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v3.15
  1/* SCTP kernel implementation
  2 * (C) Copyright IBM Corp. 2003, 2004
  3 *
  4 * This file is part of the SCTP kernel implementation
  5 *
  6 * This file contains the code relating the chunk abstraction.
  7 *
  8 * This SCTP implementation is free software;
  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 *
 14 * This SCTP implementation is distributed in the hope that it
 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, see
 22 * <http://www.gnu.org/licenses/>.
 23 *
 24 * Please send any bug reports or fixes you make to the
 25 * email address(es):
 26 *    lksctp developers <linux-sctp@vger.kernel.org>
 27 *
 28 * Written or modified by:
 29 *    Jon Grimm             <jgrimm@us.ibm.com>
 30 *    Sridhar Samudrala     <sri@us.ibm.com>
 31 */
 32
 33#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 34
 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>
 40#include <linux/slab.h>
 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. */
 50static 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;
 56	msg->can_delay = 1;
 57	msg->expires_at = 0;
 58	INIT_LIST_HEAD(&msg->chunks);
 59}
 60
 61/* Allocate and initialize datamsg. */
 62static struct sctp_datamsg *sctp_datamsg_new(gfp_t gfp)
 63{
 64	struct sctp_datamsg *msg;
 65	msg = kmalloc(sizeof(struct sctp_datamsg), gfp);
 66	if (msg) {
 67		sctp_datamsg_init(msg);
 68		SCTP_DBG_OBJCNT_INC(datamsg);
 69	}
 70	return msg;
 71}
 72
 73void 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
 86/* Final destructruction of datamsg memory. */
 87static 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. */
138static void sctp_datamsg_hold(struct sctp_datamsg *msg)
139{
140	atomic_inc(&msg->refcnt);
141}
142
143/* Release a reference. */
144void sctp_datamsg_put(struct sctp_datamsg *msg)
145{
146	if (atomic_dec_and_test(&msg->refcnt))
147		sctp_datamsg_destroy(msg);
148}
149
150/* Assign a chunk to this datamsg. */
151static 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 */
165struct 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;
171	int max_data;
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)
179		return ERR_PTR(-ENOMEM);
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;
189
190		pr_debug("%s: msg:%p expires_at:%ld jiffies:%ld\n", __func__,
191			 msg, msg->expires_at, jiffies);
192	}
193
194	/* This is the biggest possible DATA chunk that can fit into
195	 * the packet
196	 */
197	max_data = (asoc->pathmtu -
198		sctp_sk(asoc->base.sk)->pf->af->net_header_len -
199		sizeof(struct sctphdr) - sizeof(struct sctp_data_chunk)) & ~3;
200
201	max = asoc->frag_point;
202	/* If the the peer requested that we authenticate DATA chunks
203	 * we need to account for bundling of the AUTH chunks along with
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)
210			max_data -= WORD_ROUND(sizeof(sctp_auth_chunk_t) +
211					    hmac_desc->hmac_len);
212	}
213
214	/* Now, check if we need to reduce our max */
215	if (max > max_data)
216		max = max_data;
217
218	whole = 0;
219	first_len = max;
220
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
233	/* Encourage Cookie-ECHO bundling. */
234	if (asoc->state < SCTP_STATE_COOKIE_ECHOED)
235		max_data -= SCTP_ARBITRARY_COOKIE_ECHO_LEN;
236
237	/* Now that we adjusted completely, reset first_len */
238	if (first_len > max_data)
239		first_len = max_data;
240
241	/* Account for a different sized first fragment */
242	if (msg_len >= first_len) {
243		msg_len -= first_len;
244		whole = 1;
245		msg->can_delay = 0;
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))
254		SCTP_INC_STATS_USER(sock_net(asoc->base.sk), SCTP_MIB_FRAGUSRMSGS);
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
263		if ((i == (whole - 1)) && !over) {
264			frag |= SCTP_DATA_LAST_FRAG;
265
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
275		chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag, 0);
 
276
277		if (!chunk) {
278			err = -ENOMEM;
279			goto errout;
280		}
281
282		err = sctp_user_addto_chunk(chunk, offset, len, msgh->msg_iov);
283		if (err < 0)
284			goto errout_chunk_free;
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
309		if ((sinfo->sinfo_flags & SCTP_EOF) ||
310		    (sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
311			frag |= SCTP_DATA_SACK_IMM;
312
313		chunk = sctp_make_datafrag_empty(asoc, sinfo, over, frag, 0);
 
