ulpevent.c 29.5 KB
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/* SCTP kernel implementation
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 * (C) Copyright IBM Corp. 2001, 2004
 * Copyright (c) 1999-2000 Cisco, Inc.
 * Copyright (c) 1999-2001 Motorola, Inc.
 * Copyright (c) 2001 Intel Corp.
 * Copyright (c) 2001 Nokia, Inc.
 * Copyright (c) 2001 La Monte H.P. Yarroll
 *
 * These functions manipulate an sctp event.   The struct ulpevent is used
 * to carry notifications and data to the ULP (sockets).
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 *
 * This SCTP implementation is free software;
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 * 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, or (at your option)
 * any later version.
 *
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 * This SCTP implementation is distributed in the hope that it
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 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *                 ************************
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
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 * along with GNU CC; see the file COPYING.  If not, see
 * <http://www.gnu.org/licenses/>.
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 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
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 *    lksctp developers <linux-sctp@vger.kernel.org>
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 *
 * Written or modified by:
 *    Jon Grimm             <jgrimm@us.ibm.com>
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Ardelle Fan	    <ardelle.fan@intel.com>
 *    Sridhar Samudrala     <sri@us.ibm.com>
 */

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#include <linux/slab.h>
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#include <linux/types.h>
#include <linux/skbuff.h>
#include <net/sctp/structs.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>

static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
				       struct sctp_association *asoc);
static void sctp_ulpevent_release_data(struct sctp_ulpevent *event);
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static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event);

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/* Initialize an ULP event from an given skb.  */
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static void sctp_ulpevent_init(struct sctp_ulpevent *event,
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			       __u16 msg_flags,
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			       unsigned int len)
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{
	memset(event, 0, sizeof(struct sctp_ulpevent));
	event->msg_flags = msg_flags;
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	event->rmem_len = len;
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}

/* Create a new sctp_ulpevent.  */
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static struct sctp_ulpevent *sctp_ulpevent_new(int size, __u16 msg_flags,
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					       gfp_t gfp)
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{
	struct sctp_ulpevent *event;
	struct sk_buff *skb;

	skb = alloc_skb(size, gfp);
	if (!skb)
		goto fail;

	event = sctp_skb2event(skb);
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	sctp_ulpevent_init(event, msg_flags, skb->truesize);
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	return event;

fail:
	return NULL;
}

/* Is this a MSG_NOTIFICATION?  */
int sctp_ulpevent_is_notification(const struct sctp_ulpevent *event)
{
	return MSG_NOTIFICATION == (event->msg_flags & MSG_NOTIFICATION);
}

/* Hold the association in case the msg_name needs read out of
 * the association.
 */
static inline void sctp_ulpevent_set_owner(struct sctp_ulpevent *event,
					   const struct sctp_association *asoc)
{
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	struct sctp_chunk *chunk = event->chunk;
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	struct sk_buff *skb;

	/* Cast away the const, as we are just wanting to
	 * bump the reference count.
	 */
	sctp_association_hold((struct sctp_association *)asoc);
	skb = sctp_event2skb(event);
	event->asoc = (struct sctp_association *)asoc;
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	atomic_add(event->rmem_len, &event->asoc->rmem_alloc);
	sctp_skb_set_owner_r(skb, asoc->base.sk);
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	if (chunk && chunk->head_skb && !chunk->head_skb->sk)
		chunk->head_skb->sk = asoc->base.sk;
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}

/* A simple destructor to give up the reference to the association. */
static inline void sctp_ulpevent_release_owner(struct sctp_ulpevent *event)
{
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	struct sctp_association *asoc = event->asoc;

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	atomic_sub(event->rmem_len, &asoc->rmem_alloc);
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	sctp_association_put(asoc);
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}

/* Create and initialize an SCTP_ASSOC_CHANGE event.
 *
 * 5.3.1.1 SCTP_ASSOC_CHANGE
 *
 * Communication notifications inform the ULP that an SCTP association
 * has either begun or ended. The identifier for a new association is
 * provided by this notification.
 *
 * Note: There is no field checking here.  If a field is unused it will be
 * zero'd out.
 */
struct sctp_ulpevent  *sctp_ulpevent_make_assoc_change(
	const struct sctp_association *asoc,
	__u16 flags, __u16 state, __u16 error, __u16 outbound,
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	__u16 inbound, struct sctp_chunk *chunk, gfp_t gfp)
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{
	struct sctp_ulpevent *event;
	struct sctp_assoc_change *sac;
	struct sk_buff *skb;

