Commit | Line | Data |
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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 | { | |
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; |
1da177e4 LT |
56 | msg->expires_at = 0; |
57 | INIT_LIST_HEAD(&msg->chunks); | |
58 | } | |
59 | ||
60 | /* Allocate and initialize datamsg. */ | |
dda91928 | 61 | static struct sctp_datamsg *sctp_datamsg_new(gfp_t gfp) |
1da177e4 LT |
62 | { |
63 | struct sctp_datamsg *msg; | |
64 | msg = kmalloc(sizeof(struct sctp_datamsg), gfp); | |
e8c38751 | 65 | if (msg) { |
1da177e4 | 66 | sctp_datamsg_init(msg); |
e8c38751 LZ |
67 | SCTP_DBG_OBJCNT_INC(datamsg); |
68 | } | |
1da177e4 LT |
69 | return msg; |
70 | } | |
71 | ||
b61c654f XL |
72 | void sctp_datamsg_free(struct sctp_datamsg *msg) |
73 | { | |
74 | struct sctp_chunk *chunk; | |
75 | ||
76 | /* This doesn't have to be a _safe vairant because | |
77 | * sctp_chunk_free() only drops the refs. | |
78 | */ | |
79 | list_for_each_entry(chunk, &msg->chunks, frag_list) | |
80 | sctp_chunk_free(chunk); | |
81 | ||
82 | sctp_datamsg_put(msg); | |
83 | } | |
84 | ||
1da177e4 LT |
85 | /* Final destructruction of datamsg memory. */ |
86 | static void sctp_datamsg_destroy(struct sctp_datamsg *msg) | |
87 | { | |
88 | struct list_head *pos, *temp; | |
89 | struct sctp_chunk *chunk; | |
90 | struct sctp_sock *sp; | |
91 | struct sctp_ulpevent *ev; | |
92 | struct sctp_association *asoc = NULL; | |
93 | int error = 0, notify; | |
94 | ||
95 | /* If we failed, we may need to notify. */ | |
96 | notify = msg->send_failed ? -1 : 0; | |
97 | ||
98 | /* Release all references. */ | |
99 | list_for_each_safe(pos, temp, &msg->chunks) { | |
100 | list_del_init(pos); | |
101 | chunk = list_entry(pos, struct sctp_chunk, frag_list); | |
102 | /* Check whether we _really_ need to notify. */ | |
103 | if (notify < 0) { | |
104 | asoc = chunk->asoc; | |
105 | if (msg->send_error) | |
106 | error = msg->send_error; | |
107 | else | |
108 | error = asoc->outqueue.error; | |
109 | ||
110 | sp = sctp_sk(asoc->base.sk); | |
111 | notify = sctp_ulpevent_type_enabled(SCTP_SEND_FAILED, | |
112 | &sp->subscribe); | |
113 | } | |
114 | ||
115 | /* Generate a SEND FAILED event only if enabled. */ | |
116 | if (notify > 0) { | |
117 | int sent; | |
118 | if (chunk->has_tsn) | |
119 | sent = SCTP_DATA_SENT; | |
120 | else | |
121 | sent = SCTP_DATA_UNSENT; | |
122 | ||
123 | ev = sctp_ulpevent_make_send_failed(asoc, chunk, sent, | |
124 | error, GFP_ATOMIC); | |
125 | if (ev) | |
126 | sctp_ulpq_tail_event(&asoc->ulpq, ev); | |
127 | } | |
128 | ||
129 | sctp_chunk_put(chunk); | |
130 | } | |
131 | ||
132 | SCTP_DBG_OBJCNT_DEC(datamsg); | |
133 | kfree(msg); | |
134 | } | |
135 | ||
136 | /* Hold a reference. */ | |
137 | static void sctp_datamsg_hold(struct sctp_datamsg *msg) | |
138 | { | |
c0acdfb4 | 139 | refcount_inc(&msg->refcnt); |
1da177e4 LT |
