Commit | Line | Data |
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60c778b2 | 1 | /* SCTP kernel implementation |
1da177e4 LT |
2 | * (C) Copyright IBM Corp. 2001, 2004 |
3 | * Copyright (c) 1999-2000 Cisco, Inc. | |
4 | * Copyright (c) 1999-2001 Motorola, Inc. | |
5 | * | |
60c778b2 | 6 | * This file is part of the SCTP kernel implementation |
1da177e4 LT |
7 | * |
8 | * These functions handle output processing. | |
9 | * | |
60c778b2 | 10 | * This SCTP implementation is free software; |
1da177e4 LT |
11 | * you can redistribute it and/or modify it under the terms of |
12 | * the GNU General Public License as published by | |
13 | * the Free Software Foundation; either version 2, or (at your option) | |
14 | * any later version. | |
15 | * | |
60c778b2 | 16 | * This SCTP implementation is distributed in the hope that it |
1da177e4 LT |
17 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
18 | * ************************ | |
19 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | |
20 | * See the GNU General Public License for more details. | |
21 | * | |
22 | * You should have received a copy of the GNU General Public License | |
4b2f13a2 JK |
23 | * along with GNU CC; see the file COPYING. If not, see |
24 | * <http://www.gnu.org/licenses/>. | |
1da177e4 LT |
25 | * |
26 | * Please send any bug reports or fixes you make to the | |
27 | * email address(es): | |
91705c61 | 28 | * lksctp developers <linux-sctp@vger.kernel.org> |
1da177e4 | 29 | * |
1da177e4 LT |
30 | * Written or modified by: |
31 | * La Monte H.P. Yarroll <piggy@acm.org> | |
32 | * Karl Knutson <karl@athena.chicago.il.us> | |
33 | * Jon Grimm <jgrimm@austin.ibm.com> | |
34 | * Sridhar Samudrala <sri@us.ibm.com> | |
1da177e4 LT |
35 | */ |
36 | ||
145ce502 JP |
37 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
38 | ||
1da177e4 LT |
39 | #include <linux/types.h> |
40 | #include <linux/kernel.h> | |
41 | #include <linux/wait.h> | |
42 | #include <linux/time.h> | |
43 | #include <linux/ip.h> | |
44 | #include <linux/ipv6.h> | |
45 | #include <linux/init.h> | |
5a0e3ad6 | 46 | #include <linux/slab.h> |
1da177e4 | 47 | #include <net/inet_ecn.h> |
8d2f9e81 | 48 | #include <net/ip.h> |
1da177e4 | 49 | #include <net/icmp.h> |
7c73a6fa | 50 | #include <net/net_namespace.h> |
1da177e4 | 51 | |
1da177e4 LT |
52 | #include <linux/socket.h> /* for sa_family_t */ |
53 | #include <net/sock.h> | |
54 | ||
55 | #include <net/sctp/sctp.h> | |
56 | #include <net/sctp/sm.h> | |
9ad0977f | 57 | #include <net/sctp/checksum.h> |
1da177e4 LT |
58 | |
59 | /* Forward declarations for private helpers. */ | |
86b36f2a XL |
60 | static enum sctp_xmit __sctp_packet_append_chunk(struct sctp_packet *packet, |
61 | struct sctp_chunk *chunk); | |
62 | static enum sctp_xmit sctp_packet_can_append_data(struct sctp_packet *packet, | |
63 | struct sctp_chunk *chunk); | |
e83963b7 | 64 | static void sctp_packet_append_data(struct sctp_packet *packet, |
86b36f2a XL |
65 | struct sctp_chunk *chunk); |