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	/* If the lower layer passed in the chunk, it will be
	 * an ABORT, so we need to include it in the sac_info.
	 */
	if (chunk) {
		/* Copy the chunk data to a new skb and reserve enough
		 * head room to use as notification.
		 */
		skb = skb_copy_expand(chunk->skb,
				      sizeof(struct sctp_assoc_change), 0, gfp);

		if (!skb)
			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) +
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			 ntohs(chunk->chunk_hdr->length) -
			 sizeof(sctp_chunkhdr_t));
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	} else {
		event = sctp_ulpevent_new(sizeof(struct sctp_assoc_change),
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				  MSG_NOTIFICATION, gfp);
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		if (!event)
			goto fail;

		skb = sctp_event2skb(event);
		sac = (struct sctp_assoc_change *) skb_put(skb,
					sizeof(struct sctp_assoc_change));
	}
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	/* 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.
	 */
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	sac->sac_length = skb->len;
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	/* 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;
}

/* Create and initialize an SCTP_PEER_ADDR_CHANGE event.
 *
 * Socket Extensions for SCTP - draft-01
 * 5.3.1.2 SCTP_PEER_ADDR_CHANGE
 *
 * When a destination address on a multi-homed peer encounters a change
 * an interface details event is sent.
 */
struct sctp_ulpevent *sctp_ulpevent_make_peer_addr_change(
	const struct sctp_association *asoc,
	const struct sockaddr_storage *aaddr,
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	int flags, int state, int error, gfp_t gfp)
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{
	struct sctp_ulpevent *event;
	struct sctp_paddr_change  *spc;
	struct sk_buff *skb;

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

	skb = sctp_event2skb(event);
	spc = (struct sctp_paddr_change *)
		skb_put(skb, sizeof(struct sctp_paddr_change));

	/* Sockets API Extensions for SCTP
	 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
	 *
	 * spc_type:
	 *
	 *    It should be SCTP_PEER_ADDR_CHANGE.
	 */
	spc->spc_type = SCTP_PEER_ADDR_CHANGE;

	/* Sockets API Extensions for SCTP
	 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
	 *
	 * spc_length: sizeof (__u32)
	 *
	 * This field is the total length of the notification data, including
	 * the notification header.
	 */
	spc->spc_length = sizeof(struct sctp_paddr_change);

	/* Sockets API Extensions for SCTP
	 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
	 *
	 * spc_flags: 16 bits (unsigned integer)
	 * Currently unused.
	 */
	spc->spc_flags = 0;

	/* Sockets API Extensions for SCTP
	 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
	 *
	 * spc_state:  32 bits (signed integer)
	 *
	 * This field holds one of a number of values that communicate the
	 * event that happened to the address.
	 */
	spc->spc_state = state;

	/* Sockets API Extensions for SCTP
	 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
	 *
	 * spc_error:  32 bits (signed integer)
	 *
	 * If the state was reached due to any error condition (e.g.
	 * ADDRESS_UNREACHABLE) any relevant error information is available in
	 * this field.
	 */
	spc->spc_error = error;

	/* Socket Extensions for SCTP
	 * 5.3.1.1 SCTP_ASSOC_CHANGE
	 *
	 * spc_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);
	spc->spc_assoc_id = sctp_assoc2id(asoc);

	/* Sockets API Extensions for SCTP
	 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
	 *
	 * spc_aaddr: sizeof (struct sockaddr_storage)
	 *
	 * The affected address field, holds the remote peer's address that is
	 * encountering the change of state.
	 */
	memcpy(&spc->spc_aaddr, aaddr, sizeof(struct sockaddr_storage));

	/* Map ipv4 address into v4-mapped-on-v6 address.  */
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	sctp_get_pf_specific(asoc->base.sk->sk_family)->addr_to_user(
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					sctp_sk(asoc->base.sk),
					(union sctp_addr *)&spc->spc_aaddr);

