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v6.2
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/* SCTP kernel implementation
  3 * (C) Copyright IBM Corp. 2003, 2004
  4 *
  5 * This file is part of the SCTP kernel implementation
  6 *
  7 * This file contains the code relating the chunk abstraction.
  8 *
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  9 * Please send any bug reports or fixes you make to the
 10 * email address(es):
 11 *    lksctp developers <linux-sctp@vger.kernel.org>
 12 *
 13 * Written or modified by:
 14 *    Jon Grimm             <jgrimm@us.ibm.com>
 15 *    Sridhar Samudrala     <sri@us.ibm.com>
 16 */
 17
 18#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 19
 20#include <linux/types.h>
 21#include <linux/kernel.h>
 22#include <linux/net.h>
 23#include <linux/inet.h>
 24#include <linux/skbuff.h>
 25#include <linux/slab.h>
 26#include <net/sock.h>
 27#include <net/sctp/sctp.h>
 28#include <net/sctp/sm.h>
 29
 30/* This file is mostly in anticipation of future work, but initially
 31 * populate with fragment tracking for an outbound message.
 32 */
 33
 34/* Initialize datamsg from memory. */
 35static void sctp_datamsg_init(struct sctp_datamsg *msg)
 36{
 37	refcount_set(&msg->refcnt, 1);
 38	msg->send_failed = 0;
 39	msg->send_error = 0;
 40	msg->can_delay = 1;
 41	msg->abandoned = 0;
 42	msg->expires_at = 0;
 43	INIT_LIST_HEAD(&msg->chunks);
 44}
 45
 46/* Allocate and initialize datamsg. */
 47static struct sctp_datamsg *sctp_datamsg_new(gfp_t gfp)
 48{
 49	struct sctp_datamsg *msg;
 50	msg = kmalloc(sizeof(struct sctp_datamsg), gfp);
 51	if (msg) {
 52		sctp_datamsg_init(msg);
 53		SCTP_DBG_OBJCNT_INC(datamsg);
 54	}
 55	return msg;
 56}
 57
 58void sctp_datamsg_free(struct sctp_datamsg *msg)
 59{
 60	struct sctp_chunk *chunk;
 61
 62	/* This doesn't have to be a _safe vairant because
 63	 * sctp_chunk_free() only drops the refs.
 64	 */
 65	list_for_each_entry(chunk, &msg->chunks, frag_list)
 66		sctp_chunk_free(chunk);
 67
 68	sctp_datamsg_put(msg);
 69}
 70
 71/* Final destructruction of datamsg memory. */
 72static void sctp_datamsg_destroy(struct sctp_datamsg *msg)
 73{
 74	struct sctp_association *asoc = NULL;
 75	struct list_head *pos, *temp;
 76	struct sctp_chunk *chunk;
 
 77	struct sctp_ulpevent *ev;
 78	int error, sent;
 
 
 
 
 79
 80	/* Release all references. */
 81	list_for_each_safe(pos, temp, &msg->chunks) {
 82		list_del_init(pos);
 83		chunk = list_entry(pos, struct sctp_chunk, frag_list);
 84
 85		if (!msg->send_failed) {
 86			sctp_chunk_put(chunk);
 87			continue;
 
 
 
 
 
 
 
 88		}
 89
 90		asoc = chunk->asoc;
 91		error = msg->send_error ?: asoc->outqueue.error;
 92		sent = chunk->has_tsn ? SCTP_DATA_SENT : SCTP_DATA_UNSENT;
 
 
 