66 | static enum sctp_xmit sctp_packet_will_fit(struct sctp_packet *packet, | |
67 | struct sctp_chunk *chunk, | |
68 | u16 chunk_len); | |
1da177e4 | 69 | |
be297143 WY |
70 | static void sctp_packet_reset(struct sctp_packet *packet) |
71 | { | |
b7e10c25 RH |
72 | /* sctp_packet_transmit() relies on this to reset size to the |
73 | * current overhead after sending packets. | |
74 | */ | |
be297143 | 75 | packet->size = packet->overhead; |
b7e10c25 | 76 | |
be297143 WY |
77 | packet->has_cookie_echo = 0; |
78 | packet->has_sack = 0; | |
79 | packet->has_data = 0; | |
80 | packet->has_auth = 0; | |
81 | packet->ipfragok = 0; | |
82 | packet->auth = NULL; | |
83 | } | |
84 | ||
1da177e4 LT |
85 | /* Config a packet. |
86 | * This appears to be a followup set of initializations. | |
87 | */ | |
66b91d2c MRL |
88 | void sctp_packet_config(struct sctp_packet *packet, __u32 vtag, |
89 | int ecn_capable) | |
1da177e4 | 90 | { |
90017acc MRL |
91 | struct sctp_transport *tp = packet->transport; |
92 | struct sctp_association *asoc = tp->asoc; | |
feddd6c1 | 93 | struct sctp_sock *sp = NULL; |
df2729c3 | 94 | struct sock *sk; |
1da177e4 | 95 | |
bb33381d | 96 | pr_debug("%s: packet:%p vtag:0x%x\n", __func__, packet, vtag); |
1da177e4 | 97 | packet->vtag = vtag; |
1da177e4 | 98 | |
df2729c3 XL |
99 | /* do the following jobs only once for a flush schedule */ |
100 | if (!sctp_packet_empty(packet)) | |
101 | return; | |
90017acc | 102 | |
b7e10c25 | 103 | /* set packet max_size with pathmtu, then calculate overhead */ |
df2729c3 | 104 | packet->max_size = tp->pathmtu; |
feddd6c1 | 105 | |
b7e10c25 | 106 | if (asoc) { |
feddd6c1 MRL |
107 | sk = asoc->base.sk; |
108 | sp = sctp_sk(sk); | |
109 | } | |
110 | packet->overhead = sctp_mtu_payload(sp, 0, 0); | |
111 | packet->size = packet->overhead; | |
b7e10c25 | 112 | |
feddd6c1 | 113 | if (!asoc) |
df2729c3 | 114 | return; |
90017acc | 115 | |
df2729c3 | 116 | /* update dst or transport pathmtu if in need */ |
df2729c3 | 117 | if (!sctp_transport_dst_check(tp)) { |
feddd6c1 | 118 | sctp_transport_route(tp, NULL, sp); |
df2729c3 | 119 | if (asoc->param_flags & SPP_PMTUD_ENABLE) |
3ebfdf08 | 120 | sctp_assoc_sync_pmtu(asoc); |
90017acc MRL |
121 | } |
122 | ||
d805397c XL |
123 | if (asoc->pmtu_pending) { |
124 | if (asoc->param_flags & SPP_PMTUD_ENABLE) | |
125 | sctp_assoc_sync_pmtu(asoc); | |
126 | asoc->pmtu_pending = 0; | |
127 | } | |
128 | ||
df2729c3 XL |
129 | /* If there a is a prepend chunk stick it on the list before |
130 | * any other chunks get appended. | |
131 | */ | |
132 | if (ecn_capable) { | |
133 | struct sctp_chunk *chunk = sctp_get_ecne_prepend(asoc); | |
1da177e4 | 134 | |
1da177e4 LT |
135 | if (chunk) |
136 | sctp_packet_append_chunk(packet, chunk); | |
137 | } | |
df2729c3 XL |
138 | |
139 | if (!tp->dst) | |
140 | return; | |
141 | ||
142 | /* set packet max_size with gso_max_size if gso is enabled*/ | |
143 | rcu_read_lock(); | |
144 | if (__sk_dst_get(sk) != tp->dst) { | |
145 | dst_hold(tp->dst); | |
