[deliverable/linux.git] / net / sctp / chunk.c

/* SCTP kernel implementation
 * (C) Copyright IBM Corp. 2003, 2004
 *
 * This file is part of the SCTP kernel implementation
 *
 * This file contains the code relating the chunk abstraction.
 *
 * 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, 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 <linux-sctp@vger.kernel.org>
 *
 * Written or modified by:
 *    Jon Grimm             <jgrimm@us.ibm.com>
 *    Sridhar Samudrala     <sri@us.ibm.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/net.h>
#include <linux/inet.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>

/* This file is mostly in anticipation of future work, but initially
 * populate with fragment tracking for an outbound message.
 */

/* Initialize datamsg from memory. */
static void sctp_datamsg_init(struct sctp_datamsg *msg)
{
	atomic_set(&msg->refcnt, 1);
	msg->send_failed = 0;
	msg->send_error = 0;
	msg->can_abandon = 0;
	msg->can_delay = 1;
	msg->expires_at = 0;
	INIT_LIST_HEAD(&msg->chunks);
}

/* Allocate and initialize datamsg. */
static struct sctp_datamsg *sctp_datamsg_new(gfp_t gfp)
{
	struct sctp_datamsg *msg;
	msg = kmalloc(sizeof(struct sctp_datamsg), gfp);
	if (msg) {
		sctp_datamsg_init(msg);
		SCTP_DBG_OBJCNT_INC(datamsg);
	}
	return msg;
}

void sctp_datamsg_free(struct sctp_datamsg *msg)
{
	struct sctp_chunk *chunk;

	/* This doesn't have to be a _safe vairant because
	 * sctp_chunk_free() only drops the refs.
	 */
	list_for_each_entry(chunk, &msg->chunks, frag_list)
		sctp_chunk_free(chunk);

	sctp_datamsg_put(msg);
}

/* Final destructruction of datamsg memory. */
static void sctp_datamsg_destroy(struct sctp_datamsg *msg)
{
	struct list_head *pos, *temp;
	struct sctp_chunk *chunk;
	struct sctp_sock *sp;
	struct sctp_ulpevent *ev;
	struct sctp_association *asoc = NULL;
	int error = 0, notify;

	/* If we failed, we may need to notify. */
	notify = msg->send_failed ? -1 : 0;

	/* Release all references. */
	list_for_each_safe(pos, temp, &msg->chunks) {
		list_del_init(pos);
		chunk = list_entry(pos, struct sctp_chunk, frag_list);
		/* Check whether we _really_ need to notify. */
		if (notify < 0) {
			asoc = chunk->asoc;
			if (msg->send_error)
				error = msg->send_error;
			else
				error = asoc->outqueue.error;

			sp = sctp_sk(asoc->base.sk);
			notify = sctp_ulpevent_type_enabled(SCTP_SEND_FAILED,
							    &sp->subscribe);
		}

		/* Generate a SEND FAILED event only if enabled. */
		if (notify > 0) {
			int sent;
			if (chunk->has_tsn)
				sent = SCTP_DATA_SENT;
			else
				sent = SCTP_DATA_UNSENT;

			ev = sctp_ulpevent_make_send_failed(asoc, chunk, sent,
							    error, GFP_ATOMIC);
			if (ev)
				sctp_ulpq_tail_event(&asoc->ulpq, ev);
		}

		sctp_chunk_put(chunk);
	}

	SCTP_DBG_OBJCNT_DEC(datamsg);
	kfree(msg);
}

/* Hold a reference. */
static void sctp_datamsg_hold(struct sctp_datamsg *msg)
{
	atomic_inc(&msg->refcnt);
}

/* Release a reference. */
void sctp_datamsg_put(struct sctp_datamsg *msg)
{
	if (atomic_dec_and_test(&msg->refcnt))
		sctp_datamsg_destroy(msg);
}

/* Assign a chunk to this datamsg. */
static void sctp_datamsg_assign(struct sctp_datamsg *msg, struct sctp_chunk *chunk)
{
	sctp_datamsg_hold(msg);
	chunk->msg = msg;
}


