/* SCTP kernel reference Implementation
* (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).
* The SCTP reference implementation is free software;
* 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.
*
* The SCTP reference implementation is distributed in the hope that it
* 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
* along with GNU CC; see the file COPYING. If not, write to
* the Free Software Foundation, 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* Please send any bug reports or fixes you make to the
* email address(es):
* lksctp developers <lksctp-developers@lists.sourceforge.net>
*
* Or submit a bug report through the following website:
* http://www.sf.net/projects/lksctp
*
* 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>
*
* Any bugs reported given to us we will try to fix... any fixes shared will
* be incorporated into the next SCTP release.
*/
#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);
/* Stub skb destructor. */
static void sctp_stub_rfree(struct sk_buff *skb)
{
/* WARNING: This function is just a warning not to use the
* skb destructor. If the skb is shared, we may get the destructor
* callback on some processor that does not own the sock_lock. This
* was occuring with PACKET socket applications that were monitoring
* our skbs. We can't take the sock_lock, because we can't risk
* recursing if we do really own the sock lock. Instead, do all
* of our rwnd manipulation while we own the sock_lock outright.
*/
}
/* Initialize an ULP event from an given skb. */
SCTP_STATIC void sctp_ulpevent_init(struct sctp_ulpevent *event, int msg_flags)
{
memset(event, 0, sizeof(struct sctp_ulpevent));
event->msg_flags = msg_flags;
}
/* Create a new sctp_ulpevent. */
SCTP_STATIC struct sctp_ulpevent *sctp_ulpevent_new(int size, int msg_flags,
gfp_t gfp)
{
struct sctp_ulpevent *event;
struct sk_buff *skb;
skb = alloc_skb(size, gfp);
if (!skb)
goto fail;
event = sctp_skb2event(skb);
sctp_ulpevent_init(event, msg_flags);
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)
{
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);
skb->sk = asoc->base.sk;
event->asoc = (struct sctp_association *)asoc;
skb->destructor = sctp_stub_rfree;
}
/* A simple destructor to give up the reference to the association. */
static inline void sctp_ulpevent_release_owner(struct sctp_ulpevent *event)
{
sctp_association_put(event->asoc);
}
/* 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,
__u16 inbound, gfp_t gfp)
{
struct sctp_ulpevent *event;
struct sctp_assoc_change *sac;
struct sk_buff *skb;
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 = sizeof(struct sctp_assoc_change);
/* 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,
int flags, int state, int error, gfp_t gfp)
{
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. */
sctp_get_pf_specific(asoc->base.sk->sk_family)->addr_v4map(
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.
*/
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;
__u16 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);
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);
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,
__u16 flags, __u32 error, gfp_t gfp)
{
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);
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 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,
__u16 flags, gfp_t gfp)
{
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;
}
/* Create and initialize a SCTP_ADAPTION_INDICATION notification.
*
* Socket Extensions for SCTP
* 5.3.1.6 SCTP_ADAPTION_INDICATION
*/
struct sctp_ulpevent *sctp_ulpevent_make_adaption_indication(
const struct sctp_association *asoc, gfp_t gfp)
{
struct sctp_ulpevent *event;
struct sctp_adaption_event *sai;
struct sk_buff *skb;
event = sctp_ulpevent_new(sizeof(struct sctp_adaption_event),
MSG_NOTIFICATION, gfp);
if (!event)
goto fail;
skb = sctp_event2skb(event);
sai = (struct sctp_adaption_event *)
skb_put(skb, sizeof(struct sctp_adaption_event));
sai->sai_type = SCTP_ADAPTION_INDICATION;
sai->sai_flags = 0;
sai->sai_length = sizeof(struct sctp_adaption_event);
sai->sai_adaption_ind = asoc->peer.adaption_ind;
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,
gfp_t gfp)
{
struct sctp_ulpevent *event = NULL;
struct sk_buff *skb;
size_t padding, len;
/* Clone the original skb, sharing the data. */
skb = skb_clone(chunk->skb, gfp);
if (!skb)
goto fail;
/* 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);
/* Initialize event with flags 0. */
sctp_ulpevent_init(event, 0);
sctp_ulpevent_receive_data(event, asoc);
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) {
event->flags |= MSG_UNORDERED;
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;
event->iif = sctp_chunk_iif(chunk);
fail:
return event;
}
/* 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(
const struct sctp_association *asoc, __u32 indication,
gfp_t gfp)
{
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);
/* pdapi_indication: 32 bits (unsigned integer)
*
* 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;
}
/* 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;
skb = sctp_event2skb((struct sctp_ulpevent *)event);
notification = (union sctp_notification *) skb->data;
return notification->sn_header.sn_type;
}
/* Copy out the sndrcvinfo into a msghdr. */
void sctp_ulpevent_read_sndrcvinfo(const struct sctp_ulpevent *event,
struct msghdr *msghdr)
{
struct sctp_sndrcvinfo sinfo;
if (sctp_ulpevent_is_notification(event))
return;
/* Sockets API Extensions for SCTP
* Section 5.2.2 SCTP Header Information Structure (SCTP_SNDRCV)
*
* sinfo_stream: 16 bits (unsigned integer)
*
* For recvmsg() the SCTP stack places the message's stream number in
* this value.
