Merge remote-tracking branches 'asoc/topic/max98373', 'asoc/topic/mtk', 'asoc/topic...
[linux-2.6-block.git] / net / sctp / chunk.c
CommitLineData
60c778b2 1/* SCTP kernel implementation
1da177e4
LT
2 * (C) Copyright IBM Corp. 2003, 2004
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
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 <linux-sctp@vger.kernel.org>
1da177e4 27 *
1da177e4
LT
28 * Written or modified by:
29 * Jon Grimm <jgrimm@us.ibm.com>
30 * Sridhar Samudrala <sri@us.ibm.com>
1da177e4
LT
31 */
32
145ce502
JP
33#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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. */
50static void sctp_datamsg_init(struct sctp_datamsg *msg)
51{
c0acdfb4 52 refcount_set(&msg->refcnt, 1);
1da177e4
LT
53 msg->send_failed = 0;
54 msg->send_error = 0;
0e3aef8d 55 msg->can_delay = 1;
e5f61296 56 msg->abandoned = 0;
1da177e4
LT
57 msg->expires_at = 0;
58 INIT_LIST_HEAD(&msg->chunks);
59}
60
61/* Allocate and initialize datamsg. */
dda91928 62static 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);
69 }
1da177e4
LT
70 return msg;
71}
72
b61c654f
XL
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
1da177e4
LT
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{
c0acdfb4 140 refcount_inc(&msg->refcnt);
1da177e4
LT
141}
142
143/* Release a reference. */
144void sctp_datamsg_put(struct sctp_datamsg *msg)
145{
c0acdfb4 146 if (refcount_dec_and_test(&msg->refcnt))
1da177e4
LT
147 sctp_datamsg_destroy(msg);
148}
149
1da177e4
LT
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,
e0eb093e 167 struct iov_iter *from)
1da177e4 168{
bfd2e4b8
MRL
169 size_t len, first_len, max_data, remaining;
170 size_t msg_len = iov_iter_count(from);
171 struct list_head *pos, *temp;
1da177e4
LT
172 struct sctp_chunk *chunk;
173 struct sctp_datamsg *msg;
bfd2e4b8 174 int err;
1da177e4
LT
175
176 msg = sctp_datamsg_new(GFP_KERNEL);
177 if (!msg)
6e51fe75 178 return ERR_PTR(-ENOMEM);
1da177e4
LT
179
180 /* Note: Calculate this outside of the loop, so that all fragments
181 * have the same expiration.
182 */
8ae808eb
XL
183 if (asoc->peer.prsctp_capable && sinfo->sinfo_timetolive &&
184 (SCTP_PR_TTL_ENABLED(sinfo->sinfo_flags) ||
185 !SCTP_PR_POLICY(sinfo->sinfo_flags)))
1da177e4 186 msg->expires_at = jiffies +
bfd2e4b8 187 msecs_to_jiffies(sinfo->sinfo_timetolive);
0605483f 188
3e62abf9
VY
189 /* This is the biggest possible DATA chunk that can fit into
190 * the packet
191 */
4a225ce3
MRL
192 max_data = asoc->pathmtu -
193 sctp_sk(asoc->base.sk)->pf->af->net_header_len -
194 sizeof(struct sctphdr) - sizeof(struct sctp_data_chunk);
195 max_data = SCTP_TRUNC4(max_data);
1da177e4 196
4cd57c80 197 /* If the the peer requested that we authenticate DATA chunks
2bccbadf 198 * we need to account for bundling of the AUTH chunks along with
4cd57c80
VY
199 * DATA.
200 */
201 if (sctp_auth_send_cid(SCTP_CID_DATA, asoc)) {
202 struct sctp_hmac *hmac_desc = sctp_auth_asoc_get_hmac(asoc);
203
204 if (hmac_desc)
bb96dec7 205 max_data -= SCTP_PAD4(sizeof(struct sctp_auth_chunk) +
e2f036a9 206 hmac_desc->hmac_len);
4cd57c80
VY
207 }
208
bfd2e4b8
MRL
209 /* Check what's our max considering the above */
210 max_data = min_t(size_t, max_data, asoc->frag_point);
3e62abf9 211
bfd2e4b8
MRL
212 /* Set first_len and then account for possible bundles on first frag */
213 first_len = max_data;
1da177e4 214
5d7ff261
VY
215 /* Check to see if we have a pending SACK and try to let it be bundled
216 * with this message. Do this if we don't have any data queued already.
217 * To check that, look at out_qlen and retransmit list.
218 * NOTE: we will not reduce to account for SACK, if the message would
219 * not have been fragmented.
220 */
221 if (timer_pending(&asoc->timers[SCTP_EVENT_TIMEOUT_SACK]) &&
222 asoc->outqueue.out_qlen == 0 &&
223 list_empty(&asoc->outqueue.retransmit) &&
bfd2e4b8 224 msg_len > max_data)
d4d6c614 225 first_len -= SCTP_PAD4(sizeof(struct sctp_sack_chunk));
5d7ff261 226
1da177e4 227 /* Encourage Cookie-ECHO bundling. */
5d7ff261 228 if (asoc->state < SCTP_STATE_COOKIE_ECHOED)
bfd2e4b8 229 first_len -= SCTP_ARBITRARY_COOKIE_ECHO_LEN;
3e62abf9
VY
230
231 /* Account for a different sized first fragment */
232 if (msg_len >= first_len) {
0e3aef8d 233 msg->can_delay = 0;
6aef70a8 234 SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_FRAGUSRMSGS);
bfd2e4b8
MRL
235 } else {
236 /* Which may be the only one... */
237 first_len = msg_len;
238 }
1da177e4 239
bfd2e4b8
MRL
240 /* Create chunks for all DATA chunks. */
241 for (remaining = msg_len; remaining; remaining -= len) {
242 u8 frag = SCTP_DATA_MIDDLE_FRAG;
1da177e4 243
bfd2e4b8
MRL
244 if (remaining == msg_len) {
245 /* First frag, which may also be the last */
1da177e4 246 frag |= SCTP_DATA_FIRST_FRAG;
bfd2e4b8
MRL
247 len = first_len;
248 } else {
249 /* Middle frags */
250 len = max_data;
251 }
1da177e4 252
bfd2e4b8
MRL
253 if (len >= remaining) {
254 /* Last frag, which may also be the first */
255 len = remaining;
1da177e4
LT
256 frag |= SCTP_DATA_LAST_FRAG;
257
b93d6471
WY
258 /* The application requests to set the I-bit of the
259 * last DATA chunk of a user message when providing
260 * the user message to the SCTP implementation.
261 */
262 if ((sinfo->sinfo_flags & SCTP_EOF) ||
263 (sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
264 frag |= SCTP_DATA_SACK_IMM;
265 }
266
cea8768f
MRL
267 chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag,
268 0, GFP_KERNEL);
6e51fe75
TR
269 if (!chunk) {
270 err = -ENOMEM;
1da177e4 271 goto errout;
6e51fe75
TR
272 }
273
e0eb093e 274 err = sctp_user_addto_chunk(chunk, len, from);
1da177e4 275 if (err < 0)
be364c8c 276 goto errout_chunk_free;
1da177e4 277
1da177e4 278 /* Put the chunk->skb back into the form expected by send. */
bfd2e4b8
MRL
279 __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr -
280 chunk->skb->data);
1da177e4
LT
281
282 sctp_datamsg_assign(msg, chunk);
283 list_add_tail(&chunk->frag_list, &msg->chunks);
284 }
285
286 return msg;
287
be364c8c
TR
288errout_chunk_free:
289 sctp_chunk_free(chunk);
290
1da177e4
LT
291errout:
292 list_for_each_safe(pos, temp, &msg->chunks) {
293 list_del_init(pos);
294 chunk = list_entry(pos, struct sctp_chunk, frag_list);
295 sctp_chunk_free(chunk);
296 }
80445cfb 297 sctp_datamsg_put(msg);
bfd2e4b8 298
6e51fe75 299 return ERR_PTR(err);
1da177e4
LT
300}
301
302/* Check whether this message has expired. */
303int sctp_chunk_abandoned(struct sctp_chunk *chunk)
304{
8ae808eb 305 if (!chunk->asoc->peer.prsctp_capable)
1da177e4
LT
306 return 0;
307
e5f61296
XL
308 if (chunk->msg->abandoned)
309 return 1;
310
779edd73
XL
311 if (!chunk->has_tsn &&
312 !(chunk->chunk_hdr->flags & SCTP_DATA_FIRST_FRAG))
313 return 0;
314
a6c2f792 315 if (SCTP_PR_TTL_ENABLED(chunk->sinfo.sinfo_flags) &&
0605483f 316 time_after(jiffies, chunk->msg->expires_at)) {
d229d48d 317 struct sctp_stream_out *streamout =
cee360ab 318 &chunk->asoc->stream.out[chunk->sinfo.sinfo_stream];
d229d48d
XL
319
320 if (chunk->sent_count) {
a6c2f792 321 chunk->asoc->abandoned_sent[SCTP_PR_INDEX(TTL)]++;
f952be79 322 streamout->ext->abandoned_sent[SCTP_PR_INDEX(TTL)]++;
d229d48d 323 } else {
a6c2f792 324 chunk->asoc->abandoned_unsent[SCTP_PR_INDEX(TTL)]++;
f952be79 325 streamout->ext->abandoned_unsent[SCTP_PR_INDEX(TTL)]++;
d229d48d 326 }
e5f61296 327 chunk->msg->abandoned = 1;
1da177e4 328 return 1;
01aadb3a 329 } else if (SCTP_PR_RTX_ENABLED(chunk->sinfo.sinfo_flags) &&
0605483f 330 chunk->sent_count > chunk->sinfo.sinfo_timetolive) {
d229d48d 331 struct sctp_stream_out *streamout =
cee360ab 332 &chunk->asoc->stream.out[chunk->sinfo.sinfo_stream];
d229d48d 333
01aadb3a 334 chunk->asoc->abandoned_sent[SCTP_PR_INDEX(RTX)]++;
f952be79 335 streamout->ext->abandoned_sent[SCTP_PR_INDEX(RTX)]++;
e5f61296 336 chunk->msg->abandoned = 1;
01aadb3a 337 return 1;
8ae808eb
XL
338 } else if (!SCTP_PR_POLICY(chunk->sinfo.sinfo_flags) &&
339 chunk->msg->expires_at &&
340 time_after(jiffies, chunk->msg->expires_at)) {
e5f61296 341 chunk->msg->abandoned = 1;
8ae808eb 342 return 1;
a6c2f792 343 }
8dbdf1f5 344 /* PRIO policy is processed by sendmsg, not here */
1da177e4
LT
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}