[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, see
 * <http://www.gnu.org/licenses/>.
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <[email protected]>
 *
 * Written or modified by:
 *    Jon Grimm             <[email protected]>
 *    Sridhar Samudrala     <[email protected]>
 */

#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 account 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
4b2f13a2 JK	21	* along with GNU CC; see the file COPYING. If not, see
4b2f13a2 JK	22	* <http://www.gnu.org/licenses/>.
1da177e4 LT	23	*
	24	* Please send any bug reports or fixes you make to the
	25	* email address(es):
91705c61	26	* lksctp developers <[email protected]>
1da177e4	27	*
1da177e4 LT	28	* Written or modified by:
	29	* Jon Grimm <[email protected]>
	30	* Sridhar Samudrala <[email protected]>
1da177e4 LT	31	*/
1da177e4 LT	32
145ce502 JP	33	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
145ce502 JP	34
1da177e4 LT	35	#include <linux/types.h>
	36	#include <linux/kernel.h>
	37	#include <linux/net.h>
	38	#include <linux/inet.h>
	39	#include <linux/skbuff.h>
5a0e3ad6	40	#include <linux/slab.h>
1da177e4 LT	41	#include <net/sock.h>
	42	#include <net/sctp/sctp.h>
	43	#include <net/sctp/sm.h>
	44
	45	/* This file is mostly in anticipation of future work, but initially
	46	* populate with fragment tracking for an outbound message.
	47	*/
	48
	49	/* Initialize datamsg from memory. */
	50	static void sctp_datamsg_init(struct sctp_datamsg *msg)
	51	{
	52	atomic_set(&msg->refcnt, 1);
	53	msg->send_failed = 0;
	54	msg->send_error = 0;
	55	msg->can_abandon = 0;
0e3aef8d	56	msg->can_delay = 1;
1da177e4 LT	57	msg->expires_at = 0;
	58	INIT_LIST_HEAD(&msg->chunks);
	59	}
	60
	61	/* Allocate and initialize datamsg. */
dda91928	62	static struct sctp_datamsg *sctp_datamsg_new(gfp_t gfp)
1da177e4 LT	63	{
	64	struct sctp_datamsg *msg;
	65	msg = kmalloc(sizeof(struct sctp_datamsg), gfp);
e8c38751	66	if (msg) {
1da177e4	67	sctp_datamsg_init(msg);
e8c38751 LZ	68	SCTP_DBG_OBJCNT_INC(datamsg);
e8c38751 LZ	69	}
1da177e4 LT	70	return msg;
	71	}
	72
9c5c62be VY	73	void sctp_datamsg_free(struct sctp_datamsg *msg)
	74	{
	75	struct sctp_chunk *chunk;
	76
	77	/* This doesn't have to be a _safe vairant because
	78	* sctp_chunk_free() only drops the refs.
	79	*/
	80	list_for_each_entry(chunk, &msg->chunks, frag_list)
	81	sctp_chunk_free(chunk);
	82
	83	sctp_datamsg_put(msg);
	84	}
	85
1da177e4 LT	86	/* Final destructruction of datamsg memory. */
	87	static void sctp_datamsg_destroy(struct sctp_datamsg *msg)
	88	{
	89	struct list_head pos, temp;
	90	struct sctp_chunk *chunk;
	91	struct sctp_sock *sp;
	92	struct sctp_ulpevent *ev;
	93	struct sctp_association *asoc = NULL;
	94	int error = 0, notify;
	95
	96	/* If we failed, we may need to notify. */
	97	notify = msg->send_failed ? -1 : 0;
	98
	99	/* Release all references. */
	100	list_for_each_safe(pos, temp, &msg->chunks) {
	101	list_del_init(pos);
	102	chunk = list_entry(pos, struct sctp_chunk, frag_list);
	103	/* Check whether we _really_ need to notify. */
	104	if (notify < 0) {
	105	asoc = chunk->asoc;
	106	if (msg->send_error)
	107	error = msg->send_error;
	108	else
	109	error = asoc->outqueue.error;
	110
	111	sp = sctp_sk(asoc->base.sk);
	112	notify = sctp_ulpevent_type_enabled(SCTP_SEND_FAILED,
	113	&sp->subscribe);
	114	}
	115
	116	/* Generate a SEND FAILED event only if enabled. */
	117	if (notify > 0) {
	118	int sent;
	119	if (chunk->has_tsn)
	120	sent = SCTP_DATA_SENT;
	121	else
	122	sent = SCTP_DATA_UNSENT;
	123
	124	ev = sctp_ulpevent_make_send_failed(asoc, chunk, sent,
	125	error, GFP_ATOMIC);
	126	if (ev)
	127	sctp_ulpq_tail_event(&asoc->ulpq, ev);
	128	}
	129
	130	sctp_chunk_put(chunk);
	131	}
	132
	133	SCTP_DBG_OBJCNT_DEC(datamsg);
	134	kfree(msg);
	135	}
	136
	137	/* Hold a reference. */
	138	static void sctp_datamsg_hold(struct sctp_datamsg *msg)
	139	{
	140	atomic_inc(&msg->refcnt);
	141	}
	142
	143	/* Release a reference. */
	144	void sctp_datamsg_put(struct sctp_datamsg *msg)
	145	{
	146	if (atomic_dec_and_test(&msg->refcnt))
	147	sctp_datamsg_destroy(msg);
	148	}
	149
1da177e4 LT	150	/* Assign a chunk to this datamsg. */
	151	static void sctp_datamsg_assign(struct sctp_datamsg msg, struct sctp_chunk chunk)
	152	{
	153	sctp_datamsg_hold(msg);
	154	chunk->msg = msg;
	155	}
	156
	157
	158	/* A data chunk can have a maximum payload of (2^16 - 20). Break
	159	* down any such message into smaller chunks. Opportunistically, fragment
	160	* the chunks down to the current MTU constraints. We may get refragmented
	161	* later if the PMTU changes, but it is _much better_ to fragment immediately
	162	* with a reasonable guess than always doing our fragmentation on the
	163	* soft-interrupt.
