blob: 158701da2d31c8c862fcffd59404b7c08d3b610a [file] [log] [blame]
Vlad Yasevich60c778b2008-01-11 09:57:09 -05001/* SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * (C) Copyright IBM Corp. 2003, 2004
3 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -05004 * This file is part of the SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 *
Michael Opdenacker59c51592007-05-09 08:57:56 +02006 * This file contains the code relating the chunk abstraction.
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -05008 * This SCTP implementation is free software;
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 * 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 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050014 * This SCTP implementation is distributed in the hope that it
Linus Torvalds1da177e2005-04-16 15:20:36 -070015 * 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
Jeff Kirsher4b2f13a2013-12-06 06:28:48 -080021 * along with GNU CC; see the file COPYING. If not, see
22 * <http://www.gnu.org/licenses/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -070023 *
24 * Please send any bug reports or fixes you make to the
25 * email address(es):
Daniel Borkmann91705c62013-07-23 14:51:47 +020026 * lksctp developers <linux-sctp@vger.kernel.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070028 * Written or modified by:
29 * Jon Grimm <jgrimm@us.ibm.com>
30 * Sridhar Samudrala <sri@us.ibm.com>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 */
32
Joe Perches145ce502010-08-24 13:21:08 +000033#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
34
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include <linux/types.h>
36#include <linux/kernel.h>
37#include <linux/net.h>
38#include <linux/inet.h>
39#include <linux/skbuff.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090040#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#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;
Vlad Yasevich0e3aef82010-04-30 22:41:10 -040056 msg->can_delay = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 msg->expires_at = 0;
58 INIT_LIST_HEAD(&msg->chunks);
59}
60
61/* Allocate and initialize datamsg. */
Daniel Borkmanndda91922013-06-17 11:40:05 +020062static struct sctp_datamsg *sctp_datamsg_new(gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070063{
64 struct sctp_datamsg *msg;
65 msg = kmalloc(sizeof(struct sctp_datamsg), gfp);
Li Zefane8c38752008-04-10 01:57:24 -070066 if (msg) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 sctp_datamsg_init(msg);
Li Zefane8c38752008-04-10 01:57:24 -070068 SCTP_DBG_OBJCNT_INC(datamsg);
69 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 return msg;
71}
72
Vlad Yasevich9c5c62b2009-08-10 13:51:03 -040073void 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070086/* 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150/* 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;
Vlad Yasevich3e62abf2009-09-04 18:20:56 -0400171 int max_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 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)
Tommi Rantala6e51fe72012-11-22 03:23:16 +0000179 return ERR_PTR(-ENOMEM);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
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;
Daniel Borkmannbb333812013-06-28 19:49:40 +0200189
190 pr_debug("%s: msg:%p expires_at:%ld jiffies:%ld\n", __func__,
191 msg, msg->expires_at, jiffies);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 }
193
Vlad Yasevich3e62abf2009-09-04 18:20:56 -0400194 /* This is the biggest possible DATA chunk that can fit into
195 * the packet
196 */
Alexander Sverdlinc08751c2013-09-02 15:58:25 +0200197 max_data = (asoc->pathmtu -
Vlad Yasevich3e62abf2009-09-04 18:20:56 -0400198 sctp_sk(asoc->base.sk)->pf->af->net_header_len -
Alexander Sverdlinc08751c2013-09-02 15:58:25 +0200199 sizeof(struct sctphdr) - sizeof(struct sctp_data_chunk)) & ~3;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200
Vlad Yasevich3e62abf2009-09-04 18:20:56 -0400201 max = asoc->frag_point;
Vlad Yasevich4cd57c82007-09-16 19:32:45 -0700202 /* If the the peer requested that we authenticate DATA chunks
wangweidong2bccbad2013-10-26 16:06:30 +0800203 * we need to account for bundling of the AUTH chunks along with
