linux/net/sctp/stream_interleave.c

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/* SCTP kernel implementation
* (C) Copyright Red Hat Inc. 2017
*
* This file is part of the SCTP kernel implementation
*
* These functions manipulate sctp stream queue/scheduling.
*
* This SCTP 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.
*
* This SCTP 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, see
* <http://www.gnu.org/licenses/>.
*
* Please send any bug reports or fixes you make to the
* email addresched(es):
* lksctp developers <linux-sctp@vger.kernel.org>
*
* Written or modified by:
* Xin Long <lucien.xin@gmail.com>
*/
#include <net/busy_poll.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>
#include <net/sctp/ulpevent.h>
#include <linux/sctp.h>
static struct sctp_chunk *sctp_make_idatafrag_empty(
const struct sctp_association *asoc,
const struct sctp_sndrcvinfo *sinfo,
int len, __u8 flags, gfp_t gfp)
{
struct sctp_chunk *retval;
struct sctp_idatahdr dp;
memset(&dp, 0, sizeof(dp));
dp.stream = htons(sinfo->sinfo_stream);
if (sinfo->sinfo_flags & SCTP_UNORDERED)
flags |= SCTP_DATA_UNORDERED;
retval = sctp_make_idata(asoc, flags, sizeof(dp) + len, gfp);
if (!retval)
return NULL;
retval->subh.idata_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
return retval;
}
static void sctp_chunk_assign_mid(struct sctp_chunk *chunk)
{
struct sctp_stream *stream;
struct sctp_chunk *lchunk;
__u32 cfsn = 0;
__u16 sid;
if (chunk->has_mid)
return;
sid = sctp_chunk_stream_no(chunk);
stream = &chunk->asoc->stream;
list_for_each_entry(lchunk, &chunk->msg->chunks, frag_list) {
struct sctp_idatahdr *hdr;
lchunk->has_mid = 1;
if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
continue;
hdr = lchunk->subh.idata_hdr;
if (lchunk->chunk_hdr->flags & SCTP_DATA_FIRST_FRAG)
hdr->ppid = lchunk->sinfo.sinfo_ppid;
else
hdr->fsn = htonl(cfsn++);
if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
hdr->mid = htonl(sctp_mid_next(stream, out, sid));
else
hdr->mid = htonl(sctp_mid_peek(stream, out, sid));
}
}
static bool sctp_validate_data(struct sctp_chunk *chunk)
{
const struct sctp_stream *stream;
__u16 sid, ssn;
if (chunk->chunk_hdr->type != SCTP_CID_DATA)
return false;
if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
return true;
stream = &chunk->asoc->stream;
sid = sctp_chunk_stream_no(chunk);
ssn = ntohs(chunk->subh.data_hdr->ssn);
return !SSN_lt(ssn, sctp_ssn_peek(stream, in, sid));
}
static bool sctp_validate_idata(struct sctp_chunk *chunk)
{
struct sctp_stream *stream;
__u32 mid;
__u16 sid;
if (chunk->chunk_hdr->type != SCTP_CID_I_DATA)
return false;
if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
return true;
stream = &chunk->asoc->stream;
sid = sctp_chunk_stream_no(chunk);
mid = ntohl(chunk->subh.idata_hdr->mid);
return !MID_lt(mid, sctp_mid_peek(stream, in, sid));
}
static void sctp_intl_store_reasm(struct sctp_ulpq *ulpq,
struct sctp_ulpevent *event)
{
struct sctp_ulpevent *cevent;
struct sk_buff *pos;
pos = skb_peek_tail(&ulpq->reasm);
if (!pos) {
__skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
return;
}
cevent = sctp_skb2event(pos);
if (event->stream == cevent->stream &&
event->mid == cevent->mid &&
(cevent->msg_flags & SCTP_DATA_FIRST_FRAG ||
(!(event->msg_flags & SCTP_DATA_FIRST_FRAG) &&
event->fsn > cevent->fsn))) {
__skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
return;
}
if ((event->stream == cevent->stream &&
MID_lt(cevent->mid, event->mid)) ||
event->stream > cevent->stream) {
__skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
return;
}
skb_queue_walk(&ulpq->reasm, pos) {