	164	*/
	165	struct sctp_datamsg sctp_datamsg_from_user(struct sctp_association asoc,
	166	struct sctp_sndrcvinfo *sinfo,
	167	struct msghdr *msgh, int msg_len)
	168	{
	169	int max, whole, i, offset, over, err;
	170	int len, first_len;
3e62abf9	171	int max_data;
1da177e4 LT	172	struct sctp_chunk *chunk;
	173	struct sctp_datamsg *msg;
	174	struct list_head pos, temp;
	175	__u8 frag;
	176
	177	msg = sctp_datamsg_new(GFP_KERNEL);
	178	if (!msg)
6e51fe75	179	return ERR_PTR(-ENOMEM);
1da177e4 LT	180
	181	/* Note: Calculate this outside of the loop, so that all fragments
	182	* have the same expiration.
	183	*/
	184	if (sinfo->sinfo_timetolive) {
	185	/* sinfo_timetolive is in milliseconds */
	186	msg->expires_at = jiffies +
	187	msecs_to_jiffies(sinfo->sinfo_timetolive);
	188	msg->can_abandon = 1;
bb33381d DB	189
	190	pr_debug("%s: msg:%p expires_at:%ld jiffies:%ld\n", __func__,
	191	msg, msg->expires_at, jiffies);
1da177e4 LT	192	}
1da177e4 LT	193
3e62abf9 VY	194	/* This is the biggest possible DATA chunk that can fit into
	195	* the packet
	196	*/
c08751c8	197	max_data = (asoc->pathmtu -
3e62abf9	198	sctp_sk(asoc->base.sk)->pf->af->net_header_len -
c08751c8	199	sizeof(struct sctphdr) - sizeof(struct sctp_data_chunk)) & ~3;
1da177e4	200
3e62abf9	201	max = asoc->frag_point;
4cd57c80	202	/* If the the peer requested that we authenticate DATA chunks
2bccbadf	203	* we need to account for bundling of the AUTH chunks along with
4cd57c80 VY	204	* DATA.
	205	*/
	206	if (sctp_auth_send_cid(SCTP_CID_DATA, asoc)) {
	207	struct sctp_hmac *hmac_desc = sctp_auth_asoc_get_hmac(asoc);
	208
	209	if (hmac_desc)
3e62abf9	210	max_data -= WORD_ROUND(sizeof(sctp_auth_chunk_t) +
4cd57c80 VY	211	hmac_desc->hmac_len);
	212	}
	213
3e62abf9 VY	214	/* Now, check if we need to reduce our max */
	215	if (max > max_data)
	216	max = max_data;
	217
1da177e4 LT	218	whole = 0;
	219	first_len = max;
	220
5d7ff261 VY	221	/* Check to see if we have a pending SACK and try to let it be bundled
	222	* with this message. Do this if we don't have any data queued already.
	223	* To check that, look at out_qlen and retransmit list.
	224	* NOTE: we will not reduce to account for SACK, if the message would
	225	* not have been fragmented.
