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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. */ | |
50 | static 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; | |
0e3aef8d | 56 | msg->can_delay = 1; |
1da177e4 LT |
57 | msg->expires_at = 0; |
58 | INIT_LIST_HEAD(&msg->chunks); | |
59 | } | |
60 | ||
61 | /* Allocate and initialize datamsg. */ | |
dda91928 | 62 | static 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 |
73 | void 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. */ |
87 | static 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. */ | |
138 | static void sctp_datamsg_hold(struct sctp_datamsg *msg) | |
139 | { | |
140 | atomic_inc(&msg->refcnt); | |
141 | } | |
142 | ||
143 | /* Release a reference. */ | |
144 | void sctp_datamsg_put(struct sctp_datamsg *msg) | |
145 | { | |
146 | if (atomic_dec_and_test(&msg->refcnt)) | |
147 | sctp_datamsg_destroy(msg); | |
148 | } | |
149 | ||
1da177e4 LT |
150 | /* Assign a chunk to this datamsg. */ |
151 | static 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 | */ | |
165 | struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, | |
166 | struct sctp_sndrcvinfo *sinfo, | |
e0eb093e | 167 | struct iov_iter *from) |
1da177e4 LT |
168 | { |
169 | int max, whole, i, offset, over, err; | |
170 | int len, first_len; | |
3e62abf9 | 171 | int max_data; |
1da177e4 LT |
172 | struct sctp_chunk *chunk; |
173 | struct sctp_datamsg *msg; | |
174 | struct list_head *pos, *temp; | |
e0eb093e | 175 | size_t msg_len = iov_iter_count(from); |
1da177e4 LT |
176 | __u8 frag; |
177 | ||
178 | msg = sctp_datamsg_new(GFP_KERNEL); | |
179 | if (!msg) | |
6e51fe75 | 180 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
181 | |
182 | /* Note: Calculate this outside of the loop, so that all fragments | |
183 | * have the same expiration. | |
184 | */ | |
185 | if (sinfo->sinfo_timetolive) { | |
186 | /* sinfo_timetolive is in milliseconds */ | |
187 | msg->expires_at = jiffies + | |
188 | msecs_to_jiffies(sinfo->sinfo_timetolive); | |
189 | msg->can_abandon = 1; | |
bb33381d DB |
190 | |
191 | pr_debug("%s: msg:%p expires_at:%ld jiffies:%ld\n", __func__, | |
192 | msg, msg->expires_at, jiffies); | |
1da177e4 LT |
193 | } |
194 | ||
3e62abf9 VY |
195 | /* This is the biggest possible DATA chunk that can fit into |
196 | * the packet | |
197 | */ | |
c08751c8 | 198 | max_data = (asoc->pathmtu - |
3e62abf9 | 199 | sctp_sk(asoc->base.sk)->pf->af->net_header_len - |
c08751c8 | 200 | sizeof(struct sctphdr) - sizeof(struct sctp_data_chunk)) & ~3; |
1da177e4 | 201 | |
3e62abf9 | 202 | max = asoc->frag_point; |
4cd57c80 | 203 | /* If the the peer requested that we authenticate DATA chunks |
2bccbadf | 204 | * we need to account for bundling of the AUTH chunks along with |
4cd57c80 VY |
205 | * DATA. |
206 | */ | |
207 | if (sctp_auth_send_cid(SCTP_CID_DATA, asoc)) { | |
208 | struct sctp_hmac *hmac_desc = sctp_auth_asoc_get_hmac(asoc); | |
209 | ||
210 | if (hmac_desc) | |