	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.
 */
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struct sctp_ulpevent *
sctp_ulpevent_make_remote_error(const struct sctp_association *asoc,
				struct sctp_chunk *chunk, __u16 flags,
				gfp_t gfp)
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{
	struct sctp_ulpevent *event;
	struct sctp_remote_error *sre;
	struct sk_buff *skb;
	sctp_errhdr_t *ch;
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	__be16 cause;
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	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.
	 */
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	skb = skb_copy_expand(chunk->skb, sizeof(*sre), 0, gfp);
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	/* 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);
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	sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
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	sre = (struct sctp_remote_error *) skb_push(skb, sizeof(*sre));
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	/* Trim the buffer to the right length.  */
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	skb_trim(skb, sizeof(*sre) + elen);
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	/* RFC6458, Section 6.1.3. SCTP_REMOTE_ERROR */
	memset(sre, 0, sizeof(*sre));
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	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;
}

/* Create and initialize a SCTP_SEND_FAILED notification.
 *
 * Socket Extensions for SCTP - draft-01
 * 5.3.1.4 SCTP_SEND_FAILED
 */
struct sctp_ulpevent *sctp_ulpevent_make_send_failed(
	const struct sctp_association *asoc, struct sctp_chunk *chunk,
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	__u16 flags, __u32 error, gfp_t gfp)
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{
	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);
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	sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
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	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
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	 * reassemble a fragmented message.
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	 */
	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 a SCTP_SHUTDOWN_EVENT notification.
 *
 * Socket Extensions for SCTP - draft-01
 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
 */
struct sctp_ulpevent *sctp_ulpevent_make_shutdown_event(
	const struct sctp_association *asoc,
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	__u16 flags, gfp_t gfp)
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{
	struct sctp_ulpevent *event;
	struct sctp_shutdown_event *sse;
	struct sk_buff *skb;

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

	skb = sctp_event2skb(event);
	sse = (struct sctp_shutdown_event *)
		skb_put(skb, sizeof(struct sctp_shutdown_event));

	/* Socket Extensions for SCTP
	 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
	 *
	 * sse_type
	 * It should be SCTP_SHUTDOWN_EVENT
	 */
	sse->sse_type = SCTP_SHUTDOWN_EVENT;

	/* Socket Extensions for SCTP
	 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
	 *
	 * sse_flags: 16 bits (unsigned integer)
	 * Currently unused.
	 */
	sse->sse_flags = 0;

	/* Socket Extensions for SCTP
	 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
	 *
	 * sse_length: sizeof (__u32)
	 * This field is the total length of the notification data, including
	 * the notification header.
	 */
	sse->sse_length = sizeof(struct sctp_shutdown_event);

	/* Socket Extensions for SCTP
	 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
	 *
	 * sse_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);
	sse->sse_assoc_id = sctp_assoc2id(asoc);

	return event;

fail:
	return NULL;
}

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/* Create and initialize a SCTP_ADAPTATION_INDICATION notification.
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 *
 * Socket Extensions for SCTP
600
 * 5.3.1.6 SCTP_ADAPTATION_INDICATION
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 */
602
struct sctp_ulpevent *sctp_ulpevent_make_adaptation_indication(
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	const struct sctp_association *asoc, gfp_t gfp)
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{
	struct sctp_ulpevent *event;
606
	struct sctp_adaptation_event *sai;
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	struct sk_buff *skb;

609
	event = sctp_ulpevent_new(sizeof(struct sctp_adaptation_event),
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				  MSG_NOTIFICATION, gfp);
	if (!event)
		goto fail;

	skb = sctp_event2skb(event);
615 616
	sai = (struct sctp_adaptation_event *)
		skb_put(skb, sizeof(struct sctp_adaptation_event));
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618
	sai->sai_type = SCTP_ADAPTATION_INDICATION;
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	sai->sai_flags = 0;
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	sai->sai_length = sizeof(struct sctp_adaptation_event);
	sai->sai_adaptation_ind = asoc->peer.adaptation_ind;
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	sctp_ulpevent_set_owner(event, asoc);
	sai->sai_assoc_id = sctp_assoc2id(asoc);

	return event;

fail:
	return NULL;
}

/* A message has been received.  Package this message as a notification
 * to pass it to the upper layers.  Go ahead and calculate the sndrcvinfo
 * even if filtered out later.
 *
 * Socket Extensions for SCTP
 * 5.2.2 SCTP Header Information Structure (SCTP_SNDRCV)
 */
struct sctp_ulpevent *sctp_ulpevent_make_rcvmsg(struct sctp_association *asoc,
						struct sctp_chunk *chunk,
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						gfp_t gfp)
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{
	struct sctp_ulpevent *event = NULL;
	struct sk_buff *skb;
	size_t padding, len;
645 646 647 648 649 650 651 652 653 654 655 656 657 658 659
	int rx_count;

