[mirror_ubuntu-artful-kernel.git] / net / dccp / input.c

/*
 *  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 "ackvec.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;
	}

	if (sk->sk_state != DCCP_CLOSING)
		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_ackvec_check_rcv_ackno(dp->dccps_hc_rx_ackvec, 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;
}

static inline 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);

	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;
}

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);

	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 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);

	return __dccp_rcv_established(sk, skb, dh, len);
discard:
	__kfree_skb(skb);
	return 0;
}

EXPORT_SYMBOL_GPL(dccp_rcv_established);

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;
		}

		if (dccp_parse_options(sk, skb))
			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 */

		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, icsk->icsk_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. */
		icsk->icsk_af_ops->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:
	/* dccp_v4_do_rcv will send a reset */
	DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
	return 1; 
}

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_DATA:
		if (sk->sk_state == DCCP_RESPOND)
			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 ||
		    dh->dccph_type == DCCP_PKT_DATA) {
			__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);
	struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
	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 (inet_csk(sk)->icsk_af_ops->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 */
		dcb->dccpd_reset_code = DCCP_RESET_CODE_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 (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
			dccp_event_ack_recv(sk, skb);

 		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 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);
	}

	/*
	 *  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, dcb->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;
	}

	if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) {
		dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNCACK);
		goto discard;
	}

	switch (sk->sk_state) {
	case DCCP_CLOSED:
		dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION;
		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;
}