 
 93
 94		if (sctp_ulpevent_type_enabled(asoc->subscribe,
 95					       SCTP_SEND_FAILED)) {
 96			ev = sctp_ulpevent_make_send_failed(asoc, chunk, sent,
 97							    error, GFP_ATOMIC);
 98			if (ev)
 99				asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
100		}
101
102		if (sctp_ulpevent_type_enabled(asoc->subscribe,
103					       SCTP_SEND_FAILED_EVENT)) {
104			ev = sctp_ulpevent_make_send_failed_event(asoc, chunk,
105								  sent, error,
106								  GFP_ATOMIC);
107			if (ev)
108				asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
109		}
110
111		sctp_chunk_put(chunk);
112	}
113
114	SCTP_DBG_OBJCNT_DEC(datamsg);
115	kfree(msg);
116}
117
118/* Hold a reference. */
119static void sctp_datamsg_hold(struct sctp_datamsg *msg)
120{
121	refcount_inc(&msg->refcnt);
122}
123
124/* Release a reference. */
125void sctp_datamsg_put(struct sctp_datamsg *msg)
126{
127	if (refcount_dec_and_test(&msg->refcnt))
128		sctp_datamsg_destroy(msg);
129}
130
131/* Assign a chunk to this datamsg. */
132static void sctp_datamsg_assign(struct sctp_datamsg *msg, struct sctp_chunk *chunk)
133{
134	sctp_datamsg_hold(msg);
135	chunk->msg = msg;
136}
137
138
139/* A data chunk can have a maximum payload of (2^16 - 20).  Break
140 * down any such message into smaller chunks.  Opportunistically, fragment
141 * the chunks down to the current MTU constraints.  We may get refragmented
142 * later if the PMTU changes, but it is _much better_ to fragment immediately
143 * with a reasonable guess than always doing our fragmentation on the
144 * soft-interrupt.
145 */
146struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
147					    struct sctp_sndrcvinfo *sinfo,
148					    struct iov_iter *from)
149{
150	size_t len, first_len, max_data, remaining;
151	size_t msg_len = iov_iter_count(from);
152	struct sctp_shared_key *shkey = NULL;
153	struct list_head *pos, *temp;
154	struct sctp_chunk *chunk;
155	struct sctp_datamsg *msg;
 
 
156	int err;
157
158	msg = sctp_datamsg_new(GFP_KERNEL);
159	if (!msg)
160		return ERR_PTR(-ENOMEM);
161
162	/* Note: Calculate this outside of the loop, so that all fragments
163	 * have the same expiration.
164	 */
165	if (asoc->peer.prsctp_capable && sinfo->sinfo_timetolive &&
166	    (SCTP_PR_TTL_ENABLED(sinfo->sinfo_flags) ||
167	     !SCTP_PR_POLICY(sinfo->sinfo_flags)))
168		msg->expires_at = jiffies +
169				  msecs_to_jiffies(sinfo->sinfo_timetolive);
170
171	/* This is the biggest possible DATA chunk that can fit into
172	 * the packet
173	 */
174	max_data = asoc->frag_point;
175	if (unlikely(!max_data)) {
176		max_data = sctp_min_frag_point(sctp_sk(asoc->base.sk),
177					       sctp_datachk_len(&asoc->stream));
178		pr_warn_ratelimited("%s: asoc:%p frag_point is zero, forcing max_data to default minimum (%zu)",
179				    __func__, asoc, max_data);
180	}
181
182	/* If the peer requested that we authenticate DATA chunks
183	 * we need to account for bundling of the AUTH chunks along with
184	 * DATA.
185	 */
186	if (sctp_auth_send_cid(SCTP_CID_DATA, asoc)) {
187		struct sctp_hmac *hmac_desc = sctp_auth_asoc_get_hmac(asoc);
188
189		if (hmac_desc)
190			max_data -= SCTP_PAD4(sizeof(struct sctp_auth_chunk) +
191					      hmac_desc->hmac_len);
192
193		if (sinfo->sinfo_tsn &&
194		    sinfo->sinfo_ssn != asoc->active_key_id) {
195			shkey = sctp_auth_get_shkey(asoc, sinfo->sinfo_ssn);
196			if (!shkey) {
197				err = -EINVAL;
198				goto errout;
199			}
200		} else {
201			shkey = asoc->shkey;
202		}
203	}
204
 
 
 
