[net-next-2.6.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 <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>
 *    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.
 */

#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. */
SCTP_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 NULL;

	/* 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;
		SCTP_DEBUG_PRINTK("%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);

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

		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)
			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;

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

	return msg;

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 NULL;
}

/* 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):
	27	* lksctp developers <lksctp-developers@lists.sourceforge.net>
	28	*
	29	* Or submit a bug report through the following website:
	30	* http://www.sf.net/projects/lksctp
	31	*
	32	* Written or modified by:
	33	* Jon Grimm <jgrimm@us.ibm.com>
	34	* Sridhar Samudrala <sri@us.ibm.com>
	35	*
	36	* Any bugs reported given to us we will try to fix... any fixes shared will
	37	* be incorporated into the next SCTP release.
	38	*/
	39
145ce502 JP	40	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
145ce502 JP	41
1da177e4 LT	42	#include <linux/types.h>
	43	#include <linux/kernel.h>
	44	#include <linux/net.h>
	45	#include <linux/inet.h>
	46	#include <linux/skbuff.h>
5a0e3ad6	47	#include <linux/slab.h>
1da177e4 LT	48	#include <net/sock.h>
	49	#include <net/sctp/sctp.h>
	50	#include <net/sctp/sm.h>
	51
	52	/* This file is mostly in anticipation of future work, but initially
	53	* populate with fragment tracking for an outbound message.
	54	*/
	55
	56	/* Initialize datamsg from memory. */
	57	static void sctp_datamsg_init(struct sctp_datamsg *msg)
	58	{
	59	atomic_set(&msg->refcnt, 1);
	60	msg->send_failed = 0;
	61	msg->send_error = 0;
	62	msg->can_abandon = 0;
0e3aef8d	63	msg->can_delay = 1;
1da177e4 LT	64	msg->expires_at = 0;
	65	INIT_LIST_HEAD(&msg->chunks);
	66	}
	67
	68	/* Allocate and initialize datamsg. */
dd0fc66f	69	SCTP_STATIC struct sctp_datamsg *sctp_datamsg_new(gfp_t gfp)
1da177e4 LT	70	{
	71	struct sctp_datamsg *msg;
	72	msg = kmalloc(sizeof(struct sctp_datamsg), gfp);
e8c38751	73	if (msg) {
1da177e4	74	sctp_datamsg_init(msg);
e8c38751 LZ	75	SCTP_DBG_OBJCNT_INC(datamsg);
e8c38751 LZ	76	}
1da177e4 LT	77	return msg;
	78	}
	79
9c5c62be VY	80	void sctp_datamsg_free(struct sctp_datamsg *msg)
	81	{
	82	struct sctp_chunk *chunk;
	83
	84	/* This doesn't have to be a _safe vairant because
	85	* sctp_chunk_free() only drops the refs.
	86	*/
	87	list_for_each_entry(chunk, &msg->chunks, frag_list)
	88	sctp_chunk_free(chunk);
	89
	90	sctp_datamsg_put(msg);
	91	}
	92
1da177e4 LT	93	/* Final destructruction of datamsg memory. */
	94	static void sctp_datamsg_destroy(struct sctp_datamsg *msg)
	95	{
	96	struct list_head pos, temp;
	97	struct sctp_chunk *chunk;
	98	struct sctp_sock *sp;
	99	struct sctp_ulpevent *ev;
	100	struct sctp_association *asoc = NULL;
	101	int error = 0, notify;
	102
	103	/* If we failed, we may need to notify. */
	104	notify = msg->send_failed ? -1 : 0;
	105
	106	/* Release all references. */
	107	list_for_each_safe(pos, temp, &msg->chunks) {
	108	list_del_init(pos);
	109	chunk = list_entry(pos, struct sctp_chunk, frag_list);
	110	/* Check whether we _really_ need to notify. */
	111	if (notify < 0) {
	112	asoc = chunk->asoc;
	113	if (msg->send_error)
	114	error = msg->send_error;
	115	else
	116	error = asoc->outqueue.error;
	117
	118	sp = sctp_sk(asoc->base.sk);
	119	notify = sctp_ulpevent_type_enabled(SCTP_SEND_FAILED,