/* A data chunk can have a maximum payload of (2^16 - 20).  Break
 * down any such message into smaller chunks.  Opportunistically, fragment
 * the chunks down to the current MTU constraints.  We may get refragmented
 * later if the PMTU changes, but it is _much better_ to fragment immediately
 * with a reasonable guess than always doing our fragmentation on the
 * soft-interrupt.
 */
struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
					    struct sctp_sndrcvinfo *sinfo,
					    struct msghdr *msgh, int msg_len)
{
	int max, whole, i, offset, over, err;
	int len, first_len;
	int max_data;
	struct sctp_chunk *chunk;
	struct sctp_datamsg *msg;
	struct list_head *pos, *temp;
	__u8 frag;

	msg = sctp_datamsg_new(GFP_KERNEL);
	if (!msg)
		return ERR_PTR(-ENOMEM);

	/* Note: Calculate this outside of the loop, so that all fragments
	 * have the same expiration.
	 */
	if (sinfo->sinfo_timetolive) {
		/* sinfo_timetolive is in milliseconds */
		msg->expires_at = jiffies +
				    msecs_to_jiffies(sinfo->sinfo_timetolive);
		msg->can_abandon = 1;

		pr_debug("%s: msg:%p expires_at:%ld jiffies:%ld\n", __func__,
			 msg, msg->expires_at, jiffies);
	}

	/* This is the biggest possible DATA chunk that can fit into
	 * the packet
	 */
	max_data = (asoc->pathmtu -
		sctp_sk(asoc->base.sk)->pf->af->net_header_len -
		sizeof(struct sctphdr) - sizeof(struct sctp_data_chunk)) & ~3;

	max = asoc->frag_point;
	/* If the the peer requested that we authenticate DATA chunks
	 * we need to accound for bundling of the AUTH chunks along with
	 * DATA.
	 */
	if (sctp_auth_send_cid(SCTP_CID_DATA, asoc)) {
		struct sctp_hmac *hmac_desc = sctp_auth_asoc_get_hmac(asoc);

		if (hmac_desc)
			max_data -= WORD_ROUND(sizeof(sctp_auth_chunk_t) +
					    hmac_desc->hmac_len);
	}

	/* Now, check if we need to reduce our max */
	if (max > max_data)
		max = max_data;

	whole = 0;
	first_len = max;

	/* Check to see if we have a pending SACK and try to let it be bundled
	 * with this message.  Do this if we don't have any data queued already.
	 * To check that, look at out_qlen and retransmit list.
	 * NOTE: we will not reduce to account for SACK, if the message would
	 * not have been fragmented.
	 */
	if (timer_pending(&asoc->timers[SCTP_EVENT_TIMEOUT_SACK]) &&
	    asoc->outqueue.out_qlen == 0 &&
	    list_empty(&asoc->outqueue.retransmit) &&
	    msg_len > max)
		max_data -= WORD_ROUND(sizeof(sctp_sack_chunk_t));

	/* Encourage Cookie-ECHO bundling. */
	if (asoc->state < SCTP_STATE_COOKIE_ECHOED)
		max_data -= SCTP_ARBITRARY_COOKIE_ECHO_LEN;

	/* Now that we adjusted completely, reset first_len */
	if (first_len > max_data)
		first_len = max_data;

	/* Account for a different sized first fragment */
	if (msg_len >= first_len) {
		msg_len -= first_len;
		whole = 1;
		msg->can_delay = 0;
	}

	/* How many full sized?  How many bytes leftover? */
	whole += msg_len / max;
	over = msg_len % max;
	offset = 0;

	if ((whole > 1) || (whole && over))
		SCTP_INC_STATS_USER(sock_net(asoc->base.sk), SCTP_MIB_FRAGUSRMSGS);

	/* Create chunks for all the full sized DATA chunks. */
	for (i=0, len=first_len; i < whole; i++) {
		frag = SCTP_DATA_MIDDLE_FRAG;

		if (0 == i)
			frag |= SCTP_DATA_FIRST_FRAG;

		if ((i == (whole - 1)) && !over) {
			frag |= SCTP_DATA_LAST_FRAG;

			/* The application requests to set the I-bit of the
			 * last DATA chunk of a user message when providing
			 * the user message to the SCTP implementation.
			 */
			if ((sinfo->sinfo_flags & SCTP_EOF) ||
			    (sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
				frag |= SCTP_DATA_SACK_IMM;
		}

		chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag, 0);

		if (!chunk) {
			err = -ENOMEM;
			goto errout;
		}

		err = sctp_user_addto_chunk(chunk, offset, len, msgh->msg_iov);
		if (err < 0)
			goto errout_chunk_free;

		offset += len;

		/* Put the chunk->skb back into the form expected by send.  */
		__skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
			   - (__u8 *)chunk->skb->data);

		sctp_datamsg_assign(msg, chunk);
		list_add_tail(&chunk->frag_list, &msg->chunks);