cevent = sctp_skb2event(pos);
if (event->stream < cevent->stream ||
(event->stream == cevent->stream &&
MID_lt(event->mid, cevent->mid)))
break;
if (event->stream == cevent->stream &&
event->mid == cevent->mid &&
!(cevent->msg_flags & SCTP_DATA_FIRST_FRAG) &&
(event->msg_flags & SCTP_DATA_FIRST_FRAG ||
event->fsn < cevent->fsn))
break;
}
__skb_queue_before(&ulpq->reasm, pos, sctp_event2skb(event));
}
static struct sctp_ulpevent *sctp_intl_retrieve_partial(
struct sctp_ulpq *ulpq,
struct sctp_ulpevent *event)
{
struct sk_buff *first_frag = NULL;
struct sk_buff *last_frag = NULL;
struct sctp_ulpevent *retval;
struct sctp_stream_in *sin;
struct sk_buff *pos;
__u32 next_fsn = 0;
int is_last = 0;
sin = sctp_stream_in(ulpq->asoc, event->stream);
skb_queue_walk(&ulpq->reasm, pos) {
struct sctp_ulpevent *cevent = sctp_skb2event(pos);
if (cevent->stream < event->stream)
continue;
if (cevent->stream > event->stream ||
cevent->mid != sin->mid)
break;
switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
case SCTP_DATA_FIRST_FRAG:
goto out;
case SCTP_DATA_MIDDLE_FRAG:
if (!first_frag) {
if (cevent->fsn == sin->fsn) {
first_frag = pos;
last_frag = pos;
next_fsn = cevent->fsn + 1;
}
} else if (cevent->fsn == next_fsn) {
last_frag = pos;
next_fsn++;
} else {
goto out;
}
break;
case SCTP_DATA_LAST_FRAG:
if (!first_frag) {
if (cevent->fsn == sin->fsn) {
first_frag = pos;
last_frag = pos;
next_fsn = 0;
is_last = 1;
}
} else if (cevent->fsn == next_fsn) {
last_frag = pos;
next_fsn = 0;
is_last = 1;
}
goto out;
default:
goto out;
}
}
out:
if (!first_frag)
return NULL;
retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
&ulpq->reasm, first_frag,
last_frag);
if (retval) {
sin->fsn = next_fsn;
if (is_last) {
retval->msg_flags |= MSG_EOR;
sin->pd_mode = 0;
}
}
return retval;
}
static struct sctp_ulpevent *sctp_intl_retrieve_reassembled(
struct sctp_ulpq *ulpq,
struct sctp_ulpevent *event)
{
struct sctp_association *asoc = ulpq->asoc;
struct sk_buff *pos, *first_frag = NULL;
struct sctp_ulpevent *retval = NULL;
struct sk_buff *pd_first = NULL;
struct sk_buff *pd_last = NULL;
struct sctp_stream_in *sin;
__u32 next_fsn = 0;
__u32 pd_point = 0;
__u32 pd_len = 0;
__u32 mid = 0;
sin = sctp_stream_in(ulpq->asoc, event->stream);
skb_queue_walk(&ulpq->reasm, pos) {
struct sctp_ulpevent *cevent = sctp_skb2event(pos);
if (cevent->stream < event->stream)
continue;
if (cevent->stream > event->stream)
break;
if (MID_lt(cevent->mid, event->mid))
continue;
if (MID_lt(event->mid, cevent->mid))
break;
switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
case SCTP_DATA_FIRST_FRAG:
if (cevent->mid == sin->mid) {
pd_first = pos;
pd_last = pos;
pd_len = pos->len;
}
first_frag = pos;
next_fsn = 0;
mid = cevent->mid;
break;
case SCTP_DATA_MIDDLE_FRAG:
if (first_frag && cevent->mid == mid &&
cevent->fsn == next_fsn) {
next_fsn++;
if (pd_first) {
pd_last = pos;
pd_len += pos->len;
}
} else {
first_frag = NULL;
}
break;
case SCTP_DATA_LAST_FRAG:
if (first_frag && cevent->mid == mid &&
cevent->fsn == next_fsn)
goto found;
else
first_frag = NULL;
break;
}
}
if (!pd_first)
goto out;
pd_point = sctp_sk(asoc->base.sk)->pd_point;
if (pd_point && pd_point <= pd_len) {
retval = sctp_make_reassembled_event(sock_net(asoc->base.sk),
&ulpq->reasm,
pd_first, pd_last);
if (retval) {
sin->fsn = next_fsn;
sin->pd_mode = 1;
}
}
goto out;
found:
retval = sctp_make_reassembled_event(sock_net(asoc->base.sk),
&ulpq->reasm,
first_frag, pos);
if (retval)
retval->msg_flags |= MSG_EOR;
out:
return retval;
}
static struct sctp_ulpevent *sctp_intl_reasm(struct sctp_ulpq *ulpq,