EXPORT_SYMBOL_GPL(dccp_rcv_state_process);
Commit	Line	Data
7c657876 ACM	1	/*
	2	* net/dccp/input.c
	3	*
	4	* An implementation of the DCCP protocol
	5	* Arnaldo Carvalho de Melo <acme@conectiva.com.br>
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License
	9	* as published by the Free Software Foundation; either version
	10	* 2 of the License, or (at your option) any later version.
	11	*/
	12
	13	#include <linux/config.h>
	14	#include <linux/dccp.h>
	15	#include <linux/skbuff.h>
	16
	17	#include <net/sock.h>
	18
ae31c339	19	#include "ackvec.h"
7c657876 ACM	20	#include "ccid.h"
	21	#include "dccp.h"
	22
	23	static void dccp_fin(struct sock sk, struct sk_buff skb)
	24	{
	25	sk->sk_shutdown \|= RCV_SHUTDOWN;
	26	sock_set_flag(sk, SOCK_DONE);
	27	__skb_pull(skb, dccp_hdr(skb)->dccph_doff * 4);
	28	__skb_queue_tail(&sk->sk_receive_queue, skb);
	29	skb_set_owner_r(skb, sk);
	30	sk->sk_data_ready(sk, 0);
	31	}
	32
	33	static void dccp_rcv_close(struct sock sk, struct sk_buff skb)
	34	{
7ad07e7c ACM	35	dccp_v4_send_reset(sk, DCCP_RESET_CODE_CLOSED);
	36	dccp_fin(sk, skb);
	37	dccp_set_state(sk, DCCP_CLOSED);
331968bd	38	sk_wake_async(sk, 1, POLL_HUP);
7c657876 ACM	39	}
	40
	41	static void dccp_rcv_closereq(struct sock sk, struct sk_buff skb)
	42	{
	43	/*
	44	* Step 7: Check for unexpected packet types
	45	* If (S.is_server and P.type == CloseReq)
	46	* Send Sync packet acknowledging P.seqno
	47	* Drop packet and return
	48	*/
	49	if (dccp_sk(sk)->dccps_role != DCCP_ROLE_CLIENT) {
e92ae93a	50	dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC);
7c657876 ACM	51	return;
	52	}
	53
811265b8 ACM	54	if (sk->sk_state != DCCP_CLOSING)
811265b8 ACM	55	dccp_set_state(sk, DCCP_CLOSING);
7ad07e7c	56	dccp_send_close(sk, 0);
7c657876 ACM	57	}
	58
	59	static inline void dccp_event_ack_recv(struct sock sk, struct sk_buff skb)
	60	{
	61	struct dccp_sock *dp = dccp_sk(sk);
	62
	63	if (dp->dccps_options.dccpo_send_ack_vector)
ae31c339 ACM	64	dccp_ackvec_check_rcv_ackno(dp->dccps_hc_rx_ackvec, sk,
ae31c339 ACM	65	DCCP_SKB_CB(skb)->dccpd_ack_seq);
7c657876 ACM	66	}
	67
	68	static int dccp_check_seqno(struct sock sk, struct sk_buff skb)
	69	{
	70	const struct dccp_hdr *dh = dccp_hdr(skb);
	71	struct dccp_sock *dp = dccp_sk(sk);
e92ae93a	72	u64 lswl, lawl;
7c657876 ACM	73
	74	/*
	75	* Step 5: Prepare sequence numbers for Sync
	76	* If P.type == Sync or P.type == SyncAck,
	77	* If S.AWL <= P.ackno <= S.AWH and P.seqno >= S.SWL,
	78	* / * P is valid, so update sequence number variables
	79	* accordingly. After this update, P will pass the tests
	80	* in Step 6. A SyncAck is generated if necessary in
	81	* Step 15 * /
	82	* Update S.GSR, S.SWL, S.SWH
	83	* Otherwise,
	84	* Drop packet and return
	85	*/
	86	if (dh->dccph_type == DCCP_PKT_SYNC \|\|
	87	dh->dccph_type == DCCP_PKT_SYNCACK) {
7690af3f ACM	88	if (between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
7690af3f ACM	89	dp->dccps_awl, dp->dccps_awh) &&
7c657876 ACM	90	!before48(DCCP_SKB_CB(skb)->dccpd_seq, dp->dccps_swl))
	91	dccp_update_gsr(sk, DCCP_SKB_CB(skb)->dccpd_seq);
	92	else
	93	return -1;
e92ae93a ACM	94	}
e92ae93a ACM	95
7c657876 ACM	96	/*
	97	* Step 6: Check sequence numbers
	98	* Let LSWL = S.SWL and LAWL = S.AWL
	99	* If P.type == CloseReq or P.type == Close or P.type == Reset,
	100	* LSWL := S.GSR + 1, LAWL := S.GAR
	101	* If LSWL <= P.seqno <= S.SWH
