linux/net/sctp/stream_interleave.c
Xin Long 0c3f6f6554 sctp: implement make_datafrag for sctp_stream_interleave
To avoid hundreds of checks for the different process on I-DATA chunk,
struct sctp_stream_interleave is defined as a group of functions used
to replace the codes in some place where it needs to do different job
according to if the asoc intl_enabled is set.

With these ops, it only needs to initialize asoc->stream.si with
sctp_stream_interleave_0 for normal data if asoc intl_enable is 0,
or sctp_stream_interleave_1 for idata if asoc intl_enable is set in
sctp_stream_init.

After that, the members in asoc->stream.si can be used directly in
some special places without checking asoc intl_enable.

make_datafrag is the first member for sctp_stream_interleave, it's
used to make data or idata frags, called in sctp_datamsg_from_user.
The old function sctp_make_datafrag_empty needs to be adjust some
to fit in this ops.

Note that as idata and data chunks have different length, it also
defines data_chunk_len for sctp_stream_interleave to describe the
chunk size.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11 11:23:04 -05:00

80 lines
2.4 KiB
C

/* 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/sctp/sctp.h>
#include <net/sctp/sm.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 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,
};
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,
};
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;
}