e2f036a9 MRL |
211 | max_data -= SCTP_PAD4(sizeof(sctp_auth_chunk_t) + |
212 | hmac_desc->hmac_len); | |
4cd57c80 VY |
213 | } |
214 | ||
3e62abf9 VY |
215 | /* Now, check if we need to reduce our max */ |
216 | if (max > max_data) | |
217 | max = max_data; | |
218 | ||
1da177e4 LT |
219 | whole = 0; |
220 | first_len = max; | |
221 | ||
5d7ff261 VY |
222 | /* Check to see if we have a pending SACK and try to let it be bundled |
223 | * with this message. Do this if we don't have any data queued already. | |
224 | * To check that, look at out_qlen and retransmit list. | |
225 | * NOTE: we will not reduce to account for SACK, if the message would | |
226 | * not have been fragmented. | |
227 | */ | |
228 | if (timer_pending(&asoc->timers[SCTP_EVENT_TIMEOUT_SACK]) && | |
229 | asoc->outqueue.out_qlen == 0 && | |
230 | list_empty(&asoc->outqueue.retransmit) && | |
231 | msg_len > max) | |
e2f036a9 | 232 | max_data -= SCTP_PAD4(sizeof(sctp_sack_chunk_t)); |
5d7ff261 | 233 | |
1da177e4 | 234 | /* Encourage Cookie-ECHO bundling. */ |
5d7ff261 | 235 | if (asoc->state < SCTP_STATE_COOKIE_ECHOED) |
3e62abf9 | 236 | max_data -= SCTP_ARBITRARY_COOKIE_ECHO_LEN; |
1da177e4 | 237 | |
5d7ff261 VY |
238 | /* Now that we adjusted completely, reset first_len */ |
239 | if (first_len > max_data) | |
240 | first_len = max_data; | |
3e62abf9 VY |
241 | |
242 | /* Account for a different sized first fragment */ | |
243 | if (msg_len >= first_len) { | |
244 | msg_len -= first_len; | |
245 | whole = 1; | |
0e3aef8d | 246 | msg->can_delay = 0; |
1da177e4 LT |
247 | } |
248 | ||
249 | /* How many full sized? How many bytes leftover? */ | |
250 | whole += msg_len / max; | |
251 | over = msg_len % max; | |
252 | offset = 0; | |
253 | ||
254 | if ((whole > 1) || (whole && over)) | |
6aef70a8 | 255 | SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_FRAGUSRMSGS); |
1da177e4 LT |
256 | |
257 | /* Create chunks for all the full sized DATA chunks. */ | |
cb3f837b | 258 | for (i = 0, len = first_len; i < whole; i++) { |
1da177e4 LT |
259 | frag = SCTP_DATA_MIDDLE_FRAG; |
260 | ||
261 | if (0 == i) | |
262 | frag |= SCTP_DATA_FIRST_FRAG; | |
263 | ||
b93d6471 | 264 | if ((i == (whole - 1)) && !over) { |
1da177e4 LT |
265 | frag |= SCTP_DATA_LAST_FRAG; |
266 | ||
b93d6471 WY |
267 | /* The application requests to set the I-bit of the |
268 | * last DATA chunk of a user message when providing | |
269 | * the user message to the SCTP implementation. | |
270 | */ | |
271 | if ((sinfo->sinfo_flags & SCTP_EOF) || | |
272 | (sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY)) | |
273 | frag |= SCTP_DATA_SACK_IMM; | |
274 | } | |
275 | ||
cea8768f MRL |
276 | chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag, |
277 | 0, GFP_KERNEL); | |
1da177e4 | 278 | |
6e51fe75 TR |
279 | if (!chunk) { |
280 | err = -ENOMEM; | |
1da177e4 | 281 | goto errout; |
6e51fe75 TR |
282 | } |
283 | ||
e0eb093e | 284 | err = sctp_user_addto_chunk(chunk, len, from); |
1da177e4 | 285 | if (err < 0) |