		/* The first chunk, the first chunk was likely short
		 * to allow bundling, so reset to full size.
		 */
		if (0 == i)
			len = max;
	}

	/* .. now the leftover bytes. */
	if (over) {
		if (!whole)
			frag = SCTP_DATA_NOT_FRAG;
		else
			frag = SCTP_DATA_LAST_FRAG;

		if ((sinfo->sinfo_flags & SCTP_EOF) ||
		    (sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
			frag |= SCTP_DATA_SACK_IMM;

		chunk = sctp_make_datafrag_empty(asoc, sinfo, over, frag, 0);

		if (!chunk) {
			err = -ENOMEM;
			goto errout;
		}

		err = sctp_user_addto_chunk(chunk, offset, over,msgh->msg_iov);

		/* Put the chunk->skb back into the form expected by send.  */
		__skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
			   - (__u8 *)chunk->skb->data);
		if (err < 0)
			goto errout_chunk_free;

		sctp_datamsg_assign(msg, chunk);
		list_add_tail(&chunk->frag_list, &msg->chunks);
	}

	return msg;

errout_chunk_free:
	sctp_chunk_free(chunk);

errout:
	list_for_each_safe(pos, temp, &msg->chunks) {
		list_del_init(pos);
		chunk = list_entry(pos, struct sctp_chunk, frag_list);
		sctp_chunk_free(chunk);
	}
	sctp_datamsg_put(msg);
	return ERR_PTR(err);
}

/* Check whether this message has expired. */
int sctp_chunk_abandoned(struct sctp_chunk *chunk)
{
	struct sctp_datamsg *msg = chunk->msg;

	if (!msg->can_abandon)
		return 0;

	if (time_after(jiffies, msg->expires_at))
		return 1;