*/
sinfo.sinfo_stream = event->stream;
/* sinfo_ssn: 16 bits (unsigned integer)
*
* For recvmsg() this value contains the stream sequence number that
* the remote endpoint placed in the DATA chunk. For fragmented
* messages this is the same number for all deliveries of the message
* (if more than one recvmsg() is needed to read the message).
*/
sinfo.sinfo_ssn = event->ssn;
/* sinfo_ppid: 32 bits (unsigned integer)
*
* In recvmsg() this value is
* the same information that was passed by the upper layer in the peer
* application. Please note that byte order issues are NOT accounted
* for and this information is passed opaquely by the SCTP stack from
* one end to the other.
*/
sinfo.sinfo_ppid = event->ppid;
/* sinfo_flags: 16 bits (unsigned integer)
*
* This field may contain any of the following flags and is composed of
* a bitwise OR of these values.
*
* recvmsg() flags:
*
* MSG_UNORDERED - This flag is present when the message was sent
* non-ordered.
*/
sinfo.sinfo_flags = event->flags;
/* sinfo_tsn: 32 bit (unsigned integer)
*
* For the receiving side, this field holds a TSN that was
* assigned to one of the SCTP Data Chunks.
*/
sinfo.sinfo_tsn = event->tsn;
/* sinfo_cumtsn: 32 bit (unsigned integer)
*
* This field will hold the current cumulative TSN as
* known by the underlying SCTP layer. Note this field is
* ignored when sending and only valid for a receive
* operation when sinfo_flags are set to MSG_UNORDERED.
*/
sinfo.sinfo_cumtsn = event->cumtsn;
/* sinfo_assoc_id: sizeof (sctp_assoc_t)
*
* The association handle field, sinfo_assoc_id, holds the identifier
* for the association announced in the COMMUNICATION_UP notification.
* All notifications for a given association have the same identifier.
* Ignored for one-to-one style sockets.
*/
sinfo.sinfo_assoc_id = sctp_assoc2id(event->asoc);
/* These fields are not used while receiving. */
sinfo.sinfo_context = 0;
sinfo.sinfo_timetolive = 0;
put_cmsg(msghdr, IPPROTO_SCTP, SCTP_SNDRCV,
sizeof(struct sctp_sndrcvinfo), (void *)&sinfo);
}
/* 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.
*/
for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
sctp_ulpevent_receive_data(sctp_skb2event(frag), asoc);
}
}
/* Do accounting for bytes just read by user and release the references to
* the association.
*/
static void sctp_ulpevent_release_data(struct sctp_ulpevent *event)
{
struct sk_buff *skb, *frag;
/* 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);
sctp_assoc_rwnd_increase(event->asoc, skb_headlen(skb));
if (!skb->data_len)
goto done;
/* Don't forget the fragments. */
for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
/* 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_data(sctp_skb2event(frag));
}
done:
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.
* See comments in sctp_stub_rfree().
*/
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. */
void sctp_queue_purge_ulpevents(struct sk_buff_head *list)
{
struct sk_buff *skb;
while ((skb = skb_dequeue(list)) != NULL)
sctp_ulpevent_free(sctp_skb2event(skb));
}
