_msk(sk)->dccpms_send_ack_vector &&
+                   dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,
+                                   DCCP_SKB_CB(skb)->dccpd_seq,
+                                   DCCP_ACKVEC_STATE_RECEIVED))
+                       goto out_invalid_packet; /* FIXME: change error code */
 
                dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq;
                dccp_update_gsr(sk, dp->dccps_isr);
@@ -321,14 +456,6 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
                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, icsk->icsk_pmtu_cookie);
 
                /*
@@ -342,7 +469,7 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
                 *            from the Response * /
                 *        S.state := PARTOPEN
                 *        Set PARTOPEN timer
-                *        Continue with S.state == PARTOPEN
+                *        Continue with S.state == PARTOPEN
                 *        / * Step 12 will send the Ack completing the
                 *            three-way handshake * /
                 */
@@ -353,7 +480,7 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
 
                if (!sock_flag(sk, SOCK_DEAD)) {
                        sk->sk_state_change(sk);
-                       sk_wake_async(sk, 0, POLL_OUT);
+                       sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT);
                }
 
                if (sk->sk_write_pending || icsk->icsk_ack.pingpong ||
@@ -373,7 +500,7 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
                         */
                        __kfree_skb(skb);
                        return 0;
-               } 
+               }
                dccp_send_ack(sk);
                return -1;
        }
@@ -381,7 +508,7 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
 out_invalid_packet:
        /* dccp_v4_do_rcv will send a reset */
        DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
-       return 1; 
+       return 1;
 }
 
 static int dccp_rcv_respond_partopen_state_process(struct sock *sk,
@@ -438,29 +565,25 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 
        /*
         *  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 P.type == Request or P contains a valid Init Cookie option,
+        *            (* Must scan the packet's options to check for Init
+        *               Cookies.  Only Init Cookies are 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 Cookies
+        *            Initialize S.GAR := S.ISS
+        *            Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init
+        *            Cookies 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
         */
        if (sk->sk_state == DCCP_LISTEN) {
                if (dh->dccph_type == DCCP_PKT_REQUEST) {
@@ -486,20 +609,19 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
                /*
                 * Step 8: Process options and mark acknowledgeable
                 */
-               if (dccp_parse_options(sk, skb))
+               if (dccp_parse_options(sk, NULL, skb))
                        goto discard;
 
                if (dcb->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);
-
-               if (dp->dccps_options.dccpo_send_ack_vector &&
+               if (dccp_msk(sk)->dccpms_send_ack_vector &&
                    dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,
-                                   DCCP_SKB_CB(skb)->dccpd_seq,
-                                   DCCP_ACKVEC_STATE_RECEIVED))
-                       goto discard;
+                                   DCCP_SKB_CB(skb)->dccpd_seq,
+                                   DCCP_ACKVEC_STATE_RECEIVED))
+                       goto discard;
+
+               dccp_deliver_input_to_ccids(sk, skb);
        }
 
        /*
@@ -511,25 +633,18 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
         *              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);
+               dccp_rcv_reset(sk, skb);
                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)
+                *      If (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)) ||
+                   dh->dccph_type == DCCP_PKT_RESPONSE) ||
                    (dp->dccps_role == DCCP_ROLE_CLIENT &&
                     dh->dccph_type == DCCP_PKT_REQUEST) ||
                    (sk->sk_state == DCCP_RESPOND &&
@@ -537,15 +652,12 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
                dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNC);
                goto discard;
        } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) {
-               dccp_rcv_closereq(sk, skb);
+               if (dccp_rcv_closereq(sk, skb))
+                       return 0;
                goto discard;
        } else if (dh->dccph_type == DCCP_PKT_CLOSE) {
-               dccp_rcv_close(sk, skb);
-               return 0;
-       }
-
-       if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) {
-               dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNCACK);
+               if (dccp_rcv_close(sk, skb))
+                       return 0;
                goto discard;
        }
 
@@ -576,12 +688,15 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
                switch (old_state) {
                case DCCP_PARTOPEN:
                        sk->sk_state_change(sk);
-                       sk_wake_async(sk, 0, POLL_OUT);
+                       sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT);
                        break;
                }
+       } else if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) {
+               dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNCACK);
+               goto discard;
        }
 
-       if (!queued) { 
+       if (!queued) {
 discard:
                __kfree_skb(skb);
        }
@@ -589,3 +704,28 @@ discard:
 }
 
 EXPORT_SYMBOL_GPL(dccp_rcv_state_process);
+
+/**
+ *  dccp_sample_rtt  -  Validate and finalise computation of RTT sample
+ *  @delta:    number of microseconds between packet and acknowledgment
+ *  The routine is kept generic to work in different contexts. It should be
+ *  called immediately when the ACK used for the RTT sample arrives.
+ */
+u32 dccp_sample_rtt(struct sock *sk, long delta)
+{
+       /* dccpor_elapsed_time is either zeroed out or set and > 0 */
+       delta -= dccp_sk(sk)->dccps_options_received.dccpor_elapsed_time * 10;
+
+       if (unlikely(delta <= 0)) {
+               DCCP_WARN("unusable RTT sample %ld, using min\n", delta);
+               return DCCP_SANE_RTT_MIN;
+       }
+       if (unlikely(delta > DCCP_SANE_RTT_MAX)) {
+               DCCP_WARN("RTT sample %ld too large, using max\n", delta);
+               return DCCP_SANE_RTT_MAX;
+       }
+
+       return delta;
+}
+
+EXPORT_SYMBOL_GPL(dccp_sample_rtt);