/* 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); /* 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); event->asoc = (struct sctp_association *)asoc; atomic_add(skb->truesize, &event->asoc->rmem_alloc); skb_set_owner_r(skb, asoc->base.sk); } /* A simple destructor to give up the reference to the association. */ static inline void sctp_ulpevent_release_owner(struct sctp_ulpevent *event) { struct sctp_association *asoc = event->asoc; struct sk_buff *skb = sctp_event2skb(event); atomic_sub(skb->truesize, &asoc->rmem_alloc); sctp_association_put(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 |= 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); 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: * * SCTP_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 SCTP_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. */ 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)); }