示例#1
0
文件: output.c 项目: 274914765/C
/*
 * All SKB's seen here are completely headerless. It is our
 * job to build the DCCP header, and pass the packet down to
 * IP so it can do the same plus pass the packet off to the
 * device.
 */
static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
{
    if (likely(skb != NULL)) {
        const struct inet_sock *inet = inet_sk(sk);
        const struct inet_connection_sock *icsk = inet_csk(sk);
        struct dccp_sock *dp = dccp_sk(sk);
        struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
        struct dccp_hdr *dh;
        /* XXX For now we're using only 48 bits sequence numbers */
        const u32 dccp_header_size = sizeof(*dh) +
                         sizeof(struct dccp_hdr_ext) +
                      dccp_packet_hdr_len(dcb->dccpd_type);
        int err, set_ack = 1;
        u64 ackno = dp->dccps_gsr;

        dccp_inc_seqno(&dp->dccps_gss);

        switch (dcb->dccpd_type) {
        case DCCP_PKT_DATA:
            set_ack = 0;
            /* fall through */
        case DCCP_PKT_DATAACK:
        case DCCP_PKT_RESET:
            break;

        case DCCP_PKT_REQUEST:
            set_ack = 0;
            /* fall through */

        case DCCP_PKT_SYNC:
        case DCCP_PKT_SYNCACK:
            ackno = dcb->dccpd_ack_seq;
            /* fall through */
        default:
            /*
             * Set owner/destructor: some skbs are allocated via
             * alloc_skb (e.g. when retransmission may happen).
             * Only Data, DataAck, and Reset packets should come
             * through here with skb->sk set.
             */
            WARN_ON(skb->sk);
            skb_set_owner_w(skb, sk);
            break;
        }

        dcb->dccpd_seq = dp->dccps_gss;

        if (dccp_insert_options(sk, skb)) {
            kfree_skb(skb);
            return -EPROTO;
        }


        /* Build DCCP header and checksum it. */
        dh = dccp_zeroed_hdr(skb, dccp_header_size);
        dh->dccph_type    = dcb->dccpd_type;
        dh->dccph_sport    = inet->sport;
        dh->dccph_dport    = inet->dport;
        dh->dccph_doff    = (dccp_header_size + dcb->dccpd_opt_len) / 4;
        dh->dccph_ccval    = dcb->dccpd_ccval;
        dh->dccph_cscov = dp->dccps_pcslen;
        /* XXX For now we're using only 48 bits sequence numbers */
        dh->dccph_x    = 1;

        dp->dccps_awh = dp->dccps_gss;
        dccp_hdr_set_seq(dh, dp->dccps_gss);
        if (set_ack)
            dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno);

        switch (dcb->dccpd_type) {
        case DCCP_PKT_REQUEST:
            dccp_hdr_request(skb)->dccph_req_service =
                            dp->dccps_service;
            break;
        case DCCP_PKT_RESET:
            dccp_hdr_reset(skb)->dccph_reset_code =
                            dcb->dccpd_reset_code;
            break;
        }

        icsk->icsk_af_ops->send_check(sk, 0, skb);

        if (set_ack)
            dccp_event_ack_sent(sk);

        DCCP_INC_STATS(DCCP_MIB_OUTSEGS);

        err = icsk->icsk_af_ops->queue_xmit(skb, 0);
        return net_xmit_eval(err);
    }
    return -ENOBUFS;
}
示例#2
0
static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
{
	if (likely(skb != NULL)) {
		const struct inet_sock *inet = inet_sk(sk);
		const struct inet_connection_sock *icsk = inet_csk(sk);
		struct dccp_sock *dp = dccp_sk(sk);
		struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
		struct dccp_hdr *dh;
		
		const u32 dccp_header_size = sizeof(*dh) +
					     sizeof(struct dccp_hdr_ext) +
					  dccp_packet_hdr_len(dcb->dccpd_type);
		int err, set_ack = 1;
		u64 ackno = dp->dccps_gsr;
		
		dcb->dccpd_seq = ADD48(dp->dccps_gss, 1);

		switch (dcb->dccpd_type) {
		case DCCP_PKT_DATA:
			set_ack = 0;
			
		case DCCP_PKT_DATAACK:
		case DCCP_PKT_RESET:
			break;

		case DCCP_PKT_REQUEST:
			set_ack = 0;
			
			if (icsk->icsk_retransmits == 0)
				dcb->dccpd_seq = dp->dccps_iss;
			

		case DCCP_PKT_SYNC:
		case DCCP_PKT_SYNCACK:
			ackno = dcb->dccpd_ack_seq;
			
		default:
			
