struct sctp_ulpevent *sctp_ulpevent_make_stream_reset_event(
	const struct sctp_association *asoc, __u16 flags, __u16 stream_num,
	__u16 *stream_list, gfp_t gfp)
{
	struct sctp_stream_reset_event *sreset;
	struct sctp_ulpevent *event;
	struct sk_buff *skb;
	int length, i;

	length = sizeof(struct sctp_stream_reset_event) + 2 * stream_num;
	event = sctp_ulpevent_new(length, MSG_NOTIFICATION, gfp);
	if (!event)
		return NULL;

	skb = sctp_event2skb(event);
	sreset = (struct sctp_stream_reset_event *)skb_put(skb, length);

	sreset->strreset_type = SCTP_STREAM_RESET_EVENT;
	sreset->strreset_flags = flags;
	sreset->strreset_length = length;
	sctp_ulpevent_set_owner(event, asoc);
	sreset->strreset_assoc_id = sctp_assoc2id(asoc);

	for (i = 0; i < stream_num; i++)
		sreset->strreset_stream_list[i] = ntohs(stream_list[i]);

	return event;
}

struct sctp_ulpevent *sctp_ulpevent_make_authkey(
	const struct sctp_association *asoc, __u16 key_id,
	__u32 indication, gfp_t gfp)
{
	struct sctp_ulpevent *event;
	struct sctp_authkey_event *ak;
	struct sk_buff *skb;

	event = sctp_ulpevent_new(sizeof(struct sctp_authkey_event),
				  MSG_NOTIFICATION, gfp);
	if (!event)
		goto fail;

	skb = sctp_event2skb(event);
	ak = (struct sctp_authkey_event *)
		skb_put(skb, sizeof(struct sctp_authkey_event));

	ak->auth_type = SCTP_AUTHENTICATION_INDICATION;
	ak->auth_flags = 0;
	ak->auth_length = sizeof(struct sctp_authkey_event);

	ak->auth_keynumber = key_id;
	ak->auth_altkeynumber = 0;
	ak->auth_indication = indication;

	/*
	 * The association id field, holds the identifier for the association.
	 */
	sctp_ulpevent_set_owner(event, asoc);
	ak->auth_assoc_id = sctp_assoc2id(asoc);

	return event;
fail:
	return NULL;
}

/* Create and initialize an SCTP_REMOTE_ERROR notification.
 *
 * Note: This assumes that the chunk->skb->data already points to the
 * operation error payload.
 *
 * Socket Extensions for SCTP - draft-01
 * 5.3.1.3 SCTP_REMOTE_ERROR
 *
 * A remote peer may send an Operational Error message to its peer.
 * This message indicates a variety of error conditions on an
 * association. The entire error TLV as it appears on the wire is
 * included in a SCTP_REMOTE_ERROR event.  Please refer to the SCTP
 * specification [SCTP] and any extensions for a list of possible
 * error formats.
 */
struct sctp_ulpevent *
sctp_ulpevent_make_remote_error(const struct sctp_association *asoc,
				struct sctp_chunk *chunk, __u16 flags,
				gfp_t gfp)
{
	struct sctp_ulpevent *event;
	struct sctp_remote_error *sre;
	struct sk_buff *skb;
	sctp_errhdr_t *ch;
	__be16 cause;
	int elen;

	ch = (sctp_errhdr_t *)(chunk->skb->data);
	cause = ch->cause;
	elen = SCTP_PAD4(ntohs(ch->length)) - sizeof(sctp_errhdr_t);

	/* Pull off the ERROR header.  */
	skb_pull(chunk->skb, sizeof(sctp_errhdr_t));

	/* Copy the skb to a new skb with room for us to prepend
	 * notification with.
	 */
	skb = skb_copy_expand(chunk->skb, sizeof(*sre), 0, gfp);

	/* Pull off the rest of the cause TLV from the chunk.  */
	skb_pull(chunk->skb, elen);
	if (!skb)
		goto fail;

	/* Embed the event fields inside the cloned skb.  */
	event = sctp_skb2event(skb);
	sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);

	sre = (struct sctp_remote_error *) skb_push(skb, sizeof(*sre));

	/* Trim the buffer to the right length.  */
	skb_trim(skb, sizeof(*sre) + elen);