	/*
	 * check to see if we need to make space for this
	 * new skb, expand the rcvbuffer if needed, or drop
	 * the frame
	 */
	if (asoc->ep->rcvbuf_policy)
		rx_count = atomic_read(&asoc->rmem_alloc);
	else
		rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);

	if (rx_count >= asoc->base.sk->sk_rcvbuf) {

		if ((asoc->base.sk->sk_userlocks & SOCK_RCVBUF_LOCK) ||
660 661
		    (!sk_rmem_schedule(asoc->base.sk, chunk->skb,
				       chunk->skb->truesize)))
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			goto fail;
	}
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	/* Clone the original skb, sharing the data.  */
	skb = skb_clone(chunk->skb, gfp);
	if (!skb)
		goto fail;

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	/* Now that all memory allocations for this chunk succeeded, we
	 * can mark it as received so the tsn_map is updated correctly.
	 */
673
	if (sctp_tsnmap_mark(&asoc->peer.tsn_map,
674 675
			     ntohl(chunk->subh.data_hdr->tsn),
			     chunk->transport))
676
		goto fail_mark;
677

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	/* First calculate the padding, so we don't inadvertently
	 * pass up the wrong length to the user.
	 *
	 * RFC 2960 - Section 3.2  Chunk Field Descriptions
	 *
	 * The total length of a chunk(including Type, Length and Value fields)
	 * MUST be a multiple of 4 bytes.  If the length of the chunk is not a
	 * multiple of 4 bytes, the sender MUST pad the chunk with all zero
	 * bytes and this padding is not included in the chunk length field.
	 * The sender should never pad with more than 3 bytes.  The receiver
	 * MUST ignore the padding bytes.
	 */
	len = ntohs(chunk->chunk_hdr->length);
	padding = WORD_ROUND(len) - len;

	/* Fixup cloned skb with just this chunks data.  */
	skb_trim(skb, chunk->chunk_end - padding - skb->data);

	/* Embed the event fields inside the cloned skb.  */
	event = sctp_skb2event(skb);

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	/* Initialize event with flags 0  and correct length
	 * Since this is a clone of the original skb, only account for
	 * the data of this chunk as other chunks will be accounted separately.
	 */
	sctp_ulpevent_init(event, 0, skb->len + sizeof(struct sk_buff));
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	/* And hold the chunk as we need it for getting the IP headers
	 * later in recvmsg
	 */
	sctp_chunk_hold(chunk);
	event->chunk = chunk;

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	sctp_ulpevent_receive_data(event, asoc);

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	event->stream = ntohs(chunk->subh.data_hdr->stream);
	event->ssn = ntohs(chunk->subh.data_hdr->ssn);
	event->ppid = chunk->subh.data_hdr->ppid;
	if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
717
		event->flags |= SCTP_UNORDERED;
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		event->cumtsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
	}
	event->tsn = ntohl(chunk->subh.data_hdr->tsn);
	event->msg_flags |= chunk->chunk_hdr->flags;

	return event;
724 725

fail_mark:
726
	sctp_chunk_put(chunk);
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	kfree_skb(skb);
fail:
	return NULL;
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}

/* Create a partial delivery related event.
 *
 * 5.3.1.7 SCTP_PARTIAL_DELIVERY_EVENT
 *
 *   When a receiver is engaged in a partial delivery of a
 *   message this notification will be used to indicate
 *   various events.
 */
struct sctp_ulpevent *sctp_ulpevent_make_pdapi(
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	const struct sctp_association *asoc, __u32 indication,
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	gfp_t gfp)
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{
	struct sctp_ulpevent *event;
	struct sctp_pdapi_event *pd;
	struct sk_buff *skb;

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

	skb = sctp_event2skb(event);
	pd = (struct sctp_pdapi_event *)
		skb_put(skb, sizeof(struct sctp_pdapi_event));