	102	* and (P.ackno does not exist or LAWL <= P.ackno <= S.AWH),
	103	* Update S.GSR, S.SWL, S.SWH
	104	* If P.type != Sync,
	105	* Update S.GAR
	106	* Otherwise,
	107	* Send Sync packet acknowledging P.seqno
	108	* Drop packet and return
	109	*/
e92ae93a ACM	110	lswl = dp->dccps_swl;
	111	lawl = dp->dccps_awl;
	112
	113	if (dh->dccph_type == DCCP_PKT_CLOSEREQ \|\|
c59eab46 ACM	114	dh->dccph_type == DCCP_PKT_CLOSE \|\|
c59eab46 ACM	115	dh->dccph_type == DCCP_PKT_RESET) {
7c657876 ACM	116	lswl = dp->dccps_gsr;
	117	dccp_inc_seqno(&lswl);
	118	lawl = dp->dccps_gar;
	119	}
	120
	121	if (between48(DCCP_SKB_CB(skb)->dccpd_seq, lswl, dp->dccps_swh) &&
	122	(DCCP_SKB_CB(skb)->dccpd_ack_seq == DCCP_PKT_WITHOUT_ACK_SEQ \|\|
7690af3f ACM	123	between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
7690af3f ACM	124	lawl, dp->dccps_awh))) {
7c657876 ACM	125	dccp_update_gsr(sk, DCCP_SKB_CB(skb)->dccpd_seq);
	126
	127	if (dh->dccph_type != DCCP_PKT_SYNC &&
7690af3f ACM	128	(DCCP_SKB_CB(skb)->dccpd_ack_seq !=
7690af3f ACM	129	DCCP_PKT_WITHOUT_ACK_SEQ))
7c657876 ACM	130	dp->dccps_gar = DCCP_SKB_CB(skb)->dccpd_ack_seq;
7c657876 ACM	131	} else {
a3054d48 ACM	132	LIMIT_NETDEBUG(KERN_WARNING "DCCP: Step 6 failed for %s packet, "
	133	"(LSWL(%llu) <= P.seqno(%llu) <= S.SWH(%llu)) and "
	134	"(P.ackno %s or LAWL(%llu) <= P.ackno(%llu) <= S.AWH(%llu), "
	135	"sending SYNC...\n",
	136	dccp_packet_name(dh->dccph_type),
58e45131 DM	137	(unsigned long long) lswl,
	138	(unsigned long long)
	139	DCCP_SKB_CB(skb)->dccpd_seq,
	140	(unsigned long long) dp->dccps_swh,
a3054d48 ACM	141	(DCCP_SKB_CB(skb)->dccpd_ack_seq ==
a3054d48 ACM	142	DCCP_PKT_WITHOUT_ACK_SEQ) ? "doesn't exist" : "exists",
58e45131 DM	143	(unsigned long long) lawl,
	144	(unsigned long long)
	145	DCCP_SKB_CB(skb)->dccpd_ack_seq,
	146	(unsigned long long) dp->dccps_awh);
e92ae93a	147	dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC);
7c657876 ACM	148	return -1;
	149	}
	150
	151	return 0;
	152	}
	153
709dd3aa AB	154	static inline int __dccp_rcv_established(struct sock sk, struct sk_buff skb,
	155	const struct dccp_hdr *dh,
	156	const unsigned len)
7c657876 ACM	157	{
	158	struct dccp_sock *dp = dccp_sk(sk);
	159
7c657876 ACM	160	switch (dccp_hdr(skb)->dccph_type) {
	161	case DCCP_PKT_DATAACK:
	162	case DCCP_PKT_DATA:
	163	/*
7690af3f ACM	164	* FIXME: check if sk_receive_queue is full, schedule DATA_DROPPED
7690af3f ACM	165	* option if it is.
7c657876 ACM	166	*/
	167	__skb_pull(skb, dh->dccph_doff * 4);
	168	__skb_queue_tail(&sk->sk_receive_queue, skb);
	169	skb_set_owner_r(skb, sk);
	170	sk->sk_data_ready(sk, 0);
	171	return 0;
	172	case DCCP_PKT_ACK:
	173	goto discard;
	174	case DCCP_PKT_RESET:
	175	/*
	176	* Step 9: Process Reset
	177	* If P.type == Reset,
	178	* Tear down connection
	179	* S.state := TIMEWAIT
	180	* Set TIMEWAIT timer
	181	* Drop packet and return
	182	*/
	183	dccp_fin(sk, skb);
	184	dccp_time_wait(sk, DCCP_TIME_WAIT, 0);
	185	return 0;
	186	case DCCP_PKT_CLOSEREQ:
	187	dccp_rcv_closereq(sk, skb);
	188	goto discard;
	189	case DCCP_PKT_CLOSE:
	190	dccp_rcv_close(sk, skb);
	191	return 0;
	192	case DCCP_PKT_REQUEST:
	193	/* Step 7
	194	* or (S.is_server and P.type == Response)
	195	* or (S.is_client and P.type == Request)
	196	* or (S.state >= OPEN and P.type == Request
	197	* and P.seqno >= S.OSR)
	198	* or (S.state >= OPEN and P.type == Response