	/* RFC6458, Section 6.1.3. SCTP_REMOTE_ERROR */
	memset(sre, 0, sizeof(*sre));
	sre->sre_type = SCTP_REMOTE_ERROR;
	sre->sre_flags = 0;
	sre->sre_length = skb->len;
	sre->sre_error = cause;
	sctp_ulpevent_set_owner(event, asoc);
	sre->sre_assoc_id = sctp_assoc2id(asoc);

	return event;
fail:
	return NULL;
}

/* Do accounting for bytes received and hold a reference to the association
 * for each skb.
 */
static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
				       struct sctp_association *asoc)
{
	struct sk_buff *skb, *frag;

	skb = sctp_event2skb(event);
	/* Set the owner and charge rwnd for bytes received.  */
	sctp_ulpevent_set_owner(event, asoc);
	sctp_assoc_rwnd_decrease(asoc, skb_headlen(skb));

	if (!skb->data_len)
		return;

	/* Note:  Not clearing the entire event struct as this is just a
	 * fragment of the real event.  However, we still need to do rwnd
	 * accounting.
	 * In general, the skb passed from IP can have only 1 level of
	 * fragments. But we allow multiple levels of fragments.
	 */
	skb_walk_frags(skb, frag)
		sctp_ulpevent_receive_data(sctp_skb2event(frag), asoc);
}

/*
 * Socket Extensions for SCTP
 * 6.3.10. SCTP_SENDER_DRY_EVENT
 */
struct sctp_ulpevent *sctp_ulpevent_make_sender_dry_event(
	const struct sctp_association *asoc, gfp_t gfp)
{
	struct sctp_ulpevent *event;
	struct sctp_sender_dry_event *sdry;
	struct sk_buff *skb;

	event = sctp_ulpevent_new(sizeof(struct sctp_sender_dry_event),
				  MSG_NOTIFICATION, gfp);
	if (!event)
		return NULL;

	skb = sctp_event2skb(event);
	sdry = (struct sctp_sender_dry_event *)
		skb_put(skb, sizeof(struct sctp_sender_dry_event));

	sdry->sender_dry_type = SCTP_SENDER_DRY_EVENT;
	sdry->sender_dry_flags = 0;
	sdry->sender_dry_length = sizeof(struct sctp_sender_dry_event);
	sctp_ulpevent_set_owner(event, asoc);
	sdry->sender_dry_assoc_id = sctp_assoc2id(asoc);

	return event;
}

//.........这里部分代码省略.........
{
	struct sctp_ulpevent *event;
	struct sctp_send_failed *ssf;
	struct sk_buff *skb;

	/* Pull off any padding. */
	int len = ntohs(chunk->chunk_hdr->length);

	/* Make skb with more room so we can prepend notification.  */
	skb = skb_copy_expand(chunk->skb,
			      sizeof(struct sctp_send_failed), /* headroom */
			      0,                               /* tailroom */
			      gfp);
	if (!skb)
		goto fail;

	/* Pull off the common chunk header and DATA header.  */
	skb_pull(skb, sizeof(struct sctp_data_chunk));
	len -= sizeof(struct sctp_data_chunk);

	/* Embed the event fields inside the cloned skb.  */
	event = sctp_skb2event(skb);
	sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);

	ssf = (struct sctp_send_failed *)
		skb_push(skb, sizeof(struct sctp_send_failed));

	/* Socket Extensions for SCTP
	 * 5.3.1.4 SCTP_SEND_FAILED
	 *
	 * ssf_type:
	 * It should be SCTP_SEND_FAILED.
	 */
	ssf->ssf_type = SCTP_SEND_FAILED;

	/* Socket Extensions for SCTP
	 * 5.3.1.4 SCTP_SEND_FAILED
	 *
	 * ssf_flags: 16 bits (unsigned integer)
	 * The flag value will take one of the following values
	 *
	 * SCTP_DATA_UNSENT - Indicates that the data was never put on
	 *                    the wire.
	 *
	 * SCTP_DATA_SENT   - Indicates that the data was put on the wire.
	 *                    Note that this does not necessarily mean that the
	 *                    data was (or was not) successfully delivered.
	 */
	ssf->ssf_flags = flags;

	/* Socket Extensions for SCTP
	 * 5.3.1.4 SCTP_SEND_FAILED
	 *
	 * ssf_length: sizeof (__u32)
	 * This field is the total length of the notification data, including
	 * the notification header.
	 */
	ssf->ssf_length = sizeof(struct sctp_send_failed) + len;
	skb_trim(skb, ssf->ssf_length);