314
315		if (!chunk) {
316			err = -ENOMEM;
317			goto errout;
318		}
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)
326			goto errout_chunk_free;
327
328		sctp_datamsg_assign(msg, chunk);
329		list_add_tail(&chunk->frag_list, &msg->chunks);
330	}
331
332	return msg;
333
334errout_chunk_free:
335	sctp_chunk_free(chunk);
336
337errout:
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	}
343	sctp_datamsg_put(msg);
344	return ERR_PTR(err);
345}
346
347/* Check whether this message has expired. */
348int 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. */
362void sctp_chunk_fail(struct sctp_chunk *chunk, int error)
363{
364	chunk->msg->send_failed = 1;
365	chunk->msg->send_error = error;
366}
v4.6
  1/* SCTP kernel implementation
  2 * (C) Copyright IBM Corp. 2003, 2004
  3 *
  4 * This file is part of the SCTP kernel implementation
  5 *
  6 * This file contains the code relating the chunk abstraction.
  7 *
  8 * This SCTP implementation is free software;
  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 *
 14 * This SCTP implementation is distributed in the hope that it
 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, see
 22 * <http://www.gnu.org/licenses/>.
 23 *
 24 * Please send any bug reports or fixes you make to the
 25 * email address(es):
 26 *    lksctp developers <linux-sctp@vger.kernel.org>
 27 *
 28 * Written or modified by:
 29 *    Jon Grimm             <jgrimm@us.ibm.com>
 30 *    Sridhar Samudrala     <sri@us.ibm.com>
 31 */
 32
 33#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 34
 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>
 40#include <linux/slab.h>
 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. */
 50static 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;
 56	msg->can_delay = 1;
 57	msg->expires_at = 0;
 58	INIT_LIST_HEAD(&msg->chunks);
 59}
 60
 61/* Allocate and initialize datamsg. */
 62static struct sctp_datamsg *sctp_datamsg_new(gfp_t gfp)
 63{
 64	struct sctp_datamsg *msg;
 65	msg = kmalloc(sizeof(struct sctp_datamsg), gfp);
 66	if (msg) {
 67		sctp_datamsg_init(msg);
 68		SCTP_DBG_OBJCNT_INC(datamsg);
 69	}
 70	return msg;
 71}
 72
 
 
 
 
 
 
 
 
 
 
 
 
 