	199	* and P.seqno >= S.OSR)
	200	* or (S.state == RESPOND and P.type == Data),
	201	* Send Sync packet acknowledging P.seqno
	202	* Drop packet and return
	203	*/
	204	if (dp->dccps_role != DCCP_ROLE_LISTEN)
	205	goto send_sync;
	206	goto check_seq;
	207	case DCCP_PKT_RESPONSE:
	208	if (dp->dccps_role != DCCP_ROLE_CLIENT)
	209	goto send_sync;
	210	check_seq:
	211	if (!before48(DCCP_SKB_CB(skb)->dccpd_seq, dp->dccps_osr)) {
	212	send_sync:
e92ae93a ACM	213	dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq,
e92ae93a ACM	214	DCCP_PKT_SYNC);
7c657876 ACM	215	}
7c657876 ACM	216	break;
e92ae93a ACM	217	case DCCP_PKT_SYNC:
	218	dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq,
	219	DCCP_PKT_SYNCACK);
	220	/*
	221	* From the draft:
	222	*
	223	* As with DCCP-Ack packets, DCCP-Sync and DCCP-SyncAck packets
	224	* MAY have non-zero-length application data areas, whose
	225	* contents * receivers MUST ignore.
	226	*/
	227	goto discard;
7c657876 ACM	228	}
	229
	230	DCCP_INC_STATS_BH(DCCP_MIB_INERRS);
	231	discard:
	232	__kfree_skb(skb);
	233	return 0;
	234	}
	235
709dd3aa AB	236	int dccp_rcv_established(struct sock sk, struct sk_buff skb,
	237	const struct dccp_hdr *dh, const unsigned len)
	238	{
	239	struct dccp_sock *dp = dccp_sk(sk);
	240
	241	if (dccp_check_seqno(sk, skb))
	242	goto discard;
	243
	244	if (dccp_parse_options(sk, skb))
	245	goto discard;
	246
	247	if (DCCP_SKB_CB(skb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
	248	dccp_event_ack_recv(sk, skb);
	249
	250	if (dp->dccps_options.dccpo_send_ack_vector &&
	251	dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,
	252	DCCP_SKB_CB(skb)->dccpd_seq,
	253	DCCP_ACKVEC_STATE_RECEIVED))
	254	goto discard;
	255
	256	ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
	257	ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb);
	258
	259	return __dccp_rcv_established(sk, skb, dh, len);
	260	discard:
	261	__kfree_skb(skb);
	262	return 0;
	263	}
	264
f21e68ca ACM	265	EXPORT_SYMBOL_GPL(dccp_rcv_established);
f21e68ca ACM	266
7c657876 ACM	267	static int dccp_rcv_request_sent_state_process(struct sock *sk,
	268	struct sk_buff *skb,
	269	const struct dccp_hdr *dh,
	270	const unsigned len)
	271	{
	272	/*
	273	* Step 4: Prepare sequence numbers in REQUEST
	274	* If S.state == REQUEST,
	275	* If (P.type == Response or P.type == Reset)
	276	* and S.AWL <= P.ackno <= S.AWH,
	277	* / * Set sequence number variables corresponding to the
	278	* other endpoint, so P will pass the tests in Step 6 * /
	279	* Set S.GSR, S.ISR, S.SWL, S.SWH
	280	* / * Response processing continues in Step 10; Reset
	281	* processing continues in Step 9 * /
	282	*/
	283	if (dh->dccph_type == DCCP_PKT_RESPONSE) {
	284	const struct inet_connection_sock *icsk = inet_csk(sk);
	285	struct dccp_sock *dp = dccp_sk(sk);
	286
	287	/* Stop the REQUEST timer */
	288	inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS);
	289	BUG_TRAP(sk->sk_send_head != NULL);
	290	__kfree_skb(sk->sk_send_head);
	291	sk->sk_send_head = NULL;
	292
7690af3f ACM	293	if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
	294	dp->dccps_awl, dp->dccps_awh)) {
	295	dccp_pr_debug("invalid ackno: S.AWL=%llu, "
	296	"P.ackno=%llu, S.AWH=%llu \n",
	297	(unsigned long long)dp->dccps_awl,
	298	(unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq,
	299	(unsigned long long)dp->dccps_awh);