146 | sk_setup_caps(sk, tp->dst); | |
147 | } | |
148 | packet->max_size = sk_can_gso(sk) ? tp->dst->dev->gso_max_size | |
149 | : asoc->pathmtu; | |
150 | rcu_read_unlock(); | |
1da177e4 LT |
151 | } |
152 | ||
153 | /* Initialize the packet structure. */ | |
66b91d2c MRL |
154 | void sctp_packet_init(struct sctp_packet *packet, |
155 | struct sctp_transport *transport, | |
156 | __u16 sport, __u16 dport) | |
1da177e4 | 157 | { |
bb33381d | 158 | pr_debug("%s: packet:%p transport:%p\n", __func__, packet, transport); |
1da177e4 LT |
159 | |
160 | packet->transport = transport; | |
161 | packet->source_port = sport; | |
162 | packet->destination_port = dport; | |
79af02c2 | 163 | INIT_LIST_HEAD(&packet->chunk_list); |
b7e10c25 RH |
164 | /* The overhead will be calculated by sctp_packet_config() */ |
165 | packet->overhead = 0; | |
be297143 | 166 | sctp_packet_reset(packet); |
1da177e4 | 167 | packet->vtag = 0; |
1da177e4 LT |
168 | } |
169 | ||
170 | /* Free a packet. */ | |
171 | void sctp_packet_free(struct sctp_packet *packet) | |
172 | { | |
79af02c2 | 173 | struct sctp_chunk *chunk, *tmp; |
1da177e4 | 174 | |
bb33381d | 175 | pr_debug("%s: packet:%p\n", __func__, packet); |
1da177e4 | 176 | |
79af02c2 DM |
177 | list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) { |
178 | list_del_init(&chunk->list); | |
1da177e4 | 179 | sctp_chunk_free(chunk); |
79af02c2 | 180 | } |
1da177e4 LT |
181 | } |
182 | ||
183 | /* This routine tries to append the chunk to the offered packet. If adding | |
184 | * the chunk causes the packet to exceed the path MTU and COOKIE_ECHO chunk | |
185 | * is not present in the packet, it transmits the input packet. | |
186 | * Data can be bundled with a packet containing a COOKIE_ECHO chunk as long | |
187 | * as it can fit in the packet, but any more data that does not fit in this | |
188 | * packet can be sent only after receiving the COOKIE_ACK. | |
189 | */ | |
86b36f2a XL |
190 | enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet, |
191 | struct sctp_chunk *chunk, | |
192 | int one_packet, gfp_t gfp) | |
1da177e4 | 193 | { |
86b36f2a | 194 | enum sctp_xmit retval; |
1da177e4 | 195 | |
5b5e0928 | 196 | pr_debug("%s: packet:%p size:%zu chunk:%p size:%d\n", __func__, |
942b3235 | 197 | packet, packet->size, chunk, chunk->skb ? chunk->skb->len : -1); |
1da177e4 LT |
198 | |
199 | switch ((retval = (sctp_packet_append_chunk(packet, chunk)))) { | |
200 | case SCTP_XMIT_PMTU_FULL: | |
201 | if (!packet->has_cookie_echo) { | |
64519440 XL |
202 | int error = 0; |
203 | ||
cea8768f | 204 | error = sctp_packet_transmit(packet, gfp); |
1da177e4 LT |
205 | if (error < 0) |
206 | chunk->skb->sk->sk_err = -error; | |
207 | ||
208 | /* If we have an empty packet, then we can NOT ever | |
209 | * return PMTU_FULL. | |
210 | */ | |
2e3216cd VY |
211 | if (!one_packet) |
212 | retval = sctp_packet_append_chunk(packet, | |
213 | chunk); | |
1da177e4 LT |
214 | } |
215 | break; | |
216 | ||
217 | case SCTP_XMIT_RWND_FULL: | |
218 | case SCTP_XMIT_OK: | |