205	/* Set first_len and then account for possible bundles on first frag */
206	first_len = max_data;
207
208	/* Check to see if we have a pending SACK and try to let it be bundled
209	 * with this message.  Do this if we don't have any data queued already.
210	 * To check that, look at out_qlen and retransmit list.
211	 * NOTE: we will not reduce to account for SACK, if the message would
212	 * not have been fragmented.
213	 */
214	if (timer_pending(&asoc->timers[SCTP_EVENT_TIMEOUT_SACK]) &&
215	    asoc->outqueue.out_qlen == 0 &&
216	    list_empty(&asoc->outqueue.retransmit) &&
217	    msg_len > max_data)
218		first_len -= SCTP_PAD4(sizeof(struct sctp_sack_chunk));
219
220	/* Encourage Cookie-ECHO bundling. */
221	if (asoc->state < SCTP_STATE_COOKIE_ECHOED)
222		first_len -= SCTP_ARBITRARY_COOKIE_ECHO_LEN;
223
224	/* Account for a different sized first fragment */
225	if (msg_len >= first_len) {
226		msg->can_delay = 0;
227		if (msg_len > first_len)
228			SCTP_INC_STATS(asoc->base.net,
229				       SCTP_MIB_FRAGUSRMSGS);
230	} else {
231		/* Which may be the only one... */
232		first_len = msg_len;
233	}
234
235	/* Create chunks for all DATA chunks. */
236	for (remaining = msg_len; remaining; remaining -= len) {
237		u8 frag = SCTP_DATA_MIDDLE_FRAG;
238
239		if (remaining == msg_len) {
240			/* First frag, which may also be the last */
241			frag |= SCTP_DATA_FIRST_FRAG;
242			len = first_len;
243		} else {
244			/* Middle frags */
245			len = max_data;
246		}
247
248		if (len >= remaining) {
249			/* Last frag, which may also be the first */
250			len = remaining;
251			frag |= SCTP_DATA_LAST_FRAG;
252
253			/* The application requests to set the I-bit of the
254			 * last DATA chunk of a user message when providing
255			 * the user message to the SCTP implementation.
256			 */
257			if ((sinfo->sinfo_flags & SCTP_EOF) ||
258			    (sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
259				frag |= SCTP_DATA_SACK_IMM;
260		}
261
262		chunk = asoc->stream.si->make_datafrag(asoc, sinfo, len, frag,
263						       GFP_KERNEL);
264		if (!chunk) {
265			err = -ENOMEM;
266			goto errout;
267		}
268
269		err = sctp_user_addto_chunk(chunk, len, from);
270		if (err < 0)
271			goto errout_chunk_free;
272
273		chunk->shkey = shkey;
274
275		/* Put the chunk->skb back into the form expected by send.  */
276		__skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr -
277				       chunk->skb->data);
278
279		sctp_datamsg_assign(msg, chunk);
280		list_add_tail(&chunk->frag_list, &msg->chunks);
281	}
282
283	return msg;
284
285errout_chunk_free:
286	sctp_chunk_free(chunk);
287
288errout:
289	list_for_each_safe(pos, temp, &msg->chunks) {
290		list_del_init(pos);
291		chunk = list_entry(pos, struct sctp_chunk, frag_list);
292		sctp_chunk_free(chunk);
293	}
294	sctp_datamsg_put(msg);
295
296	return ERR_PTR(err);
297}
298
299/* Check whether this message has expired. */
300int sctp_chunk_abandoned(struct sctp_chunk *chunk)
301{
302	if (!chunk->asoc->peer.prsctp_capable)
303		return 0;
304
305	if (chunk->msg->abandoned)
306		return 1;
307
308	if (!chunk->has_tsn &&
309	    !(chunk->chunk_hdr->flags & SCTP_DATA_FIRST_FRAG))
310		return 0;
311
312	if (SCTP_PR_TTL_ENABLED(chunk->sinfo.sinfo_flags) &&
313	    time_after(jiffies, chunk->msg->expires_at)) {
314		struct sctp_stream_out *streamout =
315			SCTP_SO(&chunk->asoc->stream,
316				chunk->sinfo.sinfo_stream);
317
318		if (chunk->sent_count) {
319			chunk->asoc->abandoned_sent[SCTP_PR_INDEX(TTL)]++;
320			streamout->ext->abandoned_sent[SCTP_PR_INDEX(TTL)]++;
321		} else {
322			chunk->asoc->abandoned_unsent[SCTP_PR_INDEX(TTL)]++;
323			streamout->ext->abandoned_unsent[SCTP_PR_INDEX(TTL)]++;
324		}
325		chunk->msg->abandoned = 1;
326		return 1;
327	} else if (SCTP_PR_RTX_ENABLED(chunk->sinfo.sinfo_flags) &&
328		   chunk->sent_count > chunk->sinfo.sinfo_timetolive) {
329		struct sctp_stream_out *streamout =
330			SCTP_SO(&chunk->asoc->stream,
331				chunk->sinfo.sinfo_stream);
332
333		chunk->asoc->abandoned_sent[SCTP_PR_INDEX(RTX)]++;
334		streamout->ext->abandoned_sent[SCTP_PR_INDEX(RTX)]++;
335		chunk->msg->abandoned = 1;
336		return 1;
337	} else if (!SCTP_PR_POLICY(chunk->sinfo.sinfo_flags) &&
338		   chunk->msg->expires_at &&
339		   time_after(jiffies, chunk->msg->expires_at)) {
340		chunk->msg->abandoned = 1;
341		return 1;
342	}
343	/* PRIO policy is processed by sendmsg, not here */
344
345	return 0;
346}
347
348/* This chunk (and consequently entire message) has failed in its sending. */
349void sctp_chunk_fail(struct sctp_chunk *chunk, int error)
350{
351	chunk->msg->send_failed = 1;
352	chunk->msg->send_error = error;
353}
v4.17
 