140 | } |
141 | ||
142 | /* Release a reference. */ | |
143 | void sctp_datamsg_put(struct sctp_datamsg *msg) | |
144 | { | |
c0acdfb4 | 145 | if (refcount_dec_and_test(&msg->refcnt)) |
1da177e4 LT |
146 | sctp_datamsg_destroy(msg); |
147 | } | |
148 | ||
1da177e4 LT |
149 | /* Assign a chunk to this datamsg. */ |
150 | static void sctp_datamsg_assign(struct sctp_datamsg *msg, struct sctp_chunk *chunk) | |
151 | { | |
152 | sctp_datamsg_hold(msg); | |
153 | chunk->msg = msg; | |
154 | } | |
155 | ||
156 | ||
157 | /* A data chunk can have a maximum payload of (2^16 - 20). Break | |
158 | * down any such message into smaller chunks. Opportunistically, fragment | |
159 | * the chunks down to the current MTU constraints. We may get refragmented | |
160 | * later if the PMTU changes, but it is _much better_ to fragment immediately | |
161 | * with a reasonable guess than always doing our fragmentation on the | |
162 | * soft-interrupt. | |
163 | */ | |
164 | struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, | |
165 | struct sctp_sndrcvinfo *sinfo, | |
e0eb093e | 166 | struct iov_iter *from) |
1da177e4 | 167 | { |
bfd2e4b8 MRL |
168 | size_t len, first_len, max_data, remaining; |
169 | size_t msg_len = iov_iter_count(from); | |
170 | struct list_head *pos, *temp; | |
1da177e4 LT |
171 | struct sctp_chunk *chunk; |
172 | struct sctp_datamsg *msg; | |
bfd2e4b8 | 173 | int err; |
1da177e4 LT |
174 | |
175 | msg = sctp_datamsg_new(GFP_KERNEL); | |
176 | if (!msg) | |
6e51fe75 | 177 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
178 | |
179 | /* Note: Calculate this outside of the loop, so that all fragments | |
180 | * have the same expiration. | |
181 | */ | |
8ae808eb XL |
182 | if (asoc->peer.prsctp_capable && sinfo->sinfo_timetolive && |
183 | (SCTP_PR_TTL_ENABLED(sinfo->sinfo_flags) || | |
184 | !SCTP_PR_POLICY(sinfo->sinfo_flags))) | |
1da177e4 | 185 | msg->expires_at = jiffies + |
bfd2e4b8 | 186 | msecs_to_jiffies(sinfo->sinfo_timetolive); |
0605483f | 187 | |
3e62abf9 VY |
188 | /* This is the biggest possible DATA chunk that can fit into |
189 | * the packet | |
190 | */ | |
4a225ce3 MRL |
191 | max_data = asoc->pathmtu - |
192 | sctp_sk(asoc->base.sk)->pf->af->net_header_len - | |
193 | sizeof(struct sctphdr) - sizeof(struct sctp_data_chunk); | |
194 | max_data = SCTP_TRUNC4(max_data); | |
1da177e4 | 195 | |
4cd57c80 | 196 | /* If the the peer requested that we authenticate DATA chunks |
2bccbadf | 197 | * we need to account for bundling of the AUTH chunks along with |
4cd57c80 VY |
198 | * DATA. |
199 | */ | |
200 | if (sctp_auth_send_cid(SCTP_CID_DATA, asoc)) { | |
201 | struct sctp_hmac *hmac_desc = sctp_auth_asoc_get_hmac(asoc); | |
202 | ||
203 | if (hmac_desc) | |
bb96dec7 | 204 | max_data -= SCTP_PAD4(sizeof(struct sctp_auth_chunk) + |
e2f036a9 | 205 | hmac_desc->hmac_len); |
4cd57c80 VY |
206 | } |
207 | ||
bfd2e4b8 MRL |