526cbef7 | 219 | case SCTP_XMIT_DELAY: |
1da177e4 | 220 | break; |
3ff50b79 | 221 | } |
1da177e4 LT |
222 | |
223 | return retval; | |
224 | } | |
225 | ||
4cd57c80 | 226 | /* Try to bundle an auth chunk into the packet. */ |
86b36f2a XL |
227 | static enum sctp_xmit sctp_packet_bundle_auth(struct sctp_packet *pkt, |
228 | struct sctp_chunk *chunk) | |
4cd57c80 VY |
229 | { |
230 | struct sctp_association *asoc = pkt->transport->asoc; | |
86b36f2a | 231 | enum sctp_xmit retval = SCTP_XMIT_OK; |
4cd57c80 | 232 | struct sctp_chunk *auth; |
4cd57c80 VY |
233 | |
234 | /* if we don't have an association, we can't do authentication */ | |
235 | if (!asoc) | |
236 | return retval; | |
237 | ||
238 | /* See if this is an auth chunk we are bundling or if | |
239 | * auth is already bundled. | |
240 | */ | |
4007cc88 | 241 | if (chunk->chunk_hdr->type == SCTP_CID_AUTH || pkt->has_auth) |
4cd57c80 VY |
242 | return retval; |
243 | ||
244 | /* if the peer did not request this chunk to be authenticated, | |
245 | * don't do it | |
246 | */ | |
247 | if (!chunk->auth) | |
248 | return retval; | |
249 | ||
1b1e0bc9 | 250 | auth = sctp_make_auth(asoc, chunk->shkey->key_id); |
4cd57c80 VY |
251 | if (!auth) |
252 | return retval; | |
253 | ||
1b1e0bc9 XL |
254 | auth->shkey = chunk->shkey; |
255 | sctp_auth_shkey_hold(auth->shkey); | |
256 | ||
ed106277 NH |
257 | retval = __sctp_packet_append_chunk(pkt, auth); |
258 | ||
259 | if (retval != SCTP_XMIT_OK) | |
260 | sctp_chunk_free(auth); | |
4cd57c80 VY |
261 | |
262 | return retval; | |
263 | } | |
264 | ||
1da177e4 | 265 | /* Try to bundle a SACK with the packet. */ |
86b36f2a XL |
266 | static enum sctp_xmit sctp_packet_bundle_sack(struct sctp_packet *pkt, |
267 | struct sctp_chunk *chunk) | |
1da177e4 | 268 | { |
86b36f2a | 269 | enum sctp_xmit retval = SCTP_XMIT_OK; |
1da177e4 LT |
270 | |
271 | /* If sending DATA and haven't aleady bundled a SACK, try to | |
272 | * bundle one in to the packet. | |
273 | */ | |
274 | if (sctp_chunk_is_data(chunk) && !pkt->has_sack && | |
275 | !pkt->has_cookie_echo) { | |
276 | struct sctp_association *asoc; | |
af87b823 | 277 | struct timer_list *timer; |
1da177e4 | 278 | asoc = pkt->transport->asoc; |
af87b823 | 279 | timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK]; |
1da177e4 | 280 | |
af87b823 DG |
281 | /* If the SACK timer is running, we have a pending SACK */ |
282 | if (timer_pending(timer)) { | |
1da177e4 | 283 | struct sctp_chunk *sack; |
4244854d NH |
284 | |
285 | if (pkt->transport->sack_generation != | |
286 | pkt->transport->asoc->peer.sack_generation) | |
287 | return retval; | |
288 | ||
1da177e4 LT |
289 | asoc->a_rwnd = asoc->rwnd; |
290 | sack = sctp_make_sack(asoc); | |
291 | if (sack) { | |
ed106277 NH |
292 | retval = __sctp_packet_append_chunk(pkt, sack); |
293 | if (retval != SCTP_XMIT_OK) { | |
294 | sctp_chunk_free(sack); | |
295 | goto out; | |
296 | } | |
1da177e4 | 297 | asoc->peer.sack_needed = 0; |
af87b823 | 298 | if (del_timer(timer)) |
1da177e4 LT |