			WARN_ON(skb->sk);
			skb_set_owner_w(skb, sk);
			break;
		}

		if (dccp_insert_options(sk, skb)) {
			kfree_skb(skb);
			return -EPROTO;
		}


		
		dh = dccp_zeroed_hdr(skb, dccp_header_size);
		dh->dccph_type	= dcb->dccpd_type;
		dh->dccph_sport	= inet->sport;
		dh->dccph_dport	= inet->dport;
		dh->dccph_doff	= (dccp_header_size + dcb->dccpd_opt_len) / 4;
		dh->dccph_ccval	= dcb->dccpd_ccval;
		dh->dccph_cscov = dp->dccps_pcslen;
		
		dh->dccph_x	= 1;

		dccp_update_gss(sk, dcb->dccpd_seq);
		dccp_hdr_set_seq(dh, dp->dccps_gss);
		if (set_ack)
			dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno);

		switch (dcb->dccpd_type) {
		case DCCP_PKT_REQUEST:
			dccp_hdr_request(skb)->dccph_req_service =
							dp->dccps_service;
			
			dp->dccps_awl = dp->dccps_iss;
			break;
		case DCCP_PKT_RESET:
			dccp_hdr_reset(skb)->dccph_reset_code =
							dcb->dccpd_reset_code;
			break;
		}

		icsk->icsk_af_ops->send_check(sk, 0, skb);

		if (set_ack)
			dccp_event_ack_sent(sk);

		DCCP_INC_STATS(DCCP_MIB_OUTSEGS);

		err = icsk->icsk_af_ops->queue_xmit(skb, 0);
		return net_xmit_eval(err);
	}
	return -ENOBUFS;
}
示例#3
0
/*
 * All SKB's seen here are completely headerless. It is our
 * job to build the DCCP header, and pass the packet down to
 * IP so it can do the same plus pass the packet off to the
 * device.
 */
static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
{
	if (likely(skb != NULL)) {
		struct inet_sock *inet = inet_sk(sk);
		const struct inet_connection_sock *icsk = inet_csk(sk);
		struct dccp_sock *dp = dccp_sk(sk);
		struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
		struct dccp_hdr *dh;
		/* XXX For now we're using only 48 bits sequence numbers */
		const u32 dccp_header_size = sizeof(*dh) +
					     sizeof(struct dccp_hdr_ext) +
					  dccp_packet_hdr_len(dcb->dccpd_type);
		int err, set_ack = 1;
		u64 ackno = dp->dccps_gsr;
		/*
		 * Increment GSS here already in case the option code needs it.
		 * Update GSS for real only if option processing below succeeds.
		 */
		dcb->dccpd_seq = ADD48(dp->dccps_gss, 1);

		switch (dcb->dccpd_type) {
		case DCCP_PKT_DATA:
			set_ack = 0;
			/* fall through */
		case DCCP_PKT_DATAACK:
		case DCCP_PKT_RESET:
			break;

		case DCCP_PKT_REQUEST:
			set_ack = 0;
			/* Use ISS on the first (non-retransmitted) Request. */
			if (icsk->icsk_retransmits == 0)
				dcb->dccpd_seq = dp->dccps_iss;
			/* fall through */

		case DCCP_PKT_SYNC:
		case DCCP_PKT_SYNCACK:
			ackno = dcb->dccpd_ack_seq;
			/* fall through */
		default:
			/*
			 * Set owner/destructor: some skbs are allocated via
			 * alloc_skb (e.g. when retransmission may happen).
			 * Only Data, DataAck, and Reset packets should come
			 * through here with skb->sk set.
			 */
			WARN_ON(skb->sk);
			skb_set_owner_w(skb, sk);
			break;
		}

		if (dccp_insert_options(sk, skb)) {
			kfree_skb(skb);
			return -EPROTO;
		}


		/* Build DCCP header and checksum it. */
		dh = dccp_zeroed_hdr(skb, dccp_header_size);
		dh->dccph_type	= dcb->dccpd_type;
		dh->dccph_sport	= inet->inet_sport;
		dh->dccph_dport	= inet->inet_dport;
		dh->dccph_doff	= (dccp_header_size + dcb->dccpd_opt_len) / 4;
		dh->dccph_ccval	= dcb->dccpd_ccval;
		dh->dccph_cscov = dp->dccps_pcslen;
		/* XXX For now we're using only 48 bits sequence numbers */
		dh->dccph_x	= 1;