 73/* Final destructruction of datamsg memory. */
 74static void sctp_datamsg_destroy(struct sctp_datamsg *msg)
 75{
 76	struct list_head *pos, *temp;
 77	struct sctp_chunk *chunk;
 78	struct sctp_sock *sp;
 79	struct sctp_ulpevent *ev;
 80	struct sctp_association *asoc = NULL;
 81	int error = 0, notify;
 82
 83	/* If we failed, we may need to notify. */
 84	notify = msg->send_failed ? -1 : 0;
 85
 86	/* Release all references. */
 87	list_for_each_safe(pos, temp, &msg->chunks) {
 88		list_del_init(pos);
 89		chunk = list_entry(pos, struct sctp_chunk, frag_list);
 90		/* Check whether we _really_ need to notify. */
 91		if (notify < 0) {
 92			asoc = chunk->asoc;
 93			if (msg->send_error)
 94				error = msg->send_error;
 95			else
 96				error = asoc->outqueue.error;
 97
 98			sp = sctp_sk(asoc->base.sk);
 99			notify = sctp_ulpevent_type_enabled(SCTP_SEND_FAILED,
100							    &sp->subscribe);
101		}
102
103		/* Generate a SEND FAILED event only if enabled. */
104		if (notify > 0) {
105			int sent;
106			if (chunk->has_tsn)
107				sent = SCTP_DATA_SENT;
108			else
109				sent = SCTP_DATA_UNSENT;
110
111			ev = sctp_ulpevent_make_send_failed(asoc, chunk, sent,
112							    error, GFP_ATOMIC);
113			if (ev)
114				sctp_ulpq_tail_event(&asoc->ulpq, ev);
115		}
116
117		sctp_chunk_put(chunk);
118	}
119
120	SCTP_DBG_OBJCNT_DEC(datamsg);
121	kfree(msg);
122}
123
124/* Hold a reference. */
125static void sctp_datamsg_hold(struct sctp_datamsg *msg)
126{
127	atomic_inc(&msg->refcnt);
128}
129
130/* Release a reference. */
131void sctp_datamsg_put(struct sctp_datamsg *msg)
132{
133	if (atomic_dec_and_test(&msg->refcnt))
134		sctp_datamsg_destroy(msg);
135}
136
137/* Assign a chunk to this datamsg. */
138static void sctp_datamsg_assign(struct sctp_datamsg *msg, struct sctp_chunk *chunk)
139{
140	sctp_datamsg_hold(msg);
141	chunk->msg = msg;
142}
143
144
145/* A data chunk can have a maximum payload of (2^16 - 20).  Break
146 * down any such message into smaller chunks.  Opportunistically, fragment
147 * the chunks down to the current MTU constraints.  We may get refragmented
148 * later if the PMTU changes, but it is _much better_ to fragment immediately
149 * with a reasonable guess than always doing our fragmentation on the
150 * soft-interrupt.
151 */
152struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
153					    struct sctp_sndrcvinfo *sinfo,
154					    struct iov_iter *from)
155{
156	int max, whole, i, offset, over, err;
157	int len, first_len;
158	int max_data;
159	struct sctp_chunk *chunk;
160	struct sctp_datamsg *msg;
161	struct list_head *pos, *temp;
162	size_t msg_len = iov_iter_count(from);
163	__u8 frag;
164
165	msg = sctp_datamsg_new(GFP_KERNEL);
166	if (!msg)
167		return ERR_PTR(-ENOMEM);
168
169	/* Note: Calculate this outside of the loop, so that all fragments
170	 * have the same expiration.
171	 */
172	if (sinfo->sinfo_timetolive) {
173		/* sinfo_timetolive is in milliseconds */
174		msg->expires_at = jiffies +
175				    msecs_to_jiffies(sinfo->sinfo_timetolive);
176		msg->can_abandon = 1;
177
178		pr_debug("%s: msg:%p expires_at:%ld jiffies:%ld\n", __func__,
179			 msg, msg->expires_at, jiffies);
180	}
181
182	/* This is the biggest possible DATA chunk that can fit into
183	 * the packet
184	 */
185	max_data = (asoc->pathmtu -
186		sctp_sk(asoc->base.sk)->pf->af->net_header_len -
187		sizeof(struct sctphdr) - sizeof(struct sctp_data_chunk)) & ~3;
188
189	max = asoc->frag_point;
190	/* If the the peer requested that we authenticate DATA chunks
191	 * we need to account for bundling of the AUTH chunks along with
192	 * DATA.
193	 */
194	if (sctp_auth_send_cid(SCTP_CID_DATA, asoc)) {
195		struct sctp_hmac *hmac_desc = sctp_auth_asoc_get_hmac(asoc);
196
197		if (hmac_desc)
198			max_data -= WORD_ROUND(sizeof(sctp_auth_chunk_t) +
199					    hmac_desc->hmac_len);
200	}
201
202	/* Now, check if we need to reduce our max */
203	if (max > max_data)
204		max = max_data;
205
206	whole = 0;
207	first_len = max;
208
209	/* Check to see if we have a pending SACK and try to let it be bundled
210	 * with this message.  Do this if we don't have any data queued already.
211	 * To check that, look at out_qlen and retransmit list.
212	 * NOTE: we will not reduce to account for SACK, if the message would
213	 * not have been fragmented.
214	 */
215	if (timer_pending(&asoc->timers[SCTP_EVENT_TIMEOUT_SACK]) &&
216	    asoc->outqueue.out_qlen == 0 &&
217	    list_empty(&asoc->outqueue.retransmit) &&
218	    msg_len > max)
219		max_data -= WORD_ROUND(sizeof(sctp_sack_chunk_t));
220
221	/* Encourage Cookie-ECHO bundling. */
222	if (asoc->state < SCTP_STATE_COOKIE_ECHOED)
223		max_data -= SCTP_ARBITRARY_COOKIE_ECHO_LEN;
224
225	/* Now that we adjusted completely, reset first_len */
226	if (first_len > max_data)
227		first_len = max_data;
228
229	/* Account for a different sized first fragment */
230	if (msg_len >= first_len) {
231		msg_len -= first_len;
232		whole = 1;
233		msg->can_delay = 0;
234	}
235
236	/* How many full sized?  How many bytes leftover? */
237	whole += msg_len / max;
238	over = msg_len % max;
239	offset = 0;
240
241	if ((whole > 1) || (whole && over))
242		SCTP_INC_STATS_USER(sock_net(asoc->base.sk), SCTP_MIB_FRAGUSRMSGS);
243
244	/* Create chunks for all the full sized DATA chunks. */
245	for (i = 0, len = first_len; i < whole; i++) {
246		frag = SCTP_DATA_MIDDLE_FRAG;
247
248		if (0 == i)
249			frag |= SCTP_DATA_FIRST_FRAG;
250
251		if ((i == (whole - 1)) && !over) {
252			frag |= SCTP_DATA_LAST_FRAG;
253
254			/* The application requests to set the I-bit of the
255			 * last DATA chunk of a user message when providing
256			 * the user message to the SCTP implementation.
257			 */
258			if ((sinfo->sinfo_flags & SCTP_EOF) ||
259			    (sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
260				frag |= SCTP_DATA_SACK_IMM;
261		}
262
263		chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag,
264						 0, GFP_KERNEL);
265
266		if (!chunk) {
267			err = -ENOMEM;
268			goto errout;
269		}
270
271		err = sctp_user_addto_chunk(chunk, len, from);
272		if (err < 0)
273			goto errout_chunk_free;
274
 