struct sctp_ulpevent *event)
{
struct sctp_ulpevent *retval = NULL;
struct sctp_stream_in *sin;
if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) {
event->msg_flags |= MSG_EOR;
return event;
}
sctp_intl_store_reasm(ulpq, event);
sin = sctp_stream_in(ulpq->asoc, event->stream);
if (sin->pd_mode && event->mid == sin->mid &&
event->fsn == sin->fsn)
retval = sctp_intl_retrieve_partial(ulpq, event);
if (!retval)
retval = sctp_intl_retrieve_reassembled(ulpq, event);
return retval;
}
static void sctp_intl_store_ordered(struct sctp_ulpq *ulpq,
struct sctp_ulpevent *event)
{
struct sctp_ulpevent *cevent;
struct sk_buff *pos;
pos = skb_peek_tail(&ulpq->lobby);
if (!pos) {
__skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
return;
}
cevent = (struct sctp_ulpevent *)pos->cb;
if (event->stream == cevent->stream &&
MID_lt(cevent->mid, event->mid)) {
__skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
return;
}
if (event->stream > cevent->stream) {
__skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
return;
}
skb_queue_walk(&ulpq->lobby, pos) {
cevent = (struct sctp_ulpevent *)pos->cb;
if (cevent->stream > event->stream)
break;
if (cevent->stream == event->stream &&
MID_lt(event->mid, cevent->mid))
break;
}
__skb_queue_before(&ulpq->lobby, pos, sctp_event2skb(event));
}
static void sctp_intl_retrieve_ordered(struct sctp_ulpq *ulpq,
struct sctp_ulpevent *event)
{
struct sk_buff_head *event_list;
struct sctp_stream *stream;
struct sk_buff *pos, *tmp;
__u16 sid = event->stream;
stream = &ulpq->asoc->stream;
event_list = (struct sk_buff_head *)sctp_event2skb(event)->prev;
sctp_skb_for_each(pos, &ulpq->lobby, tmp) {
struct sctp_ulpevent *cevent = (struct sctp_ulpevent *)pos->cb;
if (cevent->stream > sid)
break;
if (cevent->stream < sid)
continue;
if (cevent->mid != sctp_mid_peek(stream, in, sid))
break;
sctp_mid_next(stream, in, sid);
__skb_unlink(pos, &ulpq->lobby);
__skb_queue_tail(event_list, pos);
}
}
static struct sctp_ulpevent *sctp_intl_order(struct sctp_ulpq *ulpq,
struct sctp_ulpevent *event)
{
struct sctp_stream *stream;
__u16 sid;
if (event->msg_flags & SCTP_DATA_UNORDERED)
return event;
stream = &ulpq->asoc->stream;
sid = event->stream;
if (event->mid != sctp_mid_peek(stream, in, sid)) {
sctp_intl_store_ordered(ulpq, event);
return NULL;
}
sctp_mid_next(stream, in, sid);
sctp_intl_retrieve_ordered(ulpq, event);
return event;
}
static int sctp_enqueue_event(struct sctp_ulpq *ulpq,
struct sctp_ulpevent *event)
{
struct sk_buff *skb = sctp_event2skb(event);
struct sock *sk = ulpq->asoc->base.sk;
struct sctp_sock *sp = sctp_sk(sk);
struct sk_buff_head *skb_list;
skb_list = (struct sk_buff_head *)skb->prev;
if (sk->sk_shutdown & RCV_SHUTDOWN &&
(sk->sk_shutdown & SEND_SHUTDOWN ||
!sctp_ulpevent_is_notification(event)))
goto out_free;
if (!sctp_ulpevent_is_notification(event)) {
sk_mark_napi_id(sk, skb);
sk_incoming_cpu_update(sk);
}
if (!sctp_ulpevent_is_enabled(event, &sp->subscribe))
goto out_free;
if (skb_list)
skb_queue_splice_tail_init(skb_list,
&sk->sk_receive_queue);
else
__skb_queue_tail(&sk->sk_receive_queue, skb);
if (!sp->data_ready_signalled) {
sp->data_ready_signalled = 1;
sk->sk_data_ready(sk);
}
return 1;
out_free:
if (skb_list)
sctp_queue_purge_ulpevents(skb_list);
else
sctp_ulpevent_free(event);
return 0;
}
static int sctp_ulpevent_idata(struct sctp_ulpq *ulpq,
struct sctp_chunk *chunk, gfp_t gfp)
{
struct sctp_ulpevent *event;
struct sk_buff_head temp;
int event_eor = 0;
event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp);
if (!event)
return -ENOMEM;
event->mid = ntohl(chunk->subh.idata_hdr->mid);