		dccp_update_gss(sk, dcb->dccpd_seq);
		dccp_hdr_set_seq(dh, dp->dccps_gss);
		if (set_ack)
			dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno);

		switch (dcb->dccpd_type) {
		case DCCP_PKT_REQUEST:
			dccp_hdr_request(skb)->dccph_req_service =
							dp->dccps_service;
			/*
			 * Limit Ack window to ISS <= P.ackno <= GSS, so that
			 * only Responses to Requests we sent are considered.
			 */
			dp->dccps_awl = dp->dccps_iss;
			break;
		case DCCP_PKT_RESET:
			dccp_hdr_reset(skb)->dccph_reset_code =
							dcb->dccpd_reset_code;
			break;
		}

		icsk->icsk_af_ops->send_check(sk, skb);

		if (set_ack)
			dccp_event_ack_sent(sk);

		DCCP_INC_STATS(DCCP_MIB_OUTSEGS);

		err = icsk->icsk_af_ops->queue_xmit(skb, &inet->cork.fl);
		return net_xmit_eval(err);
	}
	return -ENOBUFS;
}
示例#4
0
/*
 * All SKB's seen here are completely headerless. It is our
 * job to build the DCCP header, and pass the packet down to
 * IP so it can do the same plus pass the packet off to the
 * device.
 */
int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
{
	if (likely(skb != NULL)) {
		const struct inet_sock *inet = inet_sk(sk);
		struct dccp_sock *dp = dccp_sk(sk);
		struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
		struct dccp_hdr *dh;
		/* XXX For now we're using only 48 bits sequence numbers */
		const int dccp_header_size = sizeof(*dh) +
					     sizeof(struct dccp_hdr_ext) +
					  dccp_packet_hdr_len(dcb->dccpd_type);
		int err, set_ack = 1;
		u64 ackno = dp->dccps_gsr;

		dccp_inc_seqno(&dp->dccps_gss);

		switch (dcb->dccpd_type) {
		case DCCP_PKT_DATA:
			set_ack = 0;
			break;
		case DCCP_PKT_SYNC:
		case DCCP_PKT_SYNCACK:
			ackno = dcb->dccpd_seq;
			break;
		}

		dcb->dccpd_seq = dp->dccps_gss;
		dccp_insert_options(sk, skb);
		
		skb->h.raw = skb_push(skb, dccp_header_size);
		dh = dccp_hdr(skb);

		if (!skb->sk)
			skb_set_owner_w(skb, sk);

		/* Build DCCP header and checksum it. */
		memset(dh, 0, dccp_header_size);
		dh->dccph_type	= dcb->dccpd_type;
		dh->dccph_sport	= inet->sport;
		dh->dccph_dport	= inet->dport;
		dh->dccph_doff	= (dccp_header_size + dcb->dccpd_opt_len) / 4;
		dh->dccph_ccval	= dcb->dccpd_ccval;
		/* XXX For now we're using only 48 bits sequence numbers */
		dh->dccph_x	= 1;

		dp->dccps_awh = dp->dccps_gss;
		dccp_hdr_set_seq(dh, dp->dccps_gss);
		if (set_ack)
			dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno);

		switch (dcb->dccpd_type) {
		case DCCP_PKT_REQUEST:
			dccp_hdr_request(skb)->dccph_req_service =
							dp->dccps_service;
			break;
		case DCCP_PKT_RESET:
			dccp_hdr_reset(skb)->dccph_reset_code =
							dcb->dccpd_reset_code;
			break;
		}

		dh->dccph_checksum = dccp_v4_checksum(skb, inet->saddr,
						      inet->daddr);

		if (set_ack)
			dccp_event_ack_sent(sk);

		DCCP_INC_STATS(DCCP_MIB_OUTSEGS);

		memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
		err = ip_queue_xmit(skb, 0);
		if (err <= 0)
			return err;

		/* NET_XMIT_CN is special. It does not guarantee,
		 * that this packet is lost. It tells that device
		 * is about to start to drop packets or already
		 * drops some packets of the same priority and
		 * invokes us to send less aggressively.
		 */
		return err == NET_XMIT_CN ? 0 : err;
	}
	return -ENOBUFS;
}