be364c8c | 286 | goto errout_chunk_free; |
1da177e4 | 287 | |
1da177e4 LT |
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 | ||
b93d6471 WY |
309 | if ((sinfo->sinfo_flags & SCTP_EOF) || |
310 | (sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY)) | |
311 | frag |= SCTP_DATA_SACK_IMM; | |
312 | ||
cea8768f MRL |
313 | chunk = sctp_make_datafrag_empty(asoc, sinfo, over, frag, |
314 | 0, GFP_KERNEL); | |
1da177e4 | 315 | |
6e51fe75 TR |
316 | if (!chunk) { |
317 | err = -ENOMEM; | |
1da177e4 | 318 | goto errout; |
6e51fe75 | 319 | } |
1da177e4 | 320 | |
e0eb093e | 321 | err = sctp_user_addto_chunk(chunk, over, from); |
1da177e4 LT |
322 | |
323 | /* Put the chunk->skb back into the form expected by send. */ | |
324 | __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr | |
325 | - (__u8 *)chunk->skb->data); | |
326 | if (err < 0) | |
be364c8c | 327 | goto errout_chunk_free; |
1da177e4 LT |
328 | |
329 | sctp_datamsg_assign(msg, chunk); | |
330 | list_add_tail(&chunk->frag_list, &msg->chunks); | |
331 | } | |
332 | ||
333 | return msg; | |
334 | ||
be364c8c TR |
335 | errout_chunk_free: |
336 | sctp_chunk_free(chunk); | |
337 | ||
1da177e4 LT |
338 | errout: |
339 | list_for_each_safe(pos, temp, &msg->chunks) { | |
340 | list_del_init(pos); | |
341 | chunk = list_entry(pos, struct sctp_chunk, frag_list); | |
342 | sctp_chunk_free(chunk); | |
343 | } | |
80445cfb | 344 | sctp_datamsg_put(msg); |
6e51fe75 | 345 | return ERR_PTR(err); |
1da177e4 LT |
346 | } |
347 | ||
348 | /* Check whether this message has expired. */ | |
349 | int sctp_chunk_abandoned(struct sctp_chunk *chunk) | |
350 | { | |
a6c2f792 XL |
351 | if (!chunk->asoc->prsctp_enable || |
352 | !SCTP_PR_POLICY(chunk->sinfo.sinfo_flags)) { | |
353 | struct sctp_datamsg *msg = chunk->msg; | |
354 | ||
355 | if (!msg->can_abandon) | |
356 | return 0; | |
357 | ||
358 | if (time_after(jiffies, msg->expires_at)) | |
359 | return 1; | |
1da177e4 | 360 | |
1da177e4 | 361 | return 0; |
a6c2f792 | 362 | } |
1da177e4 | 363 | |
a6c2f792 XL |
364 | if (SCTP_PR_TTL_ENABLED(chunk->sinfo.sinfo_flags) && |
365 | time_after(jiffies, chunk->prsctp_param)) { | |
366 | if (chunk->sent_count) | |
367 | chunk->asoc->abandoned_sent[SCTP_PR_INDEX(TTL)]++; | |
368 | else | |
369 | chunk->asoc->abandoned_unsent[SCTP_PR_INDEX(TTL)]++; | |
1da177e4 | 370 | return 1; |
01aadb3a XL |
371 | } else if (SCTP_PR_RTX_ENABLED(chunk->sinfo.sinfo_flags) && |
372 | chunk->sent_count > chunk->prsctp_param) { | |
373 | chunk->asoc->abandoned_sent[SCTP_PR_INDEX(RTX)]++; | |
374 | return 1; | |
a6c2f792 | 375 | } |
8dbdf1f5 | 376 | /* PRIO policy is processed by sendmsg, not here */ |
1da177e4 LT |
377 | |
378 | return 0; | |
379 | } | |
380 | ||
381 | /* This chunk (and consequently entire message) has failed in its sending. */ | |
382 | void sctp_chunk_fail(struct sctp_chunk *chunk, int error) | |
383 | { | |
384 | chunk->msg->send_failed = 1; | |
385 | chunk->msg->send_error = error; | |
386 | } |