示例#1
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 (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);

	return __dccp_rcv_established(sk, skb, dh, len);
discard:
	__kfree_skb(skb);
	return 0;
}
示例#2
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 (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;

	/*
	 * Deliver to the CCID module in charge.
	 * FIXME: Currently DCCP operates one-directional only, i.e. a listening
	 *        server is not at the same time a connecting client. There is
	 *        not much sense in delivering to both rx/tx sides at the moment
	 *        (only one is active at a time); when moving to bidirectional
	 *        service, this needs to be revised.
	 */
	if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER)
		ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
	else
		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;
}
示例#3
0
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
	 *
	 *     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 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) {
			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 (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;

		/* XXX see the comments in dccp_rcv_established about this */
		if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER)
			ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
		else
			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;
}
示例#4
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;
		}

		if (dccp_parse_options(sk, skb))
			goto out_invalid_packet;

                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);
		/*
		 * 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));

		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;
}