Vlad Yasevich4cd57c82007-09-16 19:32:45 -0700204 * 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)
Vlad Yasevich3e62abf2009-09-04 18:20:56 -0400210 max_data -= WORD_ROUND(sizeof(sctp_auth_chunk_t) +
Vlad Yasevich4cd57c82007-09-16 19:32:45 -0700211 hmac_desc->hmac_len);
212 }
213
Vlad Yasevich3e62abf2009-09-04 18:20:56 -0400214 /* Now, check if we need to reduce our max */
215 if (max > max_data)
216 max = max_data;
217
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 whole = 0;
219 first_len = max;
220
Vlad Yasevich5d7ff262009-08-07 13:23:28 -0400221 /* 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 /* Encourage Cookie-ECHO bundling. */
Vlad Yasevich5d7ff262009-08-07 13:23:28 -0400234 if (asoc->state < SCTP_STATE_COOKIE_ECHOED)
Vlad Yasevich3e62abf2009-09-04 18:20:56 -0400235 max_data -= SCTP_ARBITRARY_COOKIE_ECHO_LEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236
Vlad Yasevich5d7ff262009-08-07 13:23:28 -0400237 /* Now that we adjusted completely, reset first_len */
238 if (first_len > max_data)
239 first_len = max_data;
Vlad Yasevich3e62abf2009-09-04 18:20:56 -0400240
241 /* Account for a different sized first fragment */
242 if (msg_len >= first_len) {
243 msg_len -= first_len;
244 whole = 1;
Vlad Yasevich0e3aef82010-04-30 22:41:10 -0400245 msg->can_delay = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 }
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))
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000254 SCTP_INC_STATS_USER(sock_net(asoc->base.sk), SCTP_MIB_FRAGUSRMSGS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
256 /* Create chunks for all the full sized DATA chunks. */
wangweidongcb3f8372013-12-23 12:16:50 +0800257 for (i = 0, len = first_len; i < whole; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 frag = SCTP_DATA_MIDDLE_FRAG;
259
260 if (0 == i)
261 frag |= SCTP_DATA_FIRST_FRAG;
262
Wei Yongjunb93d6472009-11-23 15:53:56 -0500263 if ((i == (whole - 1)) && !over) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 frag |= SCTP_DATA_LAST_FRAG;
265
Wei Yongjunb93d6472009-11-23 15:53:56 -0500266 /* 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag, 0);
276
Tommi Rantala6e51fe72012-11-22 03:23:16 +0000277 if (!chunk) {
278 err = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 goto errout;
Tommi Rantala6e51fe72012-11-22 03:23:16 +0000280 }
281
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 err = sctp_user_addto_chunk(chunk, offset, len, msgh->msg_iov);
283 if (err < 0)
Tommi Rantalabe364c82012-11-27 04:01:46 +0000284 goto errout_chunk_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285
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
Wei Yongjunb93d6472009-11-23 15:53:56 -0500309 if ((sinfo->sinfo_flags & SCTP_EOF) ||
310 (sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
311 frag |= SCTP_DATA_SACK_IMM;
312
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 chunk = sctp_make_datafrag_empty(asoc, sinfo, over, frag, 0);
314
Tommi Rantala6e51fe72012-11-22 03:23:16 +0000315 if (!chunk) {
316 err = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 goto errout;
Tommi Rantala6e51fe72012-11-22 03:23:16 +0000318 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319
wangweidongcb3f8372013-12-23 12:16:50 +0800320 err = sctp_user_addto_chunk(chunk, offset, over, msgh->msg_iov);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321
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)
Tommi Rantalabe364c82012-11-27 04:01:46 +0000326 goto errout_chunk_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327
328 sctp_datamsg_assign(msg, chunk);
329 list_add_tail(&chunk->frag_list, &msg->chunks);
330 }
331
332 return msg;
333
Tommi Rantalabe364c82012-11-27 04:01:46 +0000334errout_chunk_free:
335 sctp_chunk_free(chunk);
336
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337errout:
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 }
Florian Westphal80445cf2008-03-23 22:47:08 -0700343 sctp_datamsg_put(msg);
Tommi Rantala6e51fe72012-11-22 03:23:16 +0000344 return ERR_PTR(err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345}
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}