	return 0;
}

/* This chunk (and consequently entire message) has failed in its sending. */
void sctp_chunk_fail(struct sctp_chunk *chunk, int error)
{
	chunk->msg->send_failed = 1;
	chunk->msg->send_error = error;
}
Commit	Line	Data
60c778b2	1	/* SCTP kernel implementation
1da177e4 LT	2	* (C) Copyright IBM Corp. 2003, 2004
1da177e4 LT	3	*
60c778b2	4	* This file is part of the SCTP kernel implementation
1da177e4	5	*
59c51591	6	* This file contains the code relating the chunk abstraction.
1da177e4	7	*
60c778b2	8	* This SCTP implementation is free software;
1da177e4 LT	9	* you can redistribute it and/or modify it under the terms of
	10	* the GNU General Public License as published by
	11	* the Free Software Foundation; either version 2, or (at your option)
	12	* any later version.
	13	*
60c778b2	14	* This SCTP implementation is distributed in the hope that it
1da177e4 LT	15	* will be useful, but WITHOUT ANY WARRANTY; without even the implied
	16	* ************************
	17	* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
	18	* See the GNU General Public License for more details.
	19	*
	20	* You should have received a copy of the GNU General Public License
	21	* along with GNU CC; see the file COPYING. If not, write to
	22	* the Free Software Foundation, 59 Temple Place - Suite 330,
	23	* Boston, MA 02111-1307, USA.
	24	*
	25	* Please send any bug reports or fixes you make to the
	26	* email address(es):
91705c61	27	* lksctp developers <linux-sctp@vger.kernel.org>
1da177e4	28	*
1da177e4 LT	29	* Written or modified by:
	30	* Jon Grimm <jgrimm@us.ibm.com>
	31	* Sridhar Samudrala <sri@us.ibm.com>
1da177e4 LT	32	*/
1da177e4 LT	33
145ce502 JP	34	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
145ce502 JP	35
1da177e4 LT	36	#include <linux/types.h>
	37	#include <linux/kernel.h>
	38	#include <linux/net.h>
	39	#include <linux/inet.h>
	40	#include <linux/skbuff.h>
5a0e3ad6	41	#include <linux/slab.h>
1da177e4 LT	42	#include <net/sock.h>
	43	#include <net/sctp/sctp.h>
	44	#include <net/sctp/sm.h>
	45
	46	/* This file is mostly in anticipation of future work, but initially
	47	* populate with fragment tracking for an outbound message.
	48	*/
	49
	50	/* Initialize datamsg from memory. */
	51	static void sctp_datamsg_init(struct sctp_datamsg *msg)
	52	{
	53	atomic_set(&msg->refcnt, 1);
	54	msg->send_failed = 0;
	55	msg->send_error = 0;
	56	msg->can_abandon = 0;
0e3aef8d	57	msg->can_delay = 1;
1da177e4 LT	58	msg->expires_at = 0;
	59	INIT_LIST_HEAD(&msg->chunks);
	60	}
	61
	62	/* Allocate and initialize datamsg. */
dda91928	63	static struct sctp_datamsg *sctp_datamsg_new(gfp_t gfp)
1da177e4 LT	64	{
	65	struct sctp_datamsg *msg;
	66	msg = kmalloc(sizeof(struct sctp_datamsg), gfp);
e8c38751	67	if (msg) {
1da177e4	68	sctp_datamsg_init(msg);
e8c38751 LZ	69	SCTP_DBG_OBJCNT_INC(datamsg);
e8c38751 LZ	70	}
1da177e4 LT	71	return msg;
	72	}
	73
9c5c62be VY	74	void sctp_datamsg_free(struct sctp_datamsg *msg)
	75	{
	76	struct sctp_chunk *chunk;
	77
	78	/* This doesn't have to be a _safe vairant because
	79	* sctp_chunk_free() only drops the refs.
	80	*/
	81	list_for_each_entry(chunk, &msg->chunks, frag_list)
	82	sctp_chunk_free(chunk);
	83
	84	sctp_datamsg_put(msg);
	85	}
	86
1da177e4 LT	87	/* Final destructruction of datamsg memory. */
	88	static void sctp_datamsg_destroy(struct sctp_datamsg *msg)
	89	{
	90	struct list_head pos, temp;
	91	struct sctp_chunk *chunk;
	92	struct sctp_sock *sp;
	93	struct sctp_ulpevent *ev;
	94	struct sctp_association *asoc = NULL;
	95	int error = 0, notify;
	96
	97	/* If we failed, we may need to notify. */
	98	notify = msg->send_failed ? -1 : 0;
	99
	100	/* Release all references. */
	101	list_for_each_safe(pos, temp, &msg->chunks) {
	102	list_del_init(pos);
	103	chunk = list_entry(pos, struct sctp_chunk, frag_list);
	104	/* Check whether we _really_ need to notify. */
	105	if (notify < 0) {
	106	asoc = chunk->asoc;
	107	if (msg->send_error)
	108	error = msg->send_error;
	109	else
	110	error = asoc->outqueue.error;
	111
	112	sp = sctp_sk(asoc->base.sk);