7c657876 ACM	300	goto out_invalid_packet;
7c657876 ACM	301	}
9e377202	302
afe00251 AB	303	if (dccp_parse_options(sk, skb))
	304	goto out_invalid_packet;
	305
9e377202 AB	306	if (dp->dccps_options.dccpo_send_ack_vector &&
	307	dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,
	308	DCCP_SKB_CB(skb)->dccpd_seq,
	309	DCCP_ACKVEC_STATE_RECEIVED))
	310	goto out_invalid_packet; /* FIXME: change error code */
7c657876 ACM	311
7c657876 ACM	312	dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq;
03ace394 ACM	313	dccp_update_gsr(sk, dp->dccps_isr);
	314	/*
	315	* SWL and AWL are initially adjusted so that they are not less than
	316	* the initial Sequence Numbers received and sent, respectively:
	317	* SWL := max(GSR + 1 - floor(W/4), ISR),
	318	* AWL := max(GSS - W' + 1, ISS).
	319	* These adjustments MUST be applied only at the beginning of the
	320	* connection.
	321	*
	322	* AWL was adjusted in dccp_v4_connect -acme
	323	*/
	324	dccp_set_seqno(&dp->dccps_swl,
	325	max48(dp->dccps_swl, dp->dccps_isr));
7c657876 ACM	326
	327	if (ccid_hc_rx_init(dp->dccps_hc_rx_ccid, sk) != 0 \|\|
	328	ccid_hc_tx_init(dp->dccps_hc_tx_ccid, sk) != 0) {
	329	ccid_hc_rx_exit(dp->dccps_hc_rx_ccid, sk);
	330	ccid_hc_tx_exit(dp->dccps_hc_tx_ccid, sk);
	331	/* FIXME: send appropriate RESET code */
	332	goto out_invalid_packet;
	333	}
	334
d83d8461	335	dccp_sync_mss(sk, icsk->icsk_pmtu_cookie);
7c657876 ACM	336
	337	/*
	338	* Step 10: Process REQUEST state (second part)
	339	* If S.state == REQUEST,
7690af3f ACM	340	* / * If we get here, P is a valid Response from the
	341	* server (see Step 4), and we should move to
	342	* PARTOPEN state. PARTOPEN means send an Ack,
	343	* don't send Data packets, retransmit Acks
	344	* periodically, and always include any Init Cookie
	345	* from the Response * /
7c657876 ACM	346	* S.state := PARTOPEN
	347	* Set PARTOPEN timer
	348	* Continue with S.state == PARTOPEN
7690af3f ACM	349	* / * Step 12 will send the Ack completing the
7690af3f ACM	350	* three-way handshake * /
7c657876 ACM	351	*/
	352	dccp_set_state(sk, DCCP_PARTOPEN);
	353
	354	/* Make sure socket is routed, for correct metrics. */
57cca05a	355	icsk->icsk_af_ops->rebuild_header(sk);
7c657876 ACM	356
	357	if (!sock_flag(sk, SOCK_DEAD)) {
	358	sk->sk_state_change(sk);
	359	sk_wake_async(sk, 0, POLL_OUT);
	360	}
	361
	362	if (sk->sk_write_pending \|\| icsk->icsk_ack.pingpong \|\|
	363	icsk->icsk_accept_queue.rskq_defer_accept) {
	364	/* Save one ACK. Data will be ready after
	365	* several ticks, if write_pending is set.
	366	*
	367	* It may be deleted, but with this feature tcpdumps
	368	* look so _wonderfully_ clever, that I was not able
	369	* to stand against the temptation 8) --ANK
	370	*/
	371	/*
	372	* OK, in DCCP we can as well do a similar trick, its
	373	* even in the draft, but there is no need for us to
	374	* schedule an ack here, as dccp_sendmsg does this for
	375	* us, also stated in the draft. -acme
	376	*/
	377	__kfree_skb(skb);
	378	return 0;
	379	}
	380	dccp_send_ack(sk);
	381	return -1;
	382	}
	383
	384	out_invalid_packet:
0c10c5d9 ACM	385	/* dccp_v4_do_rcv will send a reset */
	386	DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
	387	return 1;
7c657876 ACM	388	}
	389
	390	static int dccp_rcv_respond_partopen_state_process(struct sock *sk,
	391	struct sk_buff *skb,
	392	const struct dccp_hdr *dh,
