diff options
Diffstat (limited to 'net/sctp/ulpevent.c')
| -rw-r--r-- | net/sctp/ulpevent.c | 942 |
1 files changed, 942 insertions, 0 deletions
diff --git a/net/sctp/ulpevent.c b/net/sctp/ulpevent.c new file mode 100644 index 0000000..17d0ff5 --- /dev/null +++ b/net/sctp/ulpevent.c @@ -0,0 +1,942 @@ +/* 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, + int 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, int 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, int 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, int 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, int 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, int 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, int 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, + int 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, int 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)); +} |