示例#1
0
文件: output.c 项目: Chong-Li/cse522
struct sk_buff *dccp_make_response(const struct sock *sk, struct dst_entry *dst,
				   struct request_sock *req)
{
	struct dccp_hdr *dh;
	struct dccp_request_sock *dreq;
	const u32 dccp_header_size = sizeof(struct dccp_hdr) +
				     sizeof(struct dccp_hdr_ext) +
				     sizeof(struct dccp_hdr_response);
	struct sk_buff *skb;

	/* sk is marked const to clearly express we dont hold socket lock.
	 * sock_wmalloc() will atomically change sk->sk_wmem_alloc,
	 * it is safe to promote sk to non const.
	 */
	skb = sock_wmalloc((struct sock *)sk, MAX_DCCP_HEADER, 1,
			   GFP_ATOMIC);
	if (!skb)
		return NULL;

	skb_reserve(skb, MAX_DCCP_HEADER);

	skb_dst_set(skb, dst_clone(dst));

	dreq = dccp_rsk(req);
	if (inet_rsk(req)->acked)	/* increase GSS upon retransmission */
		dccp_inc_seqno(&dreq->dreq_gss);
	DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE;
	DCCP_SKB_CB(skb)->dccpd_seq  = dreq->dreq_gss;

	/* Resolve feature dependencies resulting from choice of CCID */
	if (dccp_feat_server_ccid_dependencies(dreq))
		goto response_failed;

	if (dccp_insert_options_rsk(dreq, skb))
		goto response_failed;

	/* Build and checksum header */
	dh = dccp_zeroed_hdr(skb, dccp_header_size);

	dh->dccph_sport	= htons(inet_rsk(req)->ir_num);
	dh->dccph_dport	= inet_rsk(req)->ir_rmt_port;
	dh->dccph_doff	= (dccp_header_size +
			   DCCP_SKB_CB(skb)->dccpd_opt_len) / 4;
	dh->dccph_type	= DCCP_PKT_RESPONSE;
	dh->dccph_x	= 1;
	dccp_hdr_set_seq(dh, dreq->dreq_gss);
	dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_gsr);
	dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service;

	dccp_csum_outgoing(skb);

	/* We use `acked' to remember that a Response was already sent. */
	inet_rsk(req)->acked = 1;
	DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
	return skb;
response_failed:
	kfree_skb(skb);
	return NULL;
}
示例#2
0
struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
				   struct request_sock *req)
{
	struct dccp_hdr *dh;
	struct dccp_request_sock *dreq;
	const u32 dccp_header_size = sizeof(struct dccp_hdr) +
				     sizeof(struct dccp_hdr_ext) +
				     sizeof(struct dccp_hdr_response);
	struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1,
					   GFP_ATOMIC);
	if (skb == NULL)
		return NULL;

	/* Reserve space for headers. */
	skb_reserve(skb, sk->sk_prot->max_header);

	skb_dst_set(skb, dst_clone(dst));

	dreq = dccp_rsk(req);
	if (inet_rsk(req)->acked)	/* increase ISS upon retransmission */
		dccp_inc_seqno(&dreq->dreq_iss);
	DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE;
	DCCP_SKB_CB(skb)->dccpd_seq  = dreq->dreq_iss;

	/* Resolve feature dependencies resulting from choice of CCID */
	if (dccp_feat_server_ccid_dependencies(dreq))
		goto response_failed;

	if (dccp_insert_options_rsk(dreq, skb))
		goto response_failed;

	/* Build and checksum header */
	dh = dccp_zeroed_hdr(skb, dccp_header_size);

	dh->dccph_sport	= inet_rsk(req)->loc_port;
	dh->dccph_dport	= inet_rsk(req)->rmt_port;
	dh->dccph_doff	= (dccp_header_size +
			   DCCP_SKB_CB(skb)->dccpd_opt_len) / 4;
	dh->dccph_type	= DCCP_PKT_RESPONSE;
	dh->dccph_x	= 1;
	dccp_hdr_set_seq(dh, dreq->dreq_iss);
	dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_isr);
	dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service;

	dccp_csum_outgoing(skb);

	/* We use `acked' to remember that a Response was already sent. */
	inet_rsk(req)->acked = 1;
	DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
	return skb;
response_failed:
	kfree_skb(skb);
	return NULL;
}
示例#3
0
struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
				   struct request_sock *req)
{
	struct dccp_hdr *dh;
	struct dccp_request_sock *dreq;
	const u32 dccp_header_size = sizeof(struct dccp_hdr) +
				     sizeof(struct dccp_hdr_ext) +
				     sizeof(struct dccp_hdr_response);
	struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1,
					   GFP_ATOMIC);
	if (skb == NULL)
		return NULL;

	
	skb_reserve(skb, sk->sk_prot->max_header);

	skb_dst_set(skb, dst_clone(dst));

	dreq = dccp_rsk(req);
	if (inet_rsk(req)->acked)	
		dccp_inc_seqno(&dreq->dreq_iss);
	DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE;
	DCCP_SKB_CB(skb)->dccpd_seq  = dreq->dreq_iss;