	/* Socket Extensions for SCTP
	 * 5.3.1.4 SCTP_SEND_FAILED
	 *
	 * ssf_error: 16 bits (unsigned integer)
	 * This value represents the reason why the send failed, and if set,
	 * will be a SCTP protocol error code as defined in [SCTP] section
	 * 3.3.10.
	 */
	ssf->ssf_error = error;

	/* Socket Extensions for SCTP
	 * 5.3.1.4 SCTP_SEND_FAILED
	 *
	 * ssf_info: sizeof (struct sctp_sndrcvinfo)
	 * The original send information associated with the undelivered
	 * message.
	 */
	memcpy(&ssf->ssf_info, &chunk->sinfo, sizeof(struct sctp_sndrcvinfo));

	/* Per TSVWG discussion with Randy. Allow the application to
	 * ressemble a fragmented message.
	 */
	ssf->ssf_info.sinfo_flags = chunk->chunk_hdr->flags;

	/* Socket Extensions for SCTP
	 * 5.3.1.4 SCTP_SEND_FAILED
	 *
	 * ssf_assoc_id: sizeof (sctp_assoc_t)
	 * The association id field, sf_assoc_id, holds the identifier for the
	 * association.  All notifications for a given association have the
	 * same association identifier.  For TCP style socket, this field is
	 * ignored.
	 */
	sctp_ulpevent_set_owner(event, asoc);
	ssf->ssf_assoc_id = sctp_assoc2id(asoc);
	return event;

fail:
	return NULL;
}

/* Create and initialize an SCTP_REMOTE_ERROR notification.
 *
 * Note: This assumes that the chunk->skb->data already points to the
 * operation error payload.
 *
 * Socket Extensions for SCTP - draft-01
 * 5.3.1.3 SCTP_REMOTE_ERROR
 *
 * A remote peer may send an Operational Error message to its peer.
 * This message indicates a variety of error conditions on an
 * association. The entire error TLV as it appears on the wire is
 * included in a SCTP_REMOTE_ERROR event.  Please refer to the SCTP
 * specification [SCTP] and any extensions for a list of possible
 * error formats.
 */
struct sctp_ulpevent *sctp_ulpevent_make_remote_error(
	const struct sctp_association *asoc, struct sctp_chunk *chunk,
	__u16 flags, gfp_t gfp)
{
	struct sctp_ulpevent *event;
	struct sctp_remote_error *sre;
	struct sk_buff *skb;
	sctp_errhdr_t *ch;
	__be16 cause;
	int elen;

	ch = (sctp_errhdr_t *)(chunk->skb->data);
	cause = ch->cause;
	elen = WORD_ROUND(ntohs(ch->length)) - sizeof(sctp_errhdr_t);

	/* Pull off the ERROR header.  */
	skb_pull(chunk->skb, sizeof(sctp_errhdr_t));

	/* Copy the skb to a new skb with room for us to prepend
	 * notification with.
	 */
	skb = skb_copy_expand(chunk->skb, sizeof(struct sctp_remote_error),
			      0, gfp);

	/* Pull off the rest of the cause TLV from the chunk.  */
	skb_pull(chunk->skb, elen);
	if (!skb)
		goto fail;

	/* Embed the event fields inside the cloned skb.  */
	event = sctp_skb2event(skb);
	sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);

	sre = (struct sctp_remote_error *)
		skb_push(skb, sizeof(struct sctp_remote_error));

	/* Trim the buffer to the right length.  */
	skb_trim(skb, sizeof(struct sctp_remote_error) + elen);

	/* Socket Extensions for SCTP
	 * 5.3.1.3 SCTP_REMOTE_ERROR
	 *
	 * sre_type:
	 *   It should be SCTP_REMOTE_ERROR.
	 */
	sre->sre_type = SCTP_REMOTE_ERROR;

	/*
	 * Socket Extensions for SCTP
	 * 5.3.1.3 SCTP_REMOTE_ERROR
	 *
	 * sre_flags: 16 bits (unsigned integer)
	 *   Currently unused.
	 */
	sre->sre_flags = 0;

	/* Socket Extensions for SCTP
	 * 5.3.1.3 SCTP_REMOTE_ERROR
	 *
	 * sre_length: sizeof (__u32)
	 *
	 * This field is the total length of the notification data,
	 * including the notification header.
	 */
	sre->sre_length = skb->len;