	113	notify = sctp_ulpevent_type_enabled(SCTP_SEND_FAILED,
	114	&sp->subscribe);
	115	}
	116
	117	/* Generate a SEND FAILED event only if enabled. */
	118	if (notify > 0) {
	119	int sent;
	120	if (chunk->has_tsn)
	121	sent = SCTP_DATA_SENT;
	122	else
	123	sent = SCTP_DATA_UNSENT;
	124
	125	ev = sctp_ulpevent_make_send_failed(asoc, chunk, sent,
	126	error, GFP_ATOMIC);
	127	if (ev)
	128	sctp_ulpq_tail_event(&asoc->ulpq, ev);
	129	}
	130
	131	sctp_chunk_put(chunk);
	132	}
	133
	134	SCTP_DBG_OBJCNT_DEC(datamsg);
	135	kfree(msg);
	136	}
	137
	138	/* Hold a reference. */
	139	static void sctp_datamsg_hold(struct sctp_datamsg *msg)
	140	{
	141	atomic_inc(&msg->refcnt);
	142	}
	143
	144	/* Release a reference. */
	145	void sctp_datamsg_put(struct sctp_datamsg *msg)
	146	{
	147	if (atomic_dec_and_test(&msg->refcnt))
	148	sctp_datamsg_destroy(msg);
	149	}
	150
1da177e4 LT	151	/* Assign a chunk to this datamsg. */
	152	static void sctp_datamsg_assign(struct sctp_datamsg msg, struct sctp_chunk chunk)
	153	{
	154	sctp_datamsg_hold(msg);
	155	chunk->msg = msg;
	156	}
	157
	158
	159	/* A data chunk can have a maximum payload of (2^16 - 20). Break
	160	* down any such message into smaller chunks. Opportunistically, fragment
	161	* the chunks down to the current MTU constraints. We may get refragmented
	162	* later if the PMTU changes, but it is _much better_ to fragment immediately
	163	* with a reasonable guess than always doing our fragmentation on the
	164	* soft-interrupt.
	165	*/
	166	struct sctp_datamsg sctp_datamsg_from_user(struct sctp_association asoc,
	167	struct sctp_sndrcvinfo *sinfo,
	168	struct msghdr *msgh, int msg_len)
	169	{
	170	int max, whole, i, offset, over, err;
	171	int len, first_len;
3e62abf9	172	int max_data;
1da177e4 LT	173	struct sctp_chunk *chunk;
	174	struct sctp_datamsg *msg;
	175	struct list_head pos, temp;
	176	__u8 frag;
	177
	178	msg = sctp_datamsg_new(GFP_KERNEL);
	179	if (!msg)
6e51fe75	180	return ERR_PTR(-ENOMEM);
1da177e4 LT	181
	182	/* Note: Calculate this outside of the loop, so that all fragments
	183	* have the same expiration.
	184	*/
	185	if (sinfo->sinfo_timetolive) {
	186	/* sinfo_timetolive is in milliseconds */
	187	msg->expires_at = jiffies +
	188	msecs_to_jiffies(sinfo->sinfo_timetolive);
	189	msg->can_abandon = 1;
bb33381d DB	190
	191	pr_debug("%s: msg:%p expires_at:%ld jiffies:%ld\n", __func__,
	192	msg, msg->expires_at, jiffies);
1da177e4 LT	193	}
1da177e4 LT	194
3e62abf9 VY	195	/* This is the biggest possible DATA chunk that can fit into
	196	* the packet
	197	*/
c08751c8	198	max_data = (asoc->pathmtu -
3e62abf9	199	sctp_sk(asoc->base.sk)->pf->af->net_header_len -
c08751c8	200	sizeof(struct sctphdr) - sizeof(struct sctp_data_chunk)) & ~3;
1da177e4	201
3e62abf9	202	max = asoc->frag_point;
4cd57c80 VY	203	/* If the the peer requested that we authenticate DATA chunks
	204	* we need to accound for bundling of the AUTH chunks along with
	205	* DATA.
	206	*/
	207	if (sctp_auth_send_cid(SCTP_CID_DATA, asoc)) {
	208	struct sctp_hmac *hmac_desc = sctp_auth_asoc_get_hmac(asoc);
	209
	210	if (hmac_desc)
3e62abf9	211	max_data -= WORD_ROUND(sizeof(sctp_auth_chunk_t) +
4cd57c80 VY	212	hmac_desc->hmac_len);
	213	}
	214
3e62abf9 VY	215	/* Now, check if we need to reduce our max */
	216	if (max > max_data)
	217	max = max_data;
	218
1da177e4 LT	219	whole = 0;
	220	first_len = max;
	221
5d7ff261 VY	222	/* Check to see if we have a pending SACK and try to let it be bundled
	223	* with this message. Do this if we don't have any data queued already.
	224	* To check that, look at out_qlen and retransmit list.
	225	* NOTE: we will not reduce to account for SACK, if the message would
	226	* not have been fragmented.
	227	*/
	228	if (timer_pending(&asoc->timers[SCTP_EVENT_TIMEOUT_SACK]) &&
	229	asoc->outqueue.out_qlen == 0 &&
	230	list_empty(&asoc->outqueue.retransmit) &&
	231	msg_len > max)
	232	max_data -= WORD_ROUND(sizeof(sctp_sack_chunk_t));
	233
1da177e4	234	/* Encourage Cookie-ECHO bundling. */
5d7ff261	235	if (asoc->state < SCTP_STATE_COOKIE_ECHOED)