	
	if (dccp_feat_server_ccid_dependencies(dreq))
		goto response_failed;

	if (dccp_insert_options_rsk(dreq, skb))
		goto response_failed;

	
	dh = dccp_zeroed_hdr(skb, dccp_header_size);

	dh->dccph_sport	= inet_rsk(req)->loc_port;
	dh->dccph_dport	= inet_rsk(req)->rmt_port;
	dh->dccph_doff	= (dccp_header_size +
			   DCCP_SKB_CB(skb)->dccpd_opt_len) / 4;
	dh->dccph_type	= DCCP_PKT_RESPONSE;
	dh->dccph_x	= 1;
	dccp_hdr_set_seq(dh, dreq->dreq_iss);
	dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_isr);
	dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service;

	dccp_csum_outgoing(skb);

	
	inet_rsk(req)->acked = 1;
	DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
	return skb;
response_failed:
	kfree_skb(skb);
	return NULL;
}
示例#4
0
文件: output.c 项目: 274914765/C
/* answer offending packet in @rcv_skb with Reset from control socket @ctl */
struct sk_buff *dccp_ctl_make_reset(struct sock *sk, struct sk_buff *rcv_skb)
{
    struct dccp_hdr *rxdh = dccp_hdr(rcv_skb), *dh;
    struct dccp_skb_cb *dcb = DCCP_SKB_CB(rcv_skb);
    const u32 dccp_hdr_reset_len = sizeof(struct dccp_hdr) +
                       sizeof(struct dccp_hdr_ext) +
                       sizeof(struct dccp_hdr_reset);
    struct dccp_hdr_reset *dhr;
    struct sk_buff *skb;

    skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC);
    if (skb == NULL)
        return NULL;

    skb_reserve(skb, sk->sk_prot->max_header);

    /* Swap the send and the receive. */
    dh = dccp_zeroed_hdr(skb, dccp_hdr_reset_len);
    dh->dccph_type    = DCCP_PKT_RESET;
    dh->dccph_sport    = rxdh->dccph_dport;
    dh->dccph_dport    = rxdh->dccph_sport;
    dh->dccph_doff    = dccp_hdr_reset_len / 4;
    dh->dccph_x    = 1;

    dhr = dccp_hdr_reset(skb);
    dhr->dccph_reset_code = dcb->dccpd_reset_code;

    switch (dcb->dccpd_reset_code) {
    case DCCP_RESET_CODE_PACKET_ERROR:
        dhr->dccph_reset_data[0] = rxdh->dccph_type;
        break;
    case DCCP_RESET_CODE_OPTION_ERROR:    /* fall through */
    case DCCP_RESET_CODE_MANDATORY_ERROR:
        memcpy(dhr->dccph_reset_data, dcb->dccpd_reset_data, 3);
        break;
    }
    /*
     * From RFC 4340, 8.3.1:
     *   If P.ackno exists, set R.seqno := P.ackno + 1.
     *   Else set R.seqno := 0.
     */
    if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
        dccp_hdr_set_seq(dh, ADD48(dcb->dccpd_ack_seq, 1));
    dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dcb->dccpd_seq);

    dccp_csum_outgoing(skb);
    return skb;
}
示例#5
0
static struct sk_buff *dccp_make_reset(struct sock *sk, struct dst_entry *dst,
				       const enum dccp_reset_codes code)
{
	struct dccp_hdr *dh;
	struct dccp_sock *dp = dccp_sk(sk);
	const u32 dccp_header_size = sizeof(struct dccp_hdr) +
				     sizeof(struct dccp_hdr_ext) +
				     sizeof(struct dccp_hdr_reset);
	struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1,
					   GFP_ATOMIC);
	if (skb == NULL)
		return NULL;

	/* Reserve space for headers. */
	skb_reserve(skb, sk->sk_prot->max_header);

	skb->dst = dst_clone(dst);

	dccp_inc_seqno(&dp->dccps_gss);

	DCCP_SKB_CB(skb)->dccpd_reset_code = code;
	DCCP_SKB_CB(skb)->dccpd_type	   = DCCP_PKT_RESET;
	DCCP_SKB_CB(skb)->dccpd_seq	   = dp->dccps_gss;

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

	dh = dccp_zeroed_hdr(skb, dccp_header_size);

	dh->dccph_sport	= inet_sk(sk)->sport;
	dh->dccph_dport	= inet_sk(sk)->dport;
	dh->dccph_doff	= (dccp_header_size +
			   DCCP_SKB_CB(skb)->dccpd_opt_len) / 4;
	dh->dccph_type	= DCCP_PKT_RESET;
	dh->dccph_x	= 1;
	dccp_hdr_set_seq(dh, dp->dccps_gss);
	dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dp->dccps_gsr);

	dccp_hdr_reset(skb)->dccph_reset_code = code;
	inet_csk(sk)->icsk_af_ops->send_check(sk, 0, skb);

	DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
	return skb;
}
示例#6
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#7
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#8
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;
}