  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	refcount_set(&msg->refcnt, 1);
 53	msg->send_failed = 0;
 54	msg->send_error = 0;
 55	msg->can_delay = 1;
 56	msg->abandoned = 0;
 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				asoc->stream.si->enqueue_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	refcount_inc(&msg->refcnt);
141}
142
143/* Release a reference. */
144void sctp_datamsg_put(struct sctp_datamsg *msg)
145{
146	if (refcount_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 iov_iter *from)
168{
169	size_t len, first_len, max_data, remaining;
170	size_t msg_len = iov_iter_count(from);
171	struct sctp_shared_key *shkey = NULL;
172	struct list_head *pos, *temp;
173	struct sctp_chunk *chunk;
174	struct sctp_datamsg *msg;
175	struct sctp_sock *sp;
176	struct sctp_af *af;
177	int err;
178
179	msg = sctp_datamsg_new(GFP_KERNEL);
180	if (!msg)
181		return ERR_PTR(-ENOMEM);
182
183	/* Note: Calculate this outside of the loop, so that all fragments
184	 * have the same expiration.
185	 */
186	if (asoc->peer.prsctp_capable && sinfo->sinfo_timetolive &&
187	    (SCTP_PR_TTL_ENABLED(sinfo->sinfo_flags) ||
188	     !SCTP_PR_POLICY(sinfo->sinfo_flags)))
189		msg->expires_at = jiffies +
190				  msecs_to_jiffies(sinfo->sinfo_timetolive);
191
192	/* This is the biggest possible DATA chunk that can fit into
193	 * the packet
194	 */
195	sp = sctp_sk(asoc->base.sk);
196	af = sp->pf->af;
197	max_data = asoc->pathmtu - af->net_header_len -
198		   sizeof(struct sctphdr) - sctp_datachk_len(&asoc->stream) -
199		   af->ip_options_len(asoc->base.sk);
200	max_data = SCTP_TRUNC4(max_data);
 
201
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 -= SCTP_PAD4(sizeof(struct sctp_auth_chunk) +
211					      hmac_desc->hmac_len);
212
213		if (sinfo->sinfo_tsn &&
214		    sinfo->sinfo_ssn != asoc->active_key_id) {
215			shkey = sctp_auth_get_shkey(asoc, sinfo->sinfo_ssn);
216			if (!shkey) {
217				err = -EINVAL;
218				goto errout;
219			}
220		} else {
221			shkey = asoc->shkey;
222		}
223	}
224
225	/* Check what's our max considering the above */
226	max_data = min_t(size_t, max_data, asoc->frag_point);
227
228	/* Set first_len and then account for possible bundles on first frag */
229	first_len = max_data;
230
231	/* Check to see if we have a pending SACK and try to let it be bundled
232	 * with this message.  Do this if we don't have any data queued already.
233	 * To check that, look at out_qlen and retransmit list.
234	 * NOTE: we will not reduce to account for SACK, if the message would
235	 * not have been fragmented.
236	 */
237	if (timer_pending(&asoc->timers[SCTP_EVENT_TIMEOUT_SACK]) &&
238	    asoc->outqueue.out_qlen == 0 &&
239	    list_empty(&asoc->outqueue.retransmit) &&
240	    msg_len > max_data)
241		first_len -= SCTP_PAD4(sizeof(struct sctp_sack_chunk));
242
243	/* Encourage Cookie-ECHO bundling. */
244	if (asoc->state < SCTP_STATE_COOKIE_ECHOED)
245		first_len -= SCTP_ARBITRARY_COOKIE_ECHO_LEN;
246
247	/* Account for a different sized first fragment */
248	if (msg_len >= first_len) {
249		msg->can_delay = 0;
250		SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_FRAGUSRMSGS);
 
 
251	} else {
252		/* Which may be the only one... */
253		first_len = msg_len;
254	}
255
256	/* Create chunks for all DATA chunks. */
257	for (remaining = msg_len; remaining; remaining -= len) {
258		u8 frag = SCTP_DATA_MIDDLE_FRAG;
259
260		if (remaining == msg_len) {
261			/* First frag, which may also be the last */
262			frag |= SCTP_DATA_FIRST_FRAG;
263			len = first_len;
264		} else {
265			/* Middle frags */
266			len = max_data;
267		}
268
269		if (len >= remaining) {
270			/* Last frag, which may also be the first */
271			len = remaining;
272			frag |= SCTP_DATA_LAST_FRAG;
273
274			/* The application requests to set the I-bit of the
275			 * last DATA chunk of a user message when providing
276			 * the user message to the SCTP implementation.
277			 */
278			if ((sinfo->sinfo_flags & SCTP_EOF) ||
279			    (sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
280				frag |= SCTP_DATA_SACK_IMM;
281		}
282
283		chunk = asoc->stream.si->make_datafrag(asoc, sinfo, len, frag,
284						       GFP_KERNEL);
285		if (!chunk) {
286			err = -ENOMEM;
287			goto errout;
288		}
289
290		err = sctp_user_addto_chunk(chunk, len, from);
291		if (err < 0)
292			goto errout_chunk_free;
293
294		chunk->shkey = shkey;
295
296		/* Put the chunk->skb back into the form expected by send.  */
297		__skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr -
298				       chunk->skb->data);
299
300		sctp_datamsg_assign(msg, chunk);
301		list_add_tail(&chunk->frag_list, &msg->chunks);
302	}
303
304	return msg;
305
306errout_chunk_free:
307	sctp_chunk_free(chunk);
308
309errout:
310	list_for_each_safe(pos, temp, &msg->chunks) {
311		list_del_init(pos);
312		chunk = list_entry(pos, struct sctp_chunk, frag_list);
313		sctp_chunk_free(chunk);
314	}
315	sctp_datamsg_put(msg);
316
317	return ERR_PTR(err);
318}
319
320/* Check whether this message has expired. */
321int sctp_chunk_abandoned(struct sctp_chunk *chunk)
322{
323	if (!chunk->asoc->peer.prsctp_capable)
324		return 0;
325
326	if (chunk->msg->abandoned)
327		return 1;
328
329	if (!chunk->has_tsn &&
330	    !(chunk->chunk_hdr->flags & SCTP_DATA_FIRST_FRAG))
331		return 0;
332
333	if (SCTP_PR_TTL_ENABLED(chunk->sinfo.sinfo_flags) &&
334	    time_after(jiffies, chunk->msg->expires_at)) {
335		struct sctp_stream_out *streamout =
336			&chunk->asoc->stream.out[chunk->sinfo.sinfo_stream];
 
337
338		if (chunk->sent_count) {
339			chunk->asoc->abandoned_sent[SCTP_PR_INDEX(TTL)]++;
340			streamout->ext->abandoned_sent[SCTP_PR_INDEX(TTL)]++;
341		} else {
342			chunk->asoc->abandoned_unsent[SCTP_PR_INDEX(TTL)]++;
343			streamout->ext->abandoned_unsent[SCTP_PR_INDEX(TTL)]++;
344		}
345		chunk->msg->abandoned = 1;
346		return 1;
347	} else if (SCTP_PR_RTX_ENABLED(chunk->sinfo.sinfo_flags) &&
348		   chunk->sent_count > chunk->sinfo.sinfo_timetolive) {
349		struct sctp_stream_out *streamout =
350			&chunk->asoc->stream.out[chunk->sinfo.sinfo_stream];
 
351
352		chunk->asoc->abandoned_sent[SCTP_PR_INDEX(RTX)]++;
353		streamout->ext->abandoned_sent[SCTP_PR_INDEX(RTX)]++;
354		chunk->msg->abandoned = 1;
355		return 1;
356	} else if (!SCTP_PR_POLICY(chunk->sinfo.sinfo_flags) &&
357		   chunk->msg->expires_at &&
358		   time_after(jiffies, chunk->msg->expires_at)) {
359		chunk->msg->abandoned = 1;
360		return 1;
361	}
362	/* PRIO policy is processed by sendmsg, not here */
363
364	return 0;
365}
366
367/* This chunk (and consequently entire message) has failed in its sending. */
368void sctp_chunk_fail(struct sctp_chunk *chunk, int error)
369{
370	chunk->msg->send_failed = 1;
371	chunk->msg->send_error = error;
372}