3e62abf9	236	max_data -= SCTP_ARBITRARY_COOKIE_ECHO_LEN;
1da177e4	237
5d7ff261 VY	238	/* Now that we adjusted completely, reset first_len */
	239	if (first_len > max_data)
	240	first_len = max_data;
3e62abf9 VY	241
	242	/* Account for a different sized first fragment */
	243	if (msg_len >= first_len) {
	244	msg_len -= first_len;
	245	whole = 1;
0e3aef8d	246	msg->can_delay = 0;
1da177e4 LT	247	}
	248
	249	/* How many full sized? How many bytes leftover? */
	250	whole += msg_len / max;
	251	over = msg_len % max;
	252	offset = 0;
	253
	254	if ((whole > 1) \|\| (whole && over))
b01a2407	255	SCTP_INC_STATS_USER(sock_net(asoc->base.sk), SCTP_MIB_FRAGUSRMSGS);
1da177e4 LT	256
	257	/* Create chunks for all the full sized DATA chunks. */
	258	for (i=0, len=first_len; i < whole; i++) {
	259	frag = SCTP_DATA_MIDDLE_FRAG;
	260
	261	if (0 == i)
	262	frag \|= SCTP_DATA_FIRST_FRAG;
	263
b93d6471	264	if ((i == (whole - 1)) && !over) {
1da177e4 LT	265	frag \|= SCTP_DATA_LAST_FRAG;
1da177e4 LT	266
b93d6471 WY	267	/* The application requests to set the I-bit of the
	268	* last DATA chunk of a user message when providing
	269	* the user message to the SCTP implementation.
	270	*/
	271	if ((sinfo->sinfo_flags & SCTP_EOF) \|\|
	272	(sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
	273	frag \|= SCTP_DATA_SACK_IMM;
	274	}
	275
1da177e4 LT	276	chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag, 0);
1da177e4 LT	277
6e51fe75 TR	278	if (!chunk) {
6e51fe75 TR	279	err = -ENOMEM;
1da177e4	280	goto errout;
6e51fe75 TR	281	}
6e51fe75 TR	282
1da177e4 LT	283	err = sctp_user_addto_chunk(chunk, offset, len, msgh->msg_iov);
1da177e4 LT	284	if (err < 0)
be364c8c	285	goto errout_chunk_free;
1da177e4 LT	286
	287	offset += len;
	288
	289	/* Put the chunk->skb back into the form expected by send. */
	290	__skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
	291	- (__u8 *)chunk->skb->data);
	292
	293	sctp_datamsg_assign(msg, chunk);
	294	list_add_tail(&chunk->frag_list, &msg->chunks);
	295
	296	/* The first chunk, the first chunk was likely short
	297	* to allow bundling, so reset to full size.
	298	*/
	299	if (0 == i)
	300	len = max;
	301	}
	302
	303	/* .. now the leftover bytes. */
	304	if (over) {
	305	if (!whole)
	306	frag = SCTP_DATA_NOT_FRAG;
	307	else
	308	frag = SCTP_DATA_LAST_FRAG;
	309
b93d6471 WY	310	if ((sinfo->sinfo_flags & SCTP_EOF) \|\|
	311	(sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
	312	frag \|= SCTP_DATA_SACK_IMM;
	313
1da177e4 LT	314	chunk = sctp_make_datafrag_empty(asoc, sinfo, over, frag, 0);
1da177e4 LT	315
6e51fe75 TR	316	if (!chunk) {
6e51fe75 TR	317	err = -ENOMEM;
1da177e4	318	goto errout;
6e51fe75	319	}
1da177e4 LT	320
	321	err = sctp_user_addto_chunk(chunk, offset, over,msgh->msg_iov);
	322
	323	/* Put the chunk->skb back into the form expected by send. */
	324	__skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
	325	- (__u8 *)chunk->skb->data);
	326	if (err < 0)
be364c8c	327	goto errout_chunk_free;
1da177e4 LT	328
	329	sctp_datamsg_assign(msg, chunk);
	330	list_add_tail(&chunk->frag_list, &msg->chunks);
	331	}
	332
	333	return msg;
	334
be364c8c TR	335	errout_chunk_free:
	336	sctp_chunk_free(chunk);
	337
1da177e4 LT	338	errout:
	339	list_for_each_safe(pos, temp, &msg->chunks) {
	340	list_del_init(pos);
	341	chunk = list_entry(pos, struct sctp_chunk, frag_list);
	342	sctp_chunk_free(chunk);
	343	}
80445cfb	344	sctp_datamsg_put(msg);
6e51fe75	345	return ERR_PTR(err);
1da177e4 LT	346	}
	347
	348	/* Check whether this message has expired. */
	349	int sctp_chunk_abandoned(struct sctp_chunk *chunk)
	350	{
	351	struct sctp_datamsg *msg = chunk->msg;
	352
	353	if (!msg->can_abandon)
	354	return 0;
	355
	356	if (time_after(jiffies, msg->expires_at))
	357	return 1;
	358
	359	return 0;
	360	}
	361
	362	/* This chunk (and consequently entire message) has failed in its sending. */
	363	void sctp_chunk_fail(struct sctp_chunk *chunk, int error)
	364	{
	365	chunk->msg->send_failed = 1;
	366	chunk->msg->send_error = error;
	367	}