	226	*/
	227	if (timer_pending(&asoc->timers[SCTP_EVENT_TIMEOUT_SACK]) &&
	228	asoc->outqueue.out_qlen == 0 &&
	229	list_empty(&asoc->outqueue.retransmit) &&
	230	msg_len > max)
	231	max_data -= WORD_ROUND(sizeof(sctp_sack_chunk_t));
	232
1da177e4	233	/* Encourage Cookie-ECHO bundling. */
5d7ff261	234	if (asoc->state < SCTP_STATE_COOKIE_ECHOED)
3e62abf9	235	max_data -= SCTP_ARBITRARY_COOKIE_ECHO_LEN;
1da177e4	236
5d7ff261 VY	237	/* Now that we adjusted completely, reset first_len */
	238	if (first_len > max_data)
	239	first_len = max_data;
3e62abf9 VY	240
	241	/* Account for a different sized first fragment */
	242	if (msg_len >= first_len) {
	243	msg_len -= first_len;
	244	whole = 1;
0e3aef8d	245	msg->can_delay = 0;
1da177e4 LT	246	}
	247
	248	/* How many full sized? How many bytes leftover? */
	249	whole += msg_len / max;
	250	over = msg_len % max;
	251	offset = 0;
	252
	253	if ((whole > 1) \|\| (whole && over))
b01a2407	254	SCTP_INC_STATS_USER(sock_net(asoc->base.sk), SCTP_MIB_FRAGUSRMSGS);
1da177e4 LT	255
	256	/* Create chunks for all the full sized DATA chunks. */
	257	for (i=0, len=first_len; i < whole; i++) {
	258	frag = SCTP_DATA_MIDDLE_FRAG;
	259
	260	if (0 == i)
	261	frag \|= SCTP_DATA_FIRST_FRAG;
	262
b93d6471	263	if ((i == (whole - 1)) && !over) {
1da177e4 LT	264	frag \|= SCTP_DATA_LAST_FRAG;
1da177e4 LT	265
b93d6471 WY	266	/* The application requests to set the I-bit of the
	267	* last DATA chunk of a user message when providing
	268	* the user message to the SCTP implementation.
	269	*/
	270	if ((sinfo->sinfo_flags & SCTP_EOF) \|\|
	271	(sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
	272	frag \|= SCTP_DATA_SACK_IMM;
	273	}
	274
1da177e4 LT	275	chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag, 0);
1da177e4 LT	276
6e51fe75 TR	277	if (!chunk) {
6e51fe75 TR	278	err = -ENOMEM;
1da177e4	279	goto errout;
6e51fe75 TR	280	}
6e51fe75 TR	281
1da177e4 LT	282	err = sctp_user_addto_chunk(chunk, offset, len, msgh->msg_iov);
1da177e4 LT	283	if (err < 0)
be364c8c	284	goto errout_chunk_free;
1da177e4 LT	285
	286	offset += len;
	287
	288	/* Put the chunk->skb back into the form expected by send. */
	289	__skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
	290	- (__u8 *)chunk->skb->data);
	291
	292	sctp_datamsg_assign(msg, chunk);
	293	list_add_tail(&chunk->frag_list, &msg->chunks);
	294
	295	/* The first chunk, the first chunk was likely short
	296	* to allow bundling, so reset to full size.
	297	*/
	298	if (0 == i)
	299	len = max;
	300	}
	301
	302	/* .. now the leftover bytes. */
	303	if (over) {
	304	if (!whole)
	305	frag = SCTP_DATA_NOT_FRAG;
	306	else
	307	frag = SCTP_DATA_LAST_FRAG;
	308
b93d6471 WY	309	if ((sinfo->sinfo_flags & SCTP_EOF) \|\|
	310	(sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
	311	frag \|= SCTP_DATA_SACK_IMM;
	312
1da177e4 LT	313	chunk = sctp_make_datafrag_empty(asoc, sinfo, over, frag, 0);
1da177e4 LT	314
6e51fe75 TR	315	if (!chunk) {
6e51fe75 TR	316	err = -ENOMEM;
1da177e4	317	goto errout;
6e51fe75	318	}
1da177e4 LT	319
	320	err = sctp_user_addto_chunk(chunk, offset, over,msgh->msg_iov);
	321
	322	/* Put the chunk->skb back into the form expected by send. */
	323	__skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
	324	- (__u8 *)chunk->skb->data);
	325	if (err < 0)
be364c8c	326	goto errout_chunk_free;
1da177e4 LT	327
	328	sctp_datamsg_assign(msg, chunk);
	329	list_add_tail(&chunk->frag_list, &msg->chunks);
	330	}
	331
	332	return msg;
	333
be364c8c TR	334	errout_chunk_free:
	335	sctp_chunk_free(chunk);
	336
1da177e4 LT	337	errout:
	338	list_for_each_safe(pos, temp, &msg->chunks) {
	339	list_del_init(pos);
	340	chunk = list_entry(pos, struct sctp_chunk, frag_list);
	341	sctp_chunk_free(chunk);
	342	}
80445cfb	343	sctp_datamsg_put(msg);
6e51fe75	344	return ERR_PTR(err);
1da177e4 LT	345	}
	346
	347	/* Check whether this message has expired. */
	348	int sctp_chunk_abandoned(struct sctp_chunk *chunk)
	349	{
	350	struct sctp_datamsg *msg = chunk->msg;
	351
	352	if (!msg->can_abandon)
	353	return 0;
	354
	355	if (time_after(jiffies, msg->expires_at))
	356	return 1;
	357
	358	return 0;
	359	}
	360
	361	/* This chunk (and consequently entire message) has failed in its sending. */
	362	void sctp_chunk_fail(struct sctp_chunk *chunk, int error)
	363	{
	364	chunk->msg->send_failed = 1;
	365	chunk->msg->send_error = error;
	366	}