299 | sctp_association_put(asoc); |
300 | } | |
301 | } | |
302 | } | |
ed106277 | 303 | out: |
1da177e4 LT |
304 | return retval; |
305 | } | |
306 | ||
ed106277 | 307 | |
1da177e4 LT |
308 | /* Append a chunk to the offered packet reporting back any inability to do |
309 | * so. | |
310 | */ | |
86b36f2a XL |
311 | static enum sctp_xmit __sctp_packet_append_chunk(struct sctp_packet *packet, |
312 | struct sctp_chunk *chunk) | |
1da177e4 | 313 | { |
e2f036a9 | 314 | __u16 chunk_len = SCTP_PAD4(ntohs(chunk->chunk_hdr->length)); |
86b36f2a | 315 | enum sctp_xmit retval = SCTP_XMIT_OK; |
1da177e4 | 316 | |
e83963b7 VY |
317 | /* Check to see if this chunk will fit into the packet */ |
318 | retval = sctp_packet_will_fit(packet, chunk, chunk_len); | |
319 | if (retval != SCTP_XMIT_OK) | |
320 | goto finish; | |
1da177e4 | 321 | |
e83963b7 | 322 | /* We believe that this chunk is OK to add to the packet */ |
4cd57c80 | 323 | switch (chunk->chunk_hdr->type) { |
f7010e61 | 324 | case SCTP_CID_DATA: |
668c9beb | 325 | case SCTP_CID_I_DATA: |
e83963b7 VY |
326 | /* Account for the data being in the packet */ |
327 | sctp_packet_append_data(packet, chunk); | |
1da177e4 LT |
328 | /* Disallow SACK bundling after DATA. */ |
329 | packet->has_sack = 1; | |
4cd57c80 VY |
330 | /* Disallow AUTH bundling after DATA */ |
331 | packet->has_auth = 1; | |
332 | /* Let it be knows that packet has DATA in it */ | |
333 | packet->has_data = 1; | |
759af00e VY |
334 | /* timestamp the chunk for rtx purposes */ |
335 | chunk->sent_at = jiffies; | |
a6c2f792 XL |
336 | /* Mainly used for prsctp RTX policy */ |
337 | chunk->sent_count++; | |
4cd57c80 | 338 | break; |
f7010e61 | 339 | case SCTP_CID_COOKIE_ECHO: |
1da177e4 | 340 | packet->has_cookie_echo = 1; |
4cd57c80 VY |
341 | break; |
342 | ||
f7010e61 | 343 | case SCTP_CID_SACK: |
1da177e4 | 344 | packet->has_sack = 1; |
196d6759 MB |
345 | if (chunk->asoc) |
346 | chunk->asoc->stats.osacks++; | |
4cd57c80 VY |
347 | break; |
348 | ||
f7010e61 | 349 | case SCTP_CID_AUTH: |
4cd57c80 VY |
350 | packet->has_auth = 1; |
351 | packet->auth = chunk; | |
352 | break; | |
353 | } | |
1da177e4 LT |
354 | |
355 | /* It is OK to send this chunk. */ | |
79af02c2 | 356 | list_add_tail(&chunk->list, &packet->chunk_list); |
1da177e4 LT |
357 | packet->size += chunk_len; |
358 | chunk->transport = packet->transport; | |
359 | finish: | |
360 | return retval; | |
361 | } | |
362 | ||
ed106277 NH |
363 | /* Append a chunk to the offered packet reporting back any inability to do |
364 | * so. | |
365 | */ | |
86b36f2a XL |
366 | enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet, |
367 | struct sctp_chunk *chunk) | |
ed106277 | 368 | { |
86b36f2a | 369 | enum sctp_xmit retval = SCTP_XMIT_OK; |
ed106277 | 370 | |
bb33381d | 371 | pr_debug("%s: packet:%p chunk:%p\n", __func__, packet, chunk); |
ed106277 NH |
372 | |
373 | /* Data chunks are special. Before seeing what else we can | |
374 | * bundle into this packet, check to see if we are allowed to | |