	120	&sp->subscribe);
	121	}
	122
	123	/* Generate a SEND FAILED event only if enabled. */
	124	if (notify > 0) {
	125	int sent;
	126	if (chunk->has_tsn)
	127	sent = SCTP_DATA_SENT;
	128	else
	129	sent = SCTP_DATA_UNSENT;
	130
	131	ev = sctp_ulpevent_make_send_failed(asoc, chunk, sent,
	132	error, GFP_ATOMIC);
	133	if (ev)
	134	sctp_ulpq_tail_event(&asoc->ulpq, ev);
	135	}
	136
	137	sctp_chunk_put(chunk);
	138	}
	139
	140	SCTP_DBG_OBJCNT_DEC(datamsg);
	141	kfree(msg);
	142	}
	143
	144	/* Hold a reference. */
	145	static void sctp_datamsg_hold(struct sctp_datamsg *msg)
	146	{
	147	atomic_inc(&msg->refcnt);
	148	}
	149
	150	/* Release a reference. */
	151	void sctp_datamsg_put(struct sctp_datamsg *msg)
	152	{
	153	if (atomic_dec_and_test(&msg->refcnt))
	154	sctp_datamsg_destroy(msg);
	155	}
	156
1da177e4 LT	157	/* Assign a chunk to this datamsg. */
	158	static void sctp_datamsg_assign(struct sctp_datamsg msg, struct sctp_chunk chunk)
	159	{
	160	sctp_datamsg_hold(msg);
	161	chunk->msg = msg;
	162	}
	163
	164
	165	/* A data chunk can have a maximum payload of (2^16 - 20). Break
	166	* down any such message into smaller chunks. Opportunistically, fragment
	167	* the chunks down to the current MTU constraints. We may get refragmented
	168	* later if the PMTU changes, but it is _much better_ to fragment immediately
	169	* with a reasonable guess than always doing our fragmentation on the
	170	* soft-interrupt.
	171	*/
	172	struct sctp_datamsg sctp_datamsg_from_user(struct sctp_association asoc,
	173	struct sctp_sndrcvinfo *sinfo,
	174	struct msghdr *msgh, int msg_len)
	175	{
	176	int max, whole, i, offset, over, err;
	177	int len, first_len;
3e62abf9	178	int max_data;
1da177e4 LT	179	struct sctp_chunk *chunk;
	180	struct sctp_datamsg *msg;
	181	struct list_head pos, temp;
	182	__u8 frag;
	183
	184	msg = sctp_datamsg_new(GFP_KERNEL);
	185	if (!msg)
	186	return NULL;
	187
	188	/* Note: Calculate this outside of the loop, so that all fragments
	189	* have the same expiration.
	190	*/
	191	if (sinfo->sinfo_timetolive) {
	192	/* sinfo_timetolive is in milliseconds */
	193	msg->expires_at = jiffies +
	194	msecs_to_jiffies(sinfo->sinfo_timetolive);
	195	msg->can_abandon = 1;
	196	SCTP_DEBUG_PRINTK("%s: msg:%p expires_at: %ld jiffies:%ld\n",
0dc47877	197	__func__, msg, msg->expires_at, jiffies);
1da177e4 LT	198	}
1da177e4 LT	199
3e62abf9 VY	200	/* This is the biggest possible DATA chunk that can fit into
	201	* the packet
	202	*/
	203	max_data = asoc->pathmtu -
	204	sctp_sk(asoc->base.sk)->pf->af->net_header_len -
	205	sizeof(struct sctphdr) - sizeof(struct sctp_data_chunk);
1da177e4	206
3e62abf9	207	max = asoc->frag_point;
4cd57c80 VY	208	/* If the the peer requested that we authenticate DATA chunks
	209	* we need to accound for bundling of the AUTH chunks along with
	210	* DATA.
	211	*/
	212	if (sctp_auth_send_cid(SCTP_CID_DATA, asoc)) {
	213	struct sctp_hmac *hmac_desc = sctp_auth_asoc_get_hmac(asoc);
	214
	215	if (hmac_desc)
3e62abf9	216	max_data -= WORD_ROUND(sizeof(sctp_auth_chunk_t) +
4cd57c80 VY	217	hmac_desc->hmac_len);
	218	}
	219
3e62abf9 VY	220	/* Now, check if we need to reduce our max */
	221	if (max > max_data)
	222	max = max_data;
	223
1da177e4 LT	224	whole = 0;
	225	first_len = max;
	226
5d7ff261 VY	227	/* Check to see if we have a pending SACK and try to let it be bundled
	228	* with this message. Do this if we don't have any data queued already.
	229	* To check that, look at out_qlen and retransmit list.
	230	* NOTE: we will not reduce to account for SACK, if the message would
	231	* not have been fragmented.
	232	*/
	233	if (timer_pending(&asoc->timers[SCTP_EVENT_TIMEOUT_SACK]) &&