if (event->msg_flags & SCTP_DATA_FIRST_FRAG)
event->ppid = chunk->subh.idata_hdr->ppid;
else
event->fsn = ntohl(chunk->subh.idata_hdr->fsn);
event = sctp_intl_reasm(ulpq, event);
if (event && event->msg_flags & MSG_EOR) {
skb_queue_head_init(&temp);
__skb_queue_tail(&temp, sctp_event2skb(event));
event = sctp_intl_order(ulpq, event);
}
if (event) {
event_eor = (event->msg_flags & MSG_EOR) ? 1 : 0;
sctp_enqueue_event(ulpq, event);
}
return event_eor;
}
static struct sctp_ulpevent *sctp_intl_retrieve_first(struct sctp_ulpq *ulpq)
{
struct sctp_stream_in *csin, *sin = NULL;
struct sk_buff *first_frag = NULL;
struct sk_buff *last_frag = NULL;
struct sctp_ulpevent *retval;
struct sk_buff *pos;
__u32 next_fsn = 0;
__u16 sid = 0;
skb_queue_walk(&ulpq->reasm, pos) {
struct sctp_ulpevent *cevent = sctp_skb2event(pos);
csin = sctp_stream_in(ulpq->asoc, cevent->stream);
if (csin->pd_mode)
continue;
switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
case SCTP_DATA_FIRST_FRAG:
if (first_frag)
goto out;
if (cevent->mid == csin->mid) {
first_frag = pos;
last_frag = pos;
next_fsn = 0;
sin = csin;
sid = cevent->stream;
}
break;
case SCTP_DATA_MIDDLE_FRAG:
if (!first_frag)
break;
if (cevent->stream == sid &&
cevent->mid == sin->mid &&
cevent->fsn == next_fsn) {
next_fsn++;
last_frag = pos;
} else {
goto out;
}
break;
case SCTP_DATA_LAST_FRAG:
if (first_frag)
goto out;
break;
default:
break;
}
}
if (!first_frag)
return NULL;
out:
retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
&ulpq->reasm, first_frag,
last_frag);
if (retval) {
sin->fsn = next_fsn;
sin->pd_mode = 1;
}
return retval;
}
static void sctp_intl_start_pd(struct sctp_ulpq *ulpq, gfp_t gfp)
{
struct sctp_ulpevent *event;
if (skb_queue_empty(&ulpq->reasm))
return;
do {
event = sctp_intl_retrieve_first(ulpq);
if (event)
sctp_enqueue_event(ulpq, event);
} while (event);
}
static void sctp_renege_events(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
gfp_t gfp)
{
struct sctp_association *asoc = ulpq->asoc;
__u32 freed = 0;
__u16 needed;
if (chunk) {
needed = ntohs(chunk->chunk_hdr->length);
needed -= sizeof(struct sctp_idata_chunk);
} else {
needed = SCTP_DEFAULT_MAXWINDOW;
}
if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) {
freed = sctp_ulpq_renege_list(ulpq, &ulpq->lobby, needed);
if (freed < needed)
freed += sctp_ulpq_renege_list(ulpq, &ulpq->reasm,
needed);
}
if (chunk && freed >= needed)
if (sctp_ulpevent_idata(ulpq, chunk, gfp) <= 0)
sctp_intl_start_pd(ulpq, gfp);
sk_mem_reclaim(asoc->base.sk);
}
static struct sctp_stream_interleave sctp_stream_interleave_0 = {
.data_chunk_len = sizeof(struct sctp_data_chunk),
/* DATA process functions */
.make_datafrag = sctp_make_datafrag_empty,
.assign_number = sctp_chunk_assign_ssn,
.validate_data = sctp_validate_data,
.ulpevent_data = sctp_ulpq_tail_data,
.enqueue_event = sctp_ulpq_tail_event,
.renege_events = sctp_ulpq_renege,
.start_pd = sctp_ulpq_partial_delivery,
};
static struct sctp_stream_interleave sctp_stream_interleave_1 = {
.data_chunk_len = sizeof(struct sctp_idata_chunk),
/* I-DATA process functions */
.make_datafrag = sctp_make_idatafrag_empty,
.assign_number = sctp_chunk_assign_mid,
.validate_data = sctp_validate_idata,
.ulpevent_data = sctp_ulpevent_idata,
.enqueue_event = sctp_enqueue_event,
.renege_events = sctp_renege_events,
.start_pd = sctp_intl_start_pd,
};
void sctp_stream_interleave_init(struct sctp_stream *stream)
{
struct sctp_association *asoc;
asoc = container_of(stream, struct sctp_association, stream);
stream->si = asoc->intl_enable ? &sctp_stream_interleave_1
: &sctp_stream_interleave_0;
}