	393	const unsigned len)
	394	{
	395	int queued = 0;
	396
	397	switch (dh->dccph_type) {
	398	case DCCP_PKT_RESET:
	399	inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
	400	break;
2a9bc9bb ACM	401	case DCCP_PKT_DATA:
	402	if (sk->sk_state == DCCP_RESPOND)
	403	break;
7c657876 ACM	404	case DCCP_PKT_DATAACK:
	405	case DCCP_PKT_ACK:
	406	/*
7690af3f ACM	407	* FIXME: we should be reseting the PARTOPEN (DELACK) timer
	408	* here but only if we haven't used the DELACK timer for
	409	* something else, like sending a delayed ack for a TIMESTAMP
	410	* echo, etc, for now were not clearing it, sending an extra
	411	* ACK when there is nothing else to do in DELACK is not a big
	412	* deal after all.
7c657876 ACM	413	*/
	414
	415	/* Stop the PARTOPEN timer */
	416	if (sk->sk_state == DCCP_PARTOPEN)
	417	inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
	418
	419	dccp_sk(sk)->dccps_osr = DCCP_SKB_CB(skb)->dccpd_seq;
	420	dccp_set_state(sk, DCCP_OPEN);
	421
2a9bc9bb ACM	422	if (dh->dccph_type == DCCP_PKT_DATAACK \|\|
2a9bc9bb ACM	423	dh->dccph_type == DCCP_PKT_DATA) {
709dd3aa	424	__dccp_rcv_established(sk, skb, dh, len);
7690af3f	425	queued = 1; /* packet was queued
709dd3aa	426	(by __dccp_rcv_established) */
7c657876 ACM	427	}
	428	break;
	429	}
	430
	431	return queued;
	432	}
	433
	434	int dccp_rcv_state_process(struct sock sk, struct sk_buff skb,
	435	struct dccp_hdr *dh, unsigned len)
	436	{
	437	struct dccp_sock *dp = dccp_sk(sk);
0c10c5d9	438	struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
7c657876 ACM	439	const int old_state = sk->sk_state;
	440	int queued = 0;
	441
8649b0d4 ACM	442	/*
	443	* Step 3: Process LISTEN state
	444	* (Continuing from dccp_v4_do_rcv and dccp_v6_do_rcv)
	445	*
	446	* If S.state == LISTEN,
	447	* If P.type == Request or P contains a valid Init Cookie
	448	* option,
	449	* * Must scan the packet's options to check for an Init
	450	* Cookie. Only the Init Cookie is processed here,
	451	* however; other options are processed in Step 8. This
	452	* scan need only be performed if the endpoint uses Init
	453	* Cookies *
	454	* * Generate a new socket and switch to that socket *
	455	* Set S := new socket for this port pair
	456	* S.state = RESPOND
	457	* Choose S.ISS (initial seqno) or set from Init Cookie
	458	* Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
	459	* Continue with S.state == RESPOND
	460	* * A Response packet will be generated in Step 11 *
	461	* Otherwise,
	462	* Generate Reset(No Connection) unless P.type == Reset
	463	* Drop packet and return
	464	*
	465	* NOTE: the check for the packet types is done in
	466	* dccp_rcv_state_process
	467	*/
	468	if (sk->sk_state == DCCP_LISTEN) {
	469	if (dh->dccph_type == DCCP_PKT_REQUEST) {
57cca05a ACM	470	if (inet_csk(sk)->icsk_af_ops->conn_request(sk,
57cca05a ACM	471	skb) < 0)
8649b0d4 ACM	472	return 1;
	473
	474	/* FIXME: do congestion control initialization */
	475	goto discard;
	476	}
	477	if (dh->dccph_type == DCCP_PKT_RESET)
	478	goto discard;
	479
0c10c5d9 ACM	480	/* Caller (dccp_v4_do_rcv) will send Reset */
0c10c5d9 ACM	481	dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION;
8649b0d4 ACM	482	return 1;
	483	}
	484
	485	if (sk->sk_state != DCCP_REQUESTING) {
7c657876 ACM	486	if (dccp_check_seqno(sk, skb))
	487	goto discard;
	488
	489	/*
	490	* Step 8: Process options and mark acknowledgeable