	/* pdapi_type
	 *   It should be SCTP_PARTIAL_DELIVERY_EVENT
	 *
	 * pdapi_flags: 16 bits (unsigned integer)
	 *   Currently unused.
	 */
	pd->pdapi_type = SCTP_PARTIAL_DELIVERY_EVENT;
	pd->pdapi_flags = 0;

	/* pdapi_length: 32 bits (unsigned integer)
	 *
	 * This field is the total length of the notification data, including
	 * the notification header.  It will generally be sizeof (struct
	 * sctp_pdapi_event).
	 */
	pd->pdapi_length = sizeof(struct sctp_pdapi_event);

774
	/*  pdapi_indication: 32 bits (unsigned integer)
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	 *
	 * This field holds the indication being sent to the application.
	 */
	pd->pdapi_indication = indication;

	/*  pdapi_assoc_id: sizeof (sctp_assoc_t)
	 *
	 * The association id field, holds the identifier for the association.
	 */
	sctp_ulpevent_set_owner(event, asoc);
	pd->pdapi_assoc_id = sctp_assoc2id(asoc);

	return event;
fail:
	return NULL;
}

792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808
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));

809
	ak->auth_type = SCTP_AUTHENTICATION_EVENT;
810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827
	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;
}

828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855
/*
 * 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;
}
856

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/* Return the notification type, assuming this is a notification
 * event.
 */
__u16 sctp_ulpevent_get_notification_type(const struct sctp_ulpevent *event)
{
	union sctp_notification *notification;
	struct sk_buff *skb;

865
	skb = sctp_event2skb(event);
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	notification = (union sctp_notification *) skb->data;
	return notification->sn_header.sn_type;
}

870 871 872
/* RFC6458, Section 5.3.2. SCTP Header Information Structure
 * (SCTP_SNDRCV, DEPRECATED)
 */
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void sctp_ulpevent_read_sndrcvinfo(const struct sctp_ulpevent *event,
				   struct msghdr *msghdr)
{
	struct sctp_sndrcvinfo sinfo;

	if (sctp_ulpevent_is_notification(event))
		return;

881
	memset(&sinfo, 0, sizeof(sinfo));
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	sinfo.sinfo_stream = event->stream;
	sinfo.sinfo_ssn = event->ssn;
	sinfo.sinfo_ppid = event->ppid;
	sinfo.sinfo_flags = event->flags;
	sinfo.sinfo_tsn = event->tsn;
	sinfo.sinfo_cumtsn = event->cumtsn;
	sinfo.sinfo_assoc_id = sctp_assoc2id(event->asoc);
889
	/* Context value that is set via SCTP_CONTEXT socket option. */
890
	sinfo.sinfo_context = event->asoc->default_rcv_context;
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	/* These fields are not used while receiving. */
	sinfo.sinfo_timetolive = 0;

	put_cmsg(msghdr, IPPROTO_SCTP, SCTP_SNDRCV,
895
		 sizeof(sinfo), &sinfo);
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}

898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922
/* RFC6458, Section 5.3.5 SCTP Receive Information Structure
 * (SCTP_SNDRCV)
 */
void sctp_ulpevent_read_rcvinfo(const struct sctp_ulpevent *event,
				struct msghdr *msghdr)
{
	struct sctp_rcvinfo rinfo;

	if (sctp_ulpevent_is_notification(event))
		return;

	memset(&rinfo, 0, sizeof(struct sctp_rcvinfo));
	rinfo.rcv_sid = event->stream;
	rinfo.rcv_ssn = event->ssn;
	rinfo.rcv_ppid = event->ppid;
	rinfo.rcv_flags = event->flags;
	rinfo.rcv_tsn = event->tsn;
	rinfo.rcv_cumtsn = event->cumtsn;
	rinfo.rcv_assoc_id = sctp_assoc2id(event->asoc);
	rinfo.rcv_context = event->asoc->default_rcv_context;

	put_cmsg(msghdr, IPPROTO_SCTP, SCTP_RCVINFO,
		 sizeof(rinfo), &rinfo);
}

923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960
/* RFC6458, Section 5.3.6. SCTP Next Receive Information Structure
 * (SCTP_NXTINFO)
 */
static void __sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event,
					 struct msghdr *msghdr,
					 const struct sk_buff *skb)
{
	struct sctp_nxtinfo nxtinfo;