375 | * send this DATA. | |
376 | */ | |
377 | if (sctp_chunk_is_data(chunk)) { | |
378 | retval = sctp_packet_can_append_data(packet, chunk); | |
379 | if (retval != SCTP_XMIT_OK) | |
380 | goto finish; | |
381 | } | |
382 | ||
383 | /* Try to bundle AUTH chunk */ | |
384 | retval = sctp_packet_bundle_auth(packet, chunk); | |
385 | if (retval != SCTP_XMIT_OK) | |
386 | goto finish; | |
387 | ||
388 | /* Try to bundle SACK chunk */ | |
389 | retval = sctp_packet_bundle_sack(packet, chunk); | |
390 | if (retval != SCTP_XMIT_OK) | |
391 | goto finish; | |
392 | ||
393 | retval = __sctp_packet_append_chunk(packet, chunk); | |
394 | ||
395 | finish: | |
396 | return retval; | |
397 | } | |
398 | ||
4c3a5bda TG |
399 | static void sctp_packet_release_owner(struct sk_buff *skb) |
400 | { | |
401 | sk_free(skb->sk); | |
402 | } | |
403 | ||
404 | static void sctp_packet_set_owner_w(struct sk_buff *skb, struct sock *sk) | |
405 | { | |
406 | skb_orphan(skb); | |
407 | skb->sk = sk; | |
408 | skb->destructor = sctp_packet_release_owner; | |
409 | ||
410 | /* | |
411 | * The data chunks have already been accounted for in sctp_sendmsg(), | |
412 | * therefore only reserve a single byte to keep socket around until | |
413 | * the packet has been transmitted. | |
414 | */ | |
14afee4b | 415 | refcount_inc(&sk->sk_wmem_alloc); |
4c3a5bda TG |
416 | } |
417 | ||
99519122 XL |
418 | static void sctp_packet_gso_append(struct sk_buff *head, struct sk_buff *skb) |
419 | { | |
420 | if (SCTP_OUTPUT_CB(head)->last == head) | |
421 | skb_shinfo(head)->frag_list = skb; | |
422 | else | |
423 | SCTP_OUTPUT_CB(head)->last->next = skb; | |
424 | SCTP_OUTPUT_CB(head)->last = skb; | |
425 | ||
426 | head->truesize += skb->truesize; | |
427 | head->data_len += skb->len; | |
428 | head->len += skb->len; | |
429 | ||
430 | __skb_header_release(skb); | |
431 | } | |
432 | ||
e4ff952a XL |
433 | static int sctp_packet_pack(struct sctp_packet *packet, |
434 | struct sk_buff *head, int gso, gfp_t gfp) | |
1da177e4 LT |
435 | { |
436 | struct sctp_transport *tp = packet->transport; | |
e4ff952a | 437 | struct sctp_auth_chunk *auth = NULL; |
79af02c2 | 438 | struct sctp_chunk *chunk, *tmp; |
e4ff952a XL |
439 | int pkt_count = 0, pkt_size; |
440 | struct sock *sk = head->sk; | |
441 | struct sk_buff *nskb; | |
ecc515d7 | 442 | int auth_len = 0; |
1da177e4 | 443 | |
90017acc | 444 | if (gso) { |
90017acc | 445 | skb_shinfo(head)->gso_type = sk->sk_gso_type; |
99519122 | 446 | SCTP_OUTPUT_CB(head)->last = head; |
e4ff952a XL |
447 | } else { |
448 | nskb = head; | |
449 | pkt_size = packet->size; | |
450 | goto merge; | |
90017acc | 451 | } |
1da177e4 | 452 | |
90017acc | 453 | do { |
e4ff952a XL |
454 | /* calculate the pkt_size and alloc nskb */ |
455 | pkt_size = packet->overhead; | |
456 | list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, | |
457 | list) { | |
458 | int padded = SCTP_PAD4(chunk->skb->len); | |
6eabca54 | 459 | |
e4ff952a XL |
460 | if (chunk == packet->auth) |
461 | auth_len = padded; | |