 
275		/* Put the chunk->skb back into the form expected by send.  */
276		__skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
277			   - (__u8 *)chunk->skb->data);
278
279		sctp_datamsg_assign(msg, chunk);
280		list_add_tail(&chunk->frag_list, &msg->chunks);
281
282		/* The first chunk, the first chunk was likely short
283		 * to allow bundling, so reset to full size.
284		 */
285		if (0 == i)
286			len = max;
287	}
288
289	/* .. now the leftover bytes. */
290	if (over) {
291		if (!whole)
292			frag = SCTP_DATA_NOT_FRAG;
293		else
294			frag = SCTP_DATA_LAST_FRAG;
295
296		if ((sinfo->sinfo_flags & SCTP_EOF) ||
297		    (sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
298			frag |= SCTP_DATA_SACK_IMM;
299
300		chunk = sctp_make_datafrag_empty(asoc, sinfo, over, frag,
301						 0, GFP_KERNEL);
302
303		if (!chunk) {
304			err = -ENOMEM;
305			goto errout;
306		}
307
308		err = sctp_user_addto_chunk(chunk, over, from);
309
310		/* Put the chunk->skb back into the form expected by send.  */
311		__skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
312			   - (__u8 *)chunk->skb->data);
313		if (err < 0)
314			goto errout_chunk_free;
315
316		sctp_datamsg_assign(msg, chunk);
317		list_add_tail(&chunk->frag_list, &msg->chunks);
318	}
319
320	return msg;
321
322errout_chunk_free:
323	sctp_chunk_free(chunk);
324
325errout:
326	list_for_each_safe(pos, temp, &msg->chunks) {
327		list_del_init(pos);
328		chunk = list_entry(pos, struct sctp_chunk, frag_list);
329		sctp_chunk_free(chunk);
330	}
331	sctp_datamsg_put(msg);
332	return ERR_PTR(err);
333}
334
335/* Check whether this message has expired. */
336int sctp_chunk_abandoned(struct sctp_chunk *chunk)
337{
338	struct sctp_datamsg *msg = chunk->msg;
339
340	if (!msg->can_abandon)
341		return 0;
342
343	if (time_after(jiffies, msg->expires_at))
344		return 1;
345
346	return 0;
347}
348
349/* This chunk (and consequently entire message) has failed in its sending. */
350void sctp_chunk_fail(struct sctp_chunk *chunk, int error)
351{
352	chunk->msg->send_failed = 1;
353	chunk->msg->send_error = error;
354}