	491	*/
	492	if (dccp_parse_options(sk, skb))
	493	goto discard;
	494
0c10c5d9	495	if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
7c657876 ACM	496	dccp_event_ack_recv(sk, skb);
7c657876 ACM	497
ae31c339 ACM	498	if (dp->dccps_options.dccpo_send_ack_vector &&
	499	dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,
	500	DCCP_SKB_CB(skb)->dccpd_seq,
	501	DCCP_ACKVEC_STATE_RECEIVED))
	502	goto discard;
e84a9f5e AB	503
	504	ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
	505	ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb);
7c657876 ACM	506	}
	507
	508	/*
	509	* Step 9: Process Reset
	510	* If P.type == Reset,
	511	* Tear down connection
	512	* S.state := TIMEWAIT
	513	* Set TIMEWAIT timer
	514	* Drop packet and return
	515	*/
	516	if (dh->dccph_type == DCCP_PKT_RESET) {
7690af3f ACM	517	/*
	518	* Queue the equivalent of TCP fin so that dccp_recvmsg
	519	* exits the loop
	520	*/
7c657876 ACM	521	dccp_fin(sk, skb);
	522	dccp_time_wait(sk, DCCP_TIME_WAIT, 0);
	523	return 0;
	524	/*
	525	* Step 7: Check for unexpected packet types
	526	* If (S.is_server and P.type == CloseReq)
	527	* or (S.is_server and P.type == Response)
	528	* or (S.is_client and P.type == Request)
	529	* or (S.state == RESPOND and P.type == Data),
	530	* Send Sync packet acknowledging P.seqno
	531	* Drop packet and return
	532	*/
	533	} else if ((dp->dccps_role != DCCP_ROLE_CLIENT &&
7690af3f ACM	534	(dh->dccph_type == DCCP_PKT_RESPONSE \|\|
7690af3f ACM	535	dh->dccph_type == DCCP_PKT_CLOSEREQ)) \|\|
7c657876 ACM	536	(dp->dccps_role == DCCP_ROLE_CLIENT &&
7c657876 ACM	537	dh->dccph_type == DCCP_PKT_REQUEST) \|\|
7690af3f ACM	538	(sk->sk_state == DCCP_RESPOND &&
7690af3f ACM	539	dh->dccph_type == DCCP_PKT_DATA)) {
0c10c5d9	540	dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNC);
7c657876	541	goto discard;
7ad07e7c ACM	542	} else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) {
	543	dccp_rcv_closereq(sk, skb);
	544	goto discard;
	545	} else if (dh->dccph_type == DCCP_PKT_CLOSE) {
	546	dccp_rcv_close(sk, skb);
	547	return 0;
7c657876 ACM	548	}
7c657876 ACM	549
2b80230a	550	if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) {
0c10c5d9	551	dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNCACK);
2b80230a ACM	552	goto discard;
	553	}
	554
7c657876 ACM	555	switch (sk->sk_state) {
7c657876 ACM	556	case DCCP_CLOSED:
0c10c5d9	557	dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION;
7c657876 ACM	558	return 1;
7c657876 ACM	559
7c657876 ACM	560	case DCCP_REQUESTING:
	561	/* FIXME: do congestion control initialization */
	562
	563	queued = dccp_rcv_request_sent_state_process(sk, skb, dh, len);
	564	if (queued >= 0)
	565	return queued;
	566
	567	__kfree_skb(skb);
	568	return 0;
	569
	570	case DCCP_RESPOND:
	571	case DCCP_PARTOPEN:
7690af3f ACM	572	queued = dccp_rcv_respond_partopen_state_process(sk, skb,
7690af3f ACM	573	dh, len);
7c657876 ACM	574	break;
	575	}
	576
7690af3f ACM	577	if (dh->dccph_type == DCCP_PKT_ACK \|\|
7690af3f ACM	578	dh->dccph_type == DCCP_PKT_DATAACK) {
7c657876 ACM	579	switch (old_state) {
	580	case DCCP_PARTOPEN:
	581	sk->sk_state_change(sk);
	582	sk_wake_async(sk, 0, POLL_OUT);
	583	break;
	584	}
	585	}
	586
	587	if (!queued) {
	588	discard:
	589	__kfree_skb(skb);
	590	}
	591	return 0;
	592	}
f21e68ca ACM	593
f21e68ca ACM	594	EXPORT_SYMBOL_GPL(dccp_rcv_state_process);