	memset(&nxtinfo, 0, sizeof(nxtinfo));
	nxtinfo.nxt_sid = event->stream;
	nxtinfo.nxt_ppid = event->ppid;
	nxtinfo.nxt_flags = event->flags;
	if (sctp_ulpevent_is_notification(event))
		nxtinfo.nxt_flags |= SCTP_NOTIFICATION;
	nxtinfo.nxt_length = skb->len;
	nxtinfo.nxt_assoc_id = sctp_assoc2id(event->asoc);

	put_cmsg(msghdr, IPPROTO_SCTP, SCTP_NXTINFO,
		 sizeof(nxtinfo), &nxtinfo);
}

void sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event,
				struct msghdr *msghdr,
				struct sock *sk)
{
	struct sk_buff *skb;
	int err;

	skb = sctp_skb_recv_datagram(sk, MSG_PEEK, 1, &err);
	if (skb != NULL) {
		__sctp_ulpevent_read_nxtinfo(sctp_skb2event(skb),
					     msghdr, skb);
		/* Just release refcount here. */
		kfree_skb(skb);
	}
}

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/* 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);
972
	sctp_assoc_rwnd_decrease(asoc, skb_headlen(skb));
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	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
981
	 * fragments. But we allow multiple levels of fragments.
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	 */
983
	skb_walk_frags(skb, frag)
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		sctp_ulpevent_receive_data(sctp_skb2event(frag), asoc);
}

/* Do accounting for bytes just read by user and release the references to
 * the association.
989
 */
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static void sctp_ulpevent_release_data(struct sctp_ulpevent *event)
{
	struct sk_buff *skb, *frag;
993
	unsigned int	len;
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	/* Current stack structures assume that the rcv buffer is
	 * per socket.   For UDP style sockets this is not true as
	 * multiple associations may be on a single UDP-style socket.
	 * Use the local private area of the skb to track the owning
	 * association.
	 */

	skb = sctp_event2skb(event);
1003 1004 1005 1006 1007 1008
	len = skb->len;

	if (!skb->data_len)
		goto done;

	/* Don't forget the fragments. */
1009
	skb_walk_frags(skb, frag) {
1010 1011 1012 1013 1014 1015 1016 1017
		/* NOTE:  skb_shinfos are recursive. Although IP returns
		 * skb's with only 1 level of fragments, SCTP reassembly can
		 * increase the levels.
		 */
		sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
	}

done:
1018
	sctp_assoc_rwnd_increase(event->asoc, len);
1019
	sctp_chunk_put(event->chunk);
1020 1021 1022 1023 1024 1025 1026 1027
	sctp_ulpevent_release_owner(event);
}

static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event)
{
	struct sk_buff *skb, *frag;

	skb = sctp_event2skb(event);
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	if (!skb->data_len)
		goto done;

	/* Don't forget the fragments. */
1033
	skb_walk_frags(skb, frag) {
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		/* NOTE:  skb_shinfos are recursive. Although IP returns
		 * skb's with only 1 level of fragments, SCTP reassembly can
		 * increase the levels.
		 */
1038
		sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
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1039 1040 1041
	}

done:
1042
	sctp_chunk_put(event->chunk);
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	sctp_ulpevent_release_owner(event);
}

/* Free a ulpevent that has an owner.  It includes releasing the reference
 * to the owner, updating the rwnd in case of a DATA event and freeing the
 * skb.
 */
void sctp_ulpevent_free(struct sctp_ulpevent *event)
{
	if (sctp_ulpevent_is_notification(event))
		sctp_ulpevent_release_owner(event);
	else
		sctp_ulpevent_release_data(event);

	kfree_skb(sctp_event2skb(event));
}

/* Purge the skb lists holding ulpevents. */
1061
unsigned int sctp_queue_purge_ulpevents(struct sk_buff_head *list)
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{
	struct sk_buff *skb;
1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075
	unsigned int data_unread = 0;

	while ((skb = skb_dequeue(list)) != NULL) {
		struct sctp_ulpevent *event = sctp_skb2event(skb);

		if (!sctp_ulpevent_is_notification(event))
			data_unread += skb->len;

		sctp_ulpevent_free(event);
	}

	return data_unread;
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}