diff options
Diffstat (limited to 'net/sctp/ulpevent.c')
| -rw-r--r-- | net/sctp/ulpevent.c | 1190 |
1 files changed, 1190 insertions, 0 deletions
diff --git a/net/sctp/ulpevent.c b/net/sctp/ulpevent.c new file mode 100644 index 000000000..8920ca92a --- /dev/null +++ b/net/sctp/ulpevent.c @@ -0,0 +1,1190 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* SCTP kernel 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). + * + * Please send any bug reports or fixes you make to the + * email address(es): + * lksctp developers <linux-sctp@vger.kernel.org> + * + * 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> + */ + +#include <linux/slab.h> +#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); +static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event); + + +/* Initialize an ULP event from an given skb. */ +static void sctp_ulpevent_init(struct sctp_ulpevent *event, + __u16 msg_flags, + unsigned int len) +{ + memset(event, 0, sizeof(struct sctp_ulpevent)); + event->msg_flags = msg_flags; + event->rmem_len = len; +} + +/* Create a new sctp_ulpevent. */ +static struct sctp_ulpevent *sctp_ulpevent_new(int size, __u16 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; +} + +/* 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 sctp_chunk *chunk = event->chunk; + 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(event->rmem_len, &event->asoc->rmem_alloc); + sctp_skb_set_owner_r(skb, asoc->base.sk); + if (chunk && chunk->head_skb && !chunk->head_skb->sk) + chunk->head_skb->sk = 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; + + atomic_sub(event->rmem_len, &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, 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 = 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(struct sctp_chunkhdr)); + } else { + event = sctp_ulpevent_new(sizeof(struct sctp_assoc_change), + MSG_NOTIFICATION, gfp); + if (!event) + goto fail; + + skb = sctp_event2skb(event); + sac = 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; +} + +/* 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. + */ +static 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 = 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_to_user( + sctp_sk(asoc->base.sk), + (union sctp_addr *)&spc->spc_aaddr); + + return event; + +fail: + return NULL; +} + +void sctp_ulpevent_notify_peer_addr_change(struct sctp_transport *transport, + int state, int error) +{ + struct sctp_association *asoc = transport->asoc; + struct sockaddr_storage addr; + struct sctp_ulpevent *event; + + if (asoc->state < SCTP_STATE_ESTABLISHED) + return; + + memset(&addr, 0, sizeof(struct sockaddr_storage)); + memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len); + + event = sctp_ulpevent_make_peer_addr_change(asoc, &addr, 0, state, + error, GFP_ATOMIC); + if (event) + asoc->stream.si->enqueue_event(&asoc->ulpq, event); +} + +/* 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_remote_error *sre; + struct sctp_ulpevent *event; + struct sctp_errhdr *ch; + struct sk_buff *skb; + __be16 cause; + int elen; + + ch = (struct sctp_errhdr *)(chunk->skb->data); + cause = ch->cause; + elen = SCTP_PAD4(ntohs(ch->length)) - sizeof(*ch); + + /* Pull off the ERROR header. */ + skb_pull(chunk->skb, sizeof(*ch)); + + /* 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 = 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; +} + +/* 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, sctp_datachk_len(&asoc->stream)); + len -= sctp_datachk_len(&asoc->stream); + + /* Embed the event fields inside the cloned skb. */ + event = sctp_skb2event(skb); + sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize); + + ssf = 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 + * reassemble 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; +} + +struct sctp_ulpevent *sctp_ulpevent_make_send_failed_event( + const struct sctp_association *asoc, struct sctp_chunk *chunk, + __u16 flags, __u32 error, gfp_t gfp) +{ + struct sctp_send_failed_event *ssf; + struct sctp_ulpevent *event; + struct sk_buff *skb; + int len; + + skb = skb_copy_expand(chunk->skb, sizeof(*ssf), 0, gfp); + if (!skb) + return NULL; + + len = ntohs(chunk->chunk_hdr->length); + len -= sctp_datachk_len(&asoc->stream); + + skb_pull(skb, sctp_datachk_len(&asoc->stream)); + event = sctp_skb2event(skb); + sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize); + + ssf = skb_push(skb, sizeof(*ssf)); + ssf->ssf_type = SCTP_SEND_FAILED_EVENT; + ssf->ssf_flags = flags; + ssf->ssf_length = sizeof(*ssf) + len; + skb_trim(skb, ssf->ssf_length); + ssf->ssf_error = error; + + ssf->ssfe_info.snd_sid = chunk->sinfo.sinfo_stream; + ssf->ssfe_info.snd_ppid = chunk->sinfo.sinfo_ppid; + ssf->ssfe_info.snd_context = chunk->sinfo.sinfo_context; + ssf->ssfe_info.snd_assoc_id = chunk->sinfo.sinfo_assoc_id; + ssf->ssfe_info.snd_flags = chunk->chunk_hdr->flags; + + sctp_ulpevent_set_owner(event, asoc); + ssf->ssf_assoc_id = sctp_assoc2id(asoc); + + return event; +} + +/* 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 = 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_ADAPTATION_INDICATION notification. + * + * Socket Extensions for SCTP + * 5.3.1.6 SCTP_ADAPTATION_INDICATION + */ +struct sctp_ulpevent *sctp_ulpevent_make_adaptation_indication( + const struct sctp_association *asoc, gfp_t gfp) +{ + struct sctp_ulpevent *event; + struct sctp_adaptation_event *sai; + struct sk_buff *skb; + + event = sctp_ulpevent_new(sizeof(struct sctp_adaptation_event), + MSG_NOTIFICATION, gfp); + if (!event) + goto fail; + + skb = sctp_event2skb(event); + sai = skb_put(skb, sizeof(struct sctp_adaptation_event)); + + sai->sai_type = SCTP_ADAPTATION_INDICATION; + sai->sai_flags = 0; + sai->sai_length = sizeof(struct sctp_adaptation_event); + sai->sai_adaptation_ind = asoc->peer.adaptation_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 = chunk->skb; + struct sock *sk = asoc->base.sk; + size_t padding, datalen; + 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(&sk->sk_rmem_alloc); + + datalen = ntohs(chunk->chunk_hdr->length); + + if (rx_count >= sk->sk_rcvbuf || !sk_rmem_schedule(sk, skb, datalen)) + 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), + chunk->transport)) + 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. + */ + padding = SCTP_PAD4(datalen) - datalen; + + /* 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)); + + /* And hold the chunk as we need it for getting the IP headers + * later in recvmsg + */ + sctp_chunk_hold(chunk); + event->chunk = chunk; + + sctp_ulpevent_receive_data(event, asoc); + + event->stream = ntohs(chunk->subh.data_hdr->stream); + 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; + + return event; + +fail_mark: + kfree_skb(skb); +fail: + return NULL; +} + +/* 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, __u32 sid, __u32 seq, + __u32 flags, 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 = 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 = flags; + pd->pdapi_stream = sid; + pd->pdapi_seq = seq; + + /* 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; +} + +struct sctp_ulpevent *sctp_ulpevent_make_authkey( + const struct sctp_association *asoc, __u16 key_id, + __u32 indication, gfp_t gfp) +{ + struct sctp_ulpevent *event; + struct sctp_authkey_event *ak; + struct sk_buff *skb; + + event = sctp_ulpevent_new(sizeof(struct sctp_authkey_event), + MSG_NOTIFICATION, gfp); + if (!event) + goto fail; + + skb = sctp_event2skb(event); + ak = skb_put(skb, sizeof(struct sctp_authkey_event)); + + ak->auth_type = SCTP_AUTHENTICATION_EVENT; + ak->auth_flags = 0; + ak->auth_length = sizeof(struct sctp_authkey_event); + + ak->auth_keynumber = key_id; + ak->auth_altkeynumber = 0; + ak->auth_indication = indication; + + /* + * The association id field, holds the identifier for the association. + */ + sctp_ulpevent_set_owner(event, asoc); + ak->auth_assoc_id = sctp_assoc2id(asoc); + + return event; +fail: + return NULL; +} + +/* + * Socket Extensions for SCTP + * 6.3.10. SCTP_SENDER_DRY_EVENT + */ +struct sctp_ulpevent *sctp_ulpevent_make_sender_dry_event( + const struct sctp_association *asoc, gfp_t gfp) +{ + struct sctp_ulpevent *event; + struct sctp_sender_dry_event *sdry; + struct sk_buff *skb; + + event = sctp_ulpevent_new(sizeof(struct sctp_sender_dry_event), + MSG_NOTIFICATION, gfp); + if (!event) + return NULL; + + skb = sctp_event2skb(event); + sdry = skb_put(skb, sizeof(struct sctp_sender_dry_event)); + + sdry->sender_dry_type = SCTP_SENDER_DRY_EVENT; + sdry->sender_dry_flags = 0; + sdry->sender_dry_length = sizeof(struct sctp_sender_dry_event); + sctp_ulpevent_set_owner(event, asoc); + sdry->sender_dry_assoc_id = sctp_assoc2id(asoc); + + return event; +} + +struct sctp_ulpevent *sctp_ulpevent_make_stream_reset_event( + const struct sctp_association *asoc, __u16 flags, __u16 stream_num, + __be16 *stream_list, gfp_t gfp) +{ + struct sctp_stream_reset_event *sreset; + struct sctp_ulpevent *event; + struct sk_buff *skb; + int length, i; + + length = sizeof(struct sctp_stream_reset_event) + 2 * stream_num; + event = sctp_ulpevent_new(length, MSG_NOTIFICATION, gfp); + if (!event) + return NULL; + + skb = sctp_event2skb(event); + sreset = skb_put(skb, length); + + sreset->strreset_type = SCTP_STREAM_RESET_EVENT; + sreset->strreset_flags = flags; + sreset->strreset_length = length; + sctp_ulpevent_set_owner(event, asoc); + sreset->strreset_assoc_id = sctp_assoc2id(asoc); + + for (i = 0; i < stream_num; i++) + sreset->strreset_stream_list[i] = ntohs(stream_list[i]); + + return event; +} + +struct sctp_ulpevent *sctp_ulpevent_make_assoc_reset_event( + const struct sctp_association *asoc, __u16 flags, __u32 local_tsn, + __u32 remote_tsn, gfp_t gfp) +{ + struct sctp_assoc_reset_event *areset; + struct sctp_ulpevent *event; + struct sk_buff *skb; + + event = sctp_ulpevent_new(sizeof(struct sctp_assoc_reset_event), + MSG_NOTIFICATION, gfp); + if (!event) + return NULL; + + skb = sctp_event2skb(event); + areset = skb_put(skb, sizeof(struct sctp_assoc_reset_event)); + + areset->assocreset_type = SCTP_ASSOC_RESET_EVENT; + areset->assocreset_flags = flags; + areset->assocreset_length = sizeof(struct sctp_assoc_reset_event); + sctp_ulpevent_set_owner(event, asoc); + areset->assocreset_assoc_id = sctp_assoc2id(asoc); + areset->assocreset_local_tsn = local_tsn; + areset->assocreset_remote_tsn = remote_tsn; + + return event; +} + +struct sctp_ulpevent *sctp_ulpevent_make_stream_change_event( + const struct sctp_association *asoc, __u16 flags, + __u32 strchange_instrms, __u32 strchange_outstrms, gfp_t gfp) +{ + struct sctp_stream_change_event *schange; + struct sctp_ulpevent *event; + struct sk_buff *skb; + + event = sctp_ulpevent_new(sizeof(struct sctp_stream_change_event), + MSG_NOTIFICATION, gfp); + if (!event) + return NULL; + + skb = sctp_event2skb(event); + schange = skb_put(skb, sizeof(struct sctp_stream_change_event)); + + schange->strchange_type = SCTP_STREAM_CHANGE_EVENT; + schange->strchange_flags = flags; + schange->strchange_length = sizeof(struct sctp_stream_change_event); + sctp_ulpevent_set_owner(event, asoc); + schange->strchange_assoc_id = sctp_assoc2id(asoc); + schange->strchange_instrms = strchange_instrms; + schange->strchange_outstrms = strchange_outstrms; + + return event; +} + +/* 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(event); + notification = (union sctp_notification *) skb->data; + return notification->sn_header.sn_type; +} + +/* RFC6458, Section 5.3.2. SCTP Header Information Structure + * (SCTP_SNDRCV, DEPRECATED) + */ +void sctp_ulpevent_read_sndrcvinfo(const struct sctp_ulpevent *event, + struct msghdr *msghdr) +{ + struct sctp_sndrcvinfo sinfo; + + if (sctp_ulpevent_is_notification(event)) + return; + + memset(&sinfo, 0, sizeof(sinfo)); + sinfo.sinfo_stream = event->stream; + sinfo.sinfo_ssn = event->ssn; + sinfo.sinfo_ppid = event->ppid; + sinfo.sinfo_flags = event->flags; + sinfo.sinfo_tsn = event->tsn; + sinfo.sinfo_cumtsn = event->cumtsn; + sinfo.sinfo_assoc_id = sctp_assoc2id(event->asoc); + /* Context value that is set via SCTP_CONTEXT socket option. */ + sinfo.sinfo_context = event->asoc->default_rcv_context; + /* These fields are not used while receiving. */ + sinfo.sinfo_timetolive = 0; + + put_cmsg(msghdr, IPPROTO_SCTP, SCTP_SNDRCV, + sizeof(sinfo), &sinfo); +} + +/* RFC6458, Section 5.3.5 SCTP Receive Information Structure + * (SCTP_SNDRCV) + */ +void sctp_ulpevent_read_rcvinfo(const struct sctp_ulpevent *event, + struct msghdr *msghdr) +{ + struct sctp_rcvinfo rinfo; + + if (sctp_ulpevent_is_notification(event)) + return; + + memset(&rinfo, 0, sizeof(struct sctp_rcvinfo)); + rinfo.rcv_sid = event->stream; + rinfo.rcv_ssn = event->ssn; + rinfo.rcv_ppid = event->ppid; + rinfo.rcv_flags = event->flags; + rinfo.rcv_tsn = event->tsn; + rinfo.rcv_cumtsn = event->cumtsn; + rinfo.rcv_assoc_id = sctp_assoc2id(event->asoc); + rinfo.rcv_context = event->asoc->default_rcv_context; + + put_cmsg(msghdr, IPPROTO_SCTP, SCTP_RCVINFO, + sizeof(rinfo), &rinfo); +} + +/* RFC6458, Section 5.3.6. SCTP Next Receive Information Structure + * (SCTP_NXTINFO) + */ +static void __sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event, + struct msghdr *msghdr, + const struct sk_buff *skb) +{ + struct sctp_nxtinfo nxtinfo; + + memset(&nxtinfo, 0, sizeof(nxtinfo)); + nxtinfo.nxt_sid = event->stream; + nxtinfo.nxt_ppid = event->ppid; + nxtinfo.nxt_flags = event->flags; + if (sctp_ulpevent_is_notification(event)) + nxtinfo.nxt_flags |= SCTP_NOTIFICATION; + nxtinfo.nxt_length = skb->len; + nxtinfo.nxt_assoc_id = sctp_assoc2id(event->asoc); + + put_cmsg(msghdr, IPPROTO_SCTP, SCTP_NXTINFO, + sizeof(nxtinfo), &nxtinfo); +} + +void sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event, + struct msghdr *msghdr, + struct sock *sk) +{ + struct sk_buff *skb; + int err; + + skb = sctp_skb_recv_datagram(sk, MSG_PEEK | MSG_DONTWAIT, &err); + if (skb != NULL) { + __sctp_ulpevent_read_nxtinfo(sctp_skb2event(skb), + msghdr, skb); + /* Just release refcount here. */ + kfree_skb(skb); + } +} + +/* 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); +} + +/* 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)); + } + +done: + sctp_assoc_rwnd_increase(event->asoc, len); + sctp_chunk_put(event->chunk); + sctp_ulpevent_release_owner(event); +} + +static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event) +{ + struct sk_buff *skb, *frag; + + skb = sctp_event2skb(event); + + 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)); + } + +done: + sctp_chunk_put(event->chunk); + 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. */ +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; +} |