	/* Socket Extensions for SCTP
	 * 5.3.1.3 SCTP_REMOTE_ERROR
	 *
	 * sre_error: 16 bits (unsigned integer)
	 * This value represents one of the Operational Error causes defined in
	 * the SCTP specification, in network byte order.
	 */
	sre->sre_error = cause;

	/* Socket Extensions for SCTP
	 * 5.3.1.3 SCTP_REMOTE_ERROR
	 *
	 * sre_assoc_id: sizeof (sctp_assoc_t)
	 *
	 * The association id field, holds the identifier for the association.
	 * All notifications for a given association have the same association
	 * identifier.  For TCP style socket, this field is ignored.
	 */
	sctp_ulpevent_set_owner(event, asoc);
//.........这里部分代码省略.........

//.........这里部分代码省略.........
			goto fail;

		/* Embed the event fields inside the cloned skb.  */
		event = sctp_skb2event(skb);
		sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);

		/* Include the notification structure */
		sac = (struct sctp_assoc_change *)
			skb_push(skb, sizeof(struct sctp_assoc_change));

		/* Trim the buffer to the right length.  */
		skb_trim(skb, sizeof(struct sctp_assoc_change) +
			 ntohs(chunk->chunk_hdr->length) -
			 sizeof(sctp_chunkhdr_t));
	} else {
		event = sctp_ulpevent_new(sizeof(struct sctp_assoc_change),
				  MSG_NOTIFICATION, gfp);
		if (!event)
			goto fail;

		skb = sctp_event2skb(event);
		sac = (struct sctp_assoc_change *) skb_put(skb,
					sizeof(struct sctp_assoc_change));
	}

	/* Socket Extensions for SCTP
	 * 5.3.1.1 SCTP_ASSOC_CHANGE
	 *
	 * sac_type:
	 * It should be SCTP_ASSOC_CHANGE.
	 */
	sac->sac_type = SCTP_ASSOC_CHANGE;

	/* Socket Extensions for SCTP
	 * 5.3.1.1 SCTP_ASSOC_CHANGE
	 *
	 * sac_state: 32 bits (signed integer)
	 * This field holds one of a number of values that communicate the
	 * event that happened to the association.
	 */
	sac->sac_state = state;

	/* Socket Extensions for SCTP
	 * 5.3.1.1 SCTP_ASSOC_CHANGE
	 *
	 * sac_flags: 16 bits (unsigned integer)
	 * Currently unused.
	 */
	sac->sac_flags = 0;

	/* Socket Extensions for SCTP
	 * 5.3.1.1 SCTP_ASSOC_CHANGE
	 *
	 * sac_length: sizeof (__u32)
	 * This field is the total length of the notification data, including
	 * the notification header.
	 */
	sac->sac_length = skb->len;

	/* Socket Extensions for SCTP
	 * 5.3.1.1 SCTP_ASSOC_CHANGE
	 *
	 * sac_error:  32 bits (signed integer)
	 *
	 * If the state was reached due to a error condition (e.g.
	 * COMMUNICATION_LOST) any relevant error information is available in
	 * this field. This corresponds to the protocol error codes defined in
	 * [SCTP].
	 */
	sac->sac_error = error;

	/* Socket Extensions for SCTP
	 * 5.3.1.1 SCTP_ASSOC_CHANGE
	 *
	 * sac_outbound_streams:  16 bits (unsigned integer)
	 * sac_inbound_streams:  16 bits (unsigned integer)
	 *
	 * The maximum number of streams allowed in each direction are
	 * available in sac_outbound_streams and sac_inbound streams.
	 */
	sac->sac_outbound_streams = outbound;
	sac->sac_inbound_streams = inbound;

	/* Socket Extensions for SCTP
	 * 5.3.1.1 SCTP_ASSOC_CHANGE
	 *
	 * sac_assoc_id: sizeof (sctp_assoc_t)
	 *
	 * The association id field, holds the identifier for the association.
	 * All notifications for a given association have the same association
	 * identifier.  For TCP style socket, this field is ignored.
	 */
	sctp_ulpevent_set_owner(event, asoc);
	sac->sac_assoc_id = sctp_assoc2id(asoc);

	return event;

fail:
	return NULL;
}