462 | else if (auth_len + padded + packet->overhead > | |
463 | tp->pathmtu) | |
464 | return 0; | |
465 | else if (pkt_size + padded > tp->pathmtu) | |
466 | break; | |
467 | pkt_size += padded; | |
90017acc | 468 | } |
e4ff952a XL |
469 | nskb = alloc_skb(pkt_size + MAX_HEADER, gfp); |
470 | if (!nskb) | |
471 | return 0; | |
472 | skb_reserve(nskb, packet->overhead + MAX_HEADER); | |
1da177e4 | 473 | |
e4ff952a XL |
474 | merge: |
475 | /* merge chunks into nskb and append nskb into head list */ | |
90017acc MRL |
476 | pkt_size -= packet->overhead; |
477 | list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) { | |
e4ff952a XL |
478 | int padding; |
479 | ||
90017acc MRL |
480 | list_del_init(&chunk->list); |
481 | if (sctp_chunk_is_data(chunk)) { | |
cc6ac9bc XL |
482 | if (!sctp_chunk_retransmitted(chunk) && |
483 | !tp->rto_pending) { | |
90017acc MRL |
484 | chunk->rtt_in_progress = 1; |
485 | tp->rto_pending = 1; | |
486 | } | |
90017acc MRL |
487 | } |
488 | ||
e2f036a9 | 489 | padding = SCTP_PAD4(chunk->skb->len) - chunk->skb->len; |
90017acc | 490 | if (padding) |
b080db58 | 491 | skb_put_zero(chunk->skb, padding); |
90017acc | 492 | |
90017acc | 493 | if (chunk == packet->auth) |
e4ff952a XL |
494 | auth = (struct sctp_auth_chunk *) |
495 | skb_tail_pointer(nskb); | |
90017acc | 496 | |
59ae1d12 | 497 | skb_put_data(nskb, chunk->skb->data, chunk->skb->len); |
1da177e4 | 498 | |
90017acc MRL |
499 | pr_debug("*** Chunk:%p[%s] %s 0x%x, length:%d, chunk->skb->len:%d, rtt_in_progress:%d\n", |
500 | chunk, | |
501 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)), | |
502 | chunk->has_tsn ? "TSN" : "No TSN", | |
503 | chunk->has_tsn ? ntohl(chunk->subh.data_hdr->tsn) : 0, | |
504 | ntohs(chunk->chunk_hdr->length), chunk->skb->len, | |
505 | chunk->rtt_in_progress); | |
506 | ||
e2f036a9 | 507 | pkt_size -= SCTP_PAD4(chunk->skb->len); |
1da177e4 | 508 | |
f1533cce | 509 | if (!sctp_chunk_is_data(chunk) && chunk != packet->auth) |
90017acc MRL |
510 | sctp_chunk_free(chunk); |
511 | ||
512 | if (!pkt_size) | |
513 | break; | |
514 | } | |
515 | ||
e4ff952a | 516 | if (auth) { |
1b1e0bc9 XL |
517 | sctp_auth_calculate_hmac(tp->asoc, nskb, auth, |
518 | packet->auth->shkey, gfp); | |
e4ff952a XL |
519 | /* free auth if no more chunks, or add it back */ |
520 | if (list_empty(&packet->chunk_list)) | |
521 | sctp_chunk_free(packet->auth); | |
522 | else | |
1aa25ec2 XL |
523 | list_add(&packet->auth->list, |
524 | &packet->chunk_list); | |
f1533cce MRL |
525 | } |
526 | ||
99519122 XL |
527 | if (gso) |
528 | sctp_packet_gso_append(head, nskb); | |
e4ff952a XL |
529 | |
530 | pkt_count++; | |
90017acc | 531 | } while (!list_empty(&packet->chunk_list)); |
4cd57c80 | 532 | |
e4ff952a XL |
533 | if (gso) { |
534 | memset(head->cb, 0, max(sizeof(struct inet_skb_parm), | |
535 | sizeof(struct inet6_skb_parm))); | |
536 | skb_shinfo(head)->gso_segs = pkt_count; | |
537 | skb_shinfo(head)->gso_size = GSO_BY_FRAGS; | |
538 | rcu_read_lock(); | |
539 | if (skