9p: Remove INET dependency
[linux-block.git] / net / sctp / chunk.c
CommitLineData
47505b8b 1// SPDX-License-Identifier: GPL-2.0-or-later
60c778b2 2/* SCTP kernel implementation
1da177e4
LT
3 * (C) Copyright IBM Corp. 2003, 2004
4 *
60c778b2 5 * This file is part of the SCTP kernel implementation
1da177e4 6 *
59c51591 7 * This file contains the code relating the chunk abstraction.
1da177e4 8 *
1da177e4
LT
9 * Please send any bug reports or fixes you make to the
10 * email address(es):
91705c61 11 * lksctp developers <linux-sctp@vger.kernel.org>
1da177e4 12 *
1da177e4
LT
13 * Written or modified by:
14 * Jon Grimm <jgrimm@us.ibm.com>
15 * Sridhar Samudrala <sri@us.ibm.com>
1da177e4
LT
16 */
17
145ce502
JP
18#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
19
1da177e4
LT
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>
5a0e3ad6 25#include <linux/slab.h>
1da177e4
LT
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{
c0acdfb4 37 refcount_set(&msg->refcnt, 1);
1da177e4
LT
38 msg->send_failed = 0;
39 msg->send_error = 0;
0e3aef8d 40 msg->can_delay = 1;
e5f61296 41 msg->abandoned = 0;
1da177e4
LT
42 msg->expires_at = 0;
43 INIT_LIST_HEAD(&msg->chunks);
44}
45
46/* Allocate and initialize datamsg. */
dda91928 47static struct sctp_datamsg *sctp_datamsg_new(gfp_t gfp)
1da177e4
LT
48{
49 struct sctp_datamsg *msg;
50 msg = kmalloc(sizeof(struct sctp_datamsg), gfp);
e8c38751 51 if (msg) {
1da177e4 52 sctp_datamsg_init(msg);
e8c38751
LZ
53 SCTP_DBG_OBJCNT_INC(datamsg);
54 }
1da177e4
LT
55 return msg;
56}
57
b61c654f
XL
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
1da177e4
LT
71/* Final destructruction of datamsg memory. */
72static void sctp_datamsg_destroy(struct sctp_datamsg *msg)
73{
a1e3a059 74 struct sctp_association *asoc = NULL;
1da177e4
LT
75 struct list_head *pos, *temp;
76 struct sctp_chunk *chunk;
1da177e4 77 struct sctp_ulpevent *ev;
b6e6b5f1 78 int error, sent;
1da177e4
LT
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);
b6e6b5f1
XL
84
85 if (!msg->send_failed) {
86 sctp_chunk_put(chunk);
87 continue;
1da177e4
LT
88 }
89
b6e6b5f1
XL
90 asoc = chunk->asoc;
91 error = msg->send_error ?: asoc->outqueue.error;
92 sent = chunk->has_tsn ? SCTP_DATA_SENT : SCTP_DATA_UNSENT;
1da177e4 93
b6e6b5f1
XL
94 if (sctp_ulpevent_type_enabled(asoc->subscribe,
95 SCTP_SEND_FAILED)) {
1da177e4
LT
96 ev = sctp_ulpevent_make_send_failed(asoc, chunk, sent,
97 error, GFP_ATOMIC);
98 if (ev)
9162e0ed 99 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1da177e4
LT
100 }
101
b6e6b5f1
XL
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
1da177e4
LT
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{
c0acdfb4 121 refcount_inc(&msg->refcnt);
1da177e4
LT
122}
123
124/* Release a reference. */
125void sctp_datamsg_put(struct sctp_datamsg *msg)
126{
c0acdfb4 127 if (refcount_dec_and_test(&msg->refcnt))
1da177e4
LT
128 sctp_datamsg_destroy(msg);
129}
130
1da177e4
LT
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,
e0eb093e 148 struct iov_iter *from)
1da177e4 149{
bfd2e4b8
MRL
150 size_t len, first_len, max_data, remaining;
151 size_t msg_len = iov_iter_count(from);
1b1e0bc9 152 struct sctp_shared_key *shkey = NULL;
bfd2e4b8 153 struct list_head *pos, *temp;
1da177e4
LT
154 struct sctp_chunk *chunk;
155 struct sctp_datamsg *msg;
bfd2e4b8 156 int err;
1da177e4
LT
157
158 msg = sctp_datamsg_new(GFP_KERNEL);
159 if (!msg)
6e51fe75 160 return ERR_PTR(-ENOMEM);
1da177e4
LT
161
162 /* Note: Calculate this outside of the loop, so that all fragments
163 * have the same expiration.
164 */
8ae808eb
XL
165 if (asoc->peer.prsctp_capable && sinfo->sinfo_timetolive &&
166 (SCTP_PR_TTL_ENABLED(sinfo->sinfo_flags) ||
167 !SCTP_PR_POLICY(sinfo->sinfo_flags)))
1da177e4 168 msg->expires_at = jiffies +
bfd2e4b8 169 msecs_to_jiffies(sinfo->sinfo_timetolive);
0605483f 170
3e62abf9
VY
171 /* This is the biggest possible DATA chunk that can fit into
172 * the packet
173 */
2f5e3c9d 174 max_data = asoc->frag_point;
afd0a800
JA
175 if (unlikely(!max_data)) {
176 max_data = sctp_min_frag_point(sctp_sk(asoc->base.sk),
177 sctp_datachk_len(&asoc->stream));
ac510505 178 pr_warn_ratelimited("%s: asoc:%p frag_point is zero, forcing max_data to default minimum (%zu)",
afd0a800
JA
179 __func__, asoc, max_data);
180 }
1da177e4 181
9932564f 182 /* If the peer requested that we authenticate DATA chunks
2bccbadf 183 * we need to account for bundling of the AUTH chunks along with
4cd57c80
VY
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)
bb96dec7 190 max_data -= SCTP_PAD4(sizeof(struct sctp_auth_chunk) +
e2f036a9 191 hmac_desc->hmac_len);
1b1e0bc9 192
3ff547c0
XL
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 }
4cd57c80
VY
203 }
204
bfd2e4b8
MRL
205 /* Set first_len and then account for possible bundles on first frag */
206 first_len = max_data;
1da177e4 207
5d7ff261
VY
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) &&
bfd2e4b8 217 msg_len > max_data)
d4d6c614 218 first_len -= SCTP_PAD4(sizeof(struct sctp_sack_chunk));
5d7ff261 219
1da177e4 220 /* Encourage Cookie-ECHO bundling. */
5d7ff261 221 if (asoc->state < SCTP_STATE_COOKIE_ECHOED)
bfd2e4b8 222 first_len -= SCTP_ARBITRARY_COOKIE_ECHO_LEN;
3e62abf9
VY
223
224 /* Account for a different sized first fragment */
225 if (msg_len >= first_len) {
0e3aef8d 226 msg->can_delay = 0;
fedb1bd3 227 if (msg_len > first_len)
4e7696d9 228 SCTP_INC_STATS(asoc->base.net,
fedb1bd3 229 SCTP_MIB_FRAGUSRMSGS);
bfd2e4b8
MRL
230 } else {
231 /* Which may be the only one... */
232 first_len = msg_len;
233 }
1da177e4 234
bfd2e4b8
MRL
235 /* Create chunks for all DATA chunks. */
236 for (remaining = msg_len; remaining; remaining -= len) {
237 u8 frag = SCTP_DATA_MIDDLE_FRAG;
1da177e4 238
bfd2e4b8
MRL
239 if (remaining == msg_len) {
240 /* First frag, which may also be the last */
1da177e4 241 frag |= SCTP_DATA_FIRST_FRAG;
bfd2e4b8
MRL
242 len = first_len;
243 } else {
244 /* Middle frags */
245 len = max_data;
246 }
1da177e4 247
bfd2e4b8
MRL
248 if (len >= remaining) {
249 /* Last frag, which may also be the first */
250 len = remaining;
1da177e4
LT
251 frag |= SCTP_DATA_LAST_FRAG;
252
b93d6471
WY
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
0c3f6f65
XL
262 chunk = asoc->stream.si->make_datafrag(asoc, sinfo, len, frag,
263 GFP_KERNEL);
6e51fe75
TR
264 if (!chunk) {
265 err = -ENOMEM;
1da177e4 266 goto errout;
6e51fe75
TR
267 }
268
e0eb093e 269 err = sctp_user_addto_chunk(chunk, len, from);
1da177e4 270 if (err < 0)
be364c8c 271 goto errout_chunk_free;
1da177e4 272
1b1e0bc9
XL
273 chunk->shkey = shkey;
274
1da177e4 275 /* Put the chunk->skb back into the form expected by send. */
bfd2e4b8
MRL
276 __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr -
277 chunk->skb->data);
1da177e4
LT
278
279 sctp_datamsg_assign(msg, chunk);
280 list_add_tail(&chunk->frag_list, &msg->chunks);
281 }
282
283 return msg;
284
be364c8c
TR
285errout_chunk_free:
286 sctp_chunk_free(chunk);
287
1da177e4
LT
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 }
80445cfb 294 sctp_datamsg_put(msg);
bfd2e4b8 295
6e51fe75 296 return ERR_PTR(err);
1da177e4
LT
297}
298
299/* Check whether this message has expired. */
300int sctp_chunk_abandoned(struct sctp_chunk *chunk)
301{
8ae808eb 302 if (!chunk->asoc->peer.prsctp_capable)
1da177e4
LT
303 return 0;
304
e5f61296
XL
305 if (chunk->msg->abandoned)
306 return 1;
307
779edd73
XL
308 if (!chunk->has_tsn &&
309 !(chunk->chunk_hdr->flags & SCTP_DATA_FIRST_FRAG))
310 return 0;
311
a6c2f792 312 if (SCTP_PR_TTL_ENABLED(chunk->sinfo.sinfo_flags) &&
0605483f 313 time_after(jiffies, chunk->msg->expires_at)) {
d229d48d 314 struct sctp_stream_out *streamout =
05364ca0
KK
315 SCTP_SO(&chunk->asoc->stream,
316 chunk->sinfo.sinfo_stream);
d229d48d
XL
317
318 if (chunk->sent_count) {
a6c2f792 319 chunk->asoc->abandoned_sent[SCTP_PR_INDEX(TTL)]++;
f952be79 320 streamout->ext->abandoned_sent[SCTP_PR_INDEX(TTL)]++;
d229d48d 321 } else {
a6c2f792 322 chunk->asoc->abandoned_unsent[SCTP_PR_INDEX(TTL)]++;
f952be79 323 streamout->ext->abandoned_unsent[SCTP_PR_INDEX(TTL)]++;
d229d48d 324 }
e5f61296 325 chunk->msg->abandoned = 1;
1da177e4 326 return 1;
01aadb3a 327 } else if (SCTP_PR_RTX_ENABLED(chunk->sinfo.sinfo_flags) &&
0605483f 328 chunk->sent_count > chunk->sinfo.sinfo_timetolive) {
d229d48d 329 struct sctp_stream_out *streamout =
05364ca0
KK
330 SCTP_SO(&chunk->asoc->stream,
331 chunk->sinfo.sinfo_stream);
d229d48d 332
01aadb3a 333 chunk->asoc->abandoned_sent[SCTP_PR_INDEX(RTX)]++;
f952be79 334 streamout->ext->abandoned_sent[SCTP_PR_INDEX(RTX)]++;
e5f61296 335 chunk->msg->abandoned = 1;
01aadb3a 336 return 1;
8ae808eb
XL
337 } else if (!SCTP_PR_POLICY(chunk->sinfo.sinfo_flags) &&
338 chunk->msg->expires_at &&
339 time_after(jiffies, chunk->msg->expires_at)) {
e5f61296 340 chunk->msg->abandoned = 1;
8ae808eb 341 return 1;
a6c2f792 342 }
8dbdf1f5 343 /* PRIO policy is processed by sendmsg, not here */
1da177e4
LT
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}