208 | /* Check what's our max considering the above */ |
209 | max_data = min_t(size_t, max_data, asoc->frag_point); | |
3e62abf9 | 210 | |
bfd2e4b8 MRL |
211 | /* Set first_len and then account for possible bundles on first frag */ |
212 | first_len = max_data; | |
1da177e4 | 213 | |
5d7ff261 VY |
214 | /* Check to see if we have a pending SACK and try to let it be bundled |
215 | * with this message. Do this if we don't have any data queued already. | |
216 | * To check that, look at out_qlen and retransmit list. | |
217 | * NOTE: we will not reduce to account for SACK, if the message would | |
218 | * not have been fragmented. | |
219 | */ | |
220 | if (timer_pending(&asoc->timers[SCTP_EVENT_TIMEOUT_SACK]) && | |
221 | asoc->outqueue.out_qlen == 0 && | |
222 | list_empty(&asoc->outqueue.retransmit) && | |
bfd2e4b8 | 223 | msg_len > max_data) |
d4d6c614 | 224 | first_len -= SCTP_PAD4(sizeof(struct sctp_sack_chunk)); |
5d7ff261 | 225 | |
1da177e4 | 226 | /* Encourage Cookie-ECHO bundling. */ |
5d7ff261 | 227 | if (asoc->state < SCTP_STATE_COOKIE_ECHOED) |
bfd2e4b8 | 228 | first_len -= SCTP_ARBITRARY_COOKIE_ECHO_LEN; |
3e62abf9 VY |
229 | |
230 | /* Account for a different sized first fragment */ | |
231 | if (msg_len >= first_len) { | |
0e3aef8d | 232 | msg->can_delay = 0; |
8fb20507 MRL |
233 | if (msg_len > first_len) |
234 | SCTP_INC_STATS(sock_net(asoc->base.sk), | |
235 | SCTP_MIB_FRAGUSRMSGS); | |
bfd2e4b8 MRL |
236 | } else { |
237 | /* Which may be the only one... */ | |
238 | first_len = msg_len; | |
239 | } | |
1da177e4 | 240 | |
bfd2e4b8 MRL |
241 | /* Create chunks for all DATA chunks. */ |
242 | for (remaining = msg_len; remaining; remaining -= len) { | |
243 | u8 frag = SCTP_DATA_MIDDLE_FRAG; | |
1da177e4 | 244 | |
bfd2e4b8 MRL |
245 | if (remaining == msg_len) { |
246 | /* First frag, which may also be the last */ | |
1da177e4 | 247 | frag |= SCTP_DATA_FIRST_FRAG; |
bfd2e4b8 MRL |
248 | len = first_len; |
249 | } else { | |
250 | /* Middle frags */ | |
251 | len = max_data; | |
252 | } | |
1da177e4 | 253 | |
bfd2e4b8 MRL |
254 | if (len >= remaining) { |
255 | /* Last frag, which may also be the first */ | |
256 | len = remaining; | |
1da177e4 LT |
257 | frag |= SCTP_DATA_LAST_FRAG; |
258 | ||
b93d6471 WY |
259 | /* The application requests to set the I-bit of the |
260 | * last DATA chunk of a user message when providing | |
261 | * the user message to the SCTP implementation. | |
262 | */ | |
263 | if ((sinfo->sinfo_flags & SCTP_EOF) || | |
264 | (sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY)) | |
265 | frag |= SCTP_DATA_SACK_IMM; | |
266 | } | |
267 | ||
cea8768f MRL |
268 | chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag, |
269 | 0, GFP_KERNEL); | |
6e51fe75 TR |
270 | if (!chunk) { |
271 | err = -ENOMEM; | |
1da177e4 | 272 | goto errout; |
6e51fe75 TR |
273 | } |
274 | ||
e0eb093e | 275 | err = sctp_user_addto_chunk(chunk, len, from); |
