/* 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;
unsigned int len;
/* 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);
len = skb->len;
if (!skb->data_len)
goto done;
/* Don't forget the fragments. */
skb_walk_frags(skb, frag) {
/* 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));
}
/* 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;
}
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);
}
}
/* Purge the skb lists holding ulpevents. */
unsigned int sctp_queue_purge_ulpevents(struct sk_buff_head *list)
{
struct sk_buff *skb;
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;
}
static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event)
{
struct sk_buff *skb, *frag;
skb = sctp_event2skb(event);
if (!skb->data_len)
goto done;
/* Don't forget the fragments. */
skb_walk_frags(skb, frag) {
/* 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));
}
/* 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, skb->truesize);
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);
}
/* 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;
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) ||
(!sk_rmem_schedule(asoc->base.sk, chunk->skb->truesize)))
goto fail;
}
/* Clone the original skb, sharing the data. */
skb = skb_clone(chunk->skb, gfp);
if (!skb)
goto fail;
/* Now that all memory allocations for this chunk succeeded, we
* can mark it as received so the tsn_map is updated correctly.
*/
if (sctp_tsnmap_mark(&asoc->peer.tsn_map,
ntohl(chunk->subh.data_hdr->tsn)))
goto fail_mark;
/* 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 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));
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 |= SCTP_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);
return event;
fail_mark:
kfree_skb(skb);
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, 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);
sre->sre_assoc_id = sctp_assoc2id(asoc);
return event;
fail:
return NULL;
}
/* 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, struct sctp_chunk *chunk, gfp_t gfp)
{
struct sctp_ulpevent *event;
struct sctp_assoc_change *sac;
struct sk_buff *skb;
/* 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) +
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;
}
/* 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));
}