	234	asoc->outqueue.out_qlen == 0 &&
	235	list_empty(&asoc->outqueue.retransmit) &&
	236	msg_len > max)
	237	max_data -= WORD_ROUND(sizeof(sctp_sack_chunk_t));
	238
1da177e4	239	/* Encourage Cookie-ECHO bundling. */
5d7ff261	240	if (asoc->state < SCTP_STATE_COOKIE_ECHOED)
3e62abf9	241	max_data -= SCTP_ARBITRARY_COOKIE_ECHO_LEN;
1da177e4	242
5d7ff261 VY	243	/* Now that we adjusted completely, reset first_len */
	244	if (first_len > max_data)
	245	first_len = max_data;
3e62abf9 VY	246
	247	/* Account for a different sized first fragment */
	248	if (msg_len >= first_len) {
	249	msg_len -= first_len;
	250	whole = 1;
0e3aef8d	251	msg->can_delay = 0;
1da177e4 LT	252	}
	253
	254	/* How many full sized? How many bytes leftover? */
	255	whole += msg_len / max;
	256	over = msg_len % max;
	257	offset = 0;
	258
	259	if ((whole > 1) \|\| (whole && over))
	260	SCTP_INC_STATS_USER(SCTP_MIB_FRAGUSRMSGS);
	261
	262	/* Create chunks for all the full sized DATA chunks. */
	263	for (i=0, len=first_len; i < whole; i++) {
	264	frag = SCTP_DATA_MIDDLE_FRAG;
	265
	266	if (0 == i)
	267	frag \|= SCTP_DATA_FIRST_FRAG;
	268
b93d6471	269	if ((i == (whole - 1)) && !over) {
1da177e4 LT	270	frag \|= SCTP_DATA_LAST_FRAG;
1da177e4 LT	271
b93d6471 WY	272	/* The application requests to set the I-bit of the
	273	* last DATA chunk of a user message when providing
	274	* the user message to the SCTP implementation.
	275	*/
	276	if ((sinfo->sinfo_flags & SCTP_EOF) \|\|
	277	(sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
	278	frag \|= SCTP_DATA_SACK_IMM;
	279	}
	280
1da177e4 LT	281	chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag, 0);
	282
	283	if (!chunk)
	284	goto errout;
	285	err = sctp_user_addto_chunk(chunk, offset, len, msgh->msg_iov);
	286	if (err < 0)
	287	goto errout;
	288
	289	offset += len;
	290
	291	/* Put the chunk->skb back into the form expected by send. */
	292	__skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
	293	- (__u8 *)chunk->skb->data);
	294
	295	sctp_datamsg_assign(msg, chunk);
	296	list_add_tail(&chunk->frag_list, &msg->chunks);
	297
	298	/* The first chunk, the first chunk was likely short
	299	* to allow bundling, so reset to full size.
	300	*/
	301	if (0 == i)
	302	len = max;
	303	}
	304
	305	/* .. now the leftover bytes. */
	306	if (over) {
	307	if (!whole)
	308	frag = SCTP_DATA_NOT_FRAG;
	309	else
	310	frag = SCTP_DATA_LAST_FRAG;
	311
b93d6471 WY	312	if ((sinfo->sinfo_flags & SCTP_EOF) \|\|
	313	(sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
	314	frag \|= SCTP_DATA_SACK_IMM;
	315
1da177e4 LT	316	chunk = sctp_make_datafrag_empty(asoc, sinfo, over, frag, 0);
	317
	318	if (!chunk)
	319	goto errout;
	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)
	327	goto errout;
	328
	329	sctp_datamsg_assign(msg, chunk);
	330	list_add_tail(&chunk->frag_list, &msg->chunks);
	331	}
	332
	333	return msg;
	334
	335	errout:
	336	list_for_each_safe(pos, temp, &msg->chunks) {
	337	list_del_init(pos);
	338	chunk = list_entry(pos, struct sctp_chunk, frag_list);
	339	sctp_chunk_free(chunk);
	340	}
80445cfb	341	sctp_datamsg_put(msg);
1da177e4 LT	342	return NULL;
	343	}
	344
	345	/* Check whether this message has expired. */
	346	int sctp_chunk_abandoned(struct sctp_chunk *chunk)
	347	{
	348	struct sctp_datamsg *msg = chunk->msg;
	349
	350	if (!msg->can_abandon)
	351	return 0;
	352
	353	if (time_after(jiffies, msg->expires_at))
	354	return 1;
	355
	356	return 0;
	357	}
	358
	359	/* This chunk (and consequently entire message) has failed in its sending. */
	360	void sctp_chunk_fail(struct sctp_chunk *chunk, int error)
	361	{
	362	chunk->msg->send_failed = 1;
	363	chunk->msg->send_error = error;
	364	}