1da177e4 | 276 | if (err < 0) |
be364c8c | 277 | goto errout_chunk_free; |
1da177e4 | 278 | |
1da177e4 | 279 | /* Put the chunk->skb back into the form expected by send. */ |
bfd2e4b8 MRL |
280 | __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr - |
281 | chunk->skb->data); | |
1da177e4 LT |
282 | |
283 | sctp_datamsg_assign(msg, chunk); | |
284 | list_add_tail(&chunk->frag_list, &msg->chunks); | |
285 | } | |
286 | ||
287 | return msg; | |
288 | ||
be364c8c TR |
289 | errout_chunk_free: |
290 | sctp_chunk_free(chunk); | |
291 | ||
1da177e4 LT |
292 | errout: |
293 | list_for_each_safe(pos, temp, &msg->chunks) { | |
294 | list_del_init(pos); | |
295 | chunk = list_entry(pos, struct sctp_chunk, frag_list); | |
296 | sctp_chunk_free(chunk); | |
297 | } | |
80445cfb | 298 | sctp_datamsg_put(msg); |
bfd2e4b8 | 299 | |
6e51fe75 | 300 | return ERR_PTR(err); |
1da177e4 LT |
301 | } |
302 | ||
303 | /* Check whether this message has expired. */ | |
304 | int sctp_chunk_abandoned(struct sctp_chunk *chunk) | |
305 | { | |
8ae808eb | 306 | if (!chunk->asoc->peer.prsctp_capable) |
1da177e4 LT |
307 | return 0; |
308 | ||
a6c2f792 | 309 | if (SCTP_PR_TTL_ENABLED(chunk->sinfo.sinfo_flags) && |
0605483f | 310 | time_after(jiffies, chunk->msg->expires_at)) { |
d229d48d | 311 | struct sctp_stream_out *streamout = |
cee360ab | 312 | &chunk->asoc->stream.out[chunk->sinfo.sinfo_stream]; |
d229d48d XL |
313 | |
314 | if (chunk->sent_count) { | |
a6c2f792 | 315 | chunk->asoc->abandoned_sent[SCTP_PR_INDEX(TTL)]++; |
d229d48d XL |
316 | streamout->abandoned_sent[SCTP_PR_INDEX(TTL)]++; |
317 | } else { | |
a6c2f792 | 318 | chunk->asoc->abandoned_unsent[SCTP_PR_INDEX(TTL)]++; |
d229d48d XL |
319 | streamout->abandoned_unsent[SCTP_PR_INDEX(TTL)]++; |
320 | } | |
1da177e4 | 321 | return 1; |
01aadb3a | 322 | } else if (SCTP_PR_RTX_ENABLED(chunk->sinfo.sinfo_flags) && |
0605483f | 323 | chunk->sent_count > chunk->sinfo.sinfo_timetolive) { |
d229d48d | 324 | struct sctp_stream_out *streamout = |
cee360ab | 325 | &chunk->asoc->stream.out[chunk->sinfo.sinfo_stream]; |
d229d48d | 326 | |
01aadb3a | 327 | chunk->asoc->abandoned_sent[SCTP_PR_INDEX(RTX)]++; |
d229d48d | 328 | streamout->abandoned_sent[SCTP_PR_INDEX(RTX)]++; |
01aadb3a | 329 | return 1; |
8ae808eb XL |
330 | } else if (!SCTP_PR_POLICY(chunk->sinfo.sinfo_flags) && |
331 | chunk->msg->expires_at && | |
332 | time_after(jiffies, chunk->msg->expires_at)) { | |
333 | return 1; | |
a6c2f792 | 334 | } |
8dbdf1f5 | 335 | /* PRIO policy is processed by sendmsg, not here */ |
1da177e4 LT |
336 | |
337 | return 0; | |
338 | } | |
339 | ||
340 | /* This chunk (and consequently entire message) has failed in its sending. */ | |
341 | void sctp_chunk_fail(struct sctp_chunk *chunk, int error) | |
342 | { | |
343 | chunk->msg->send_failed = 1; | |
344 | chunk->msg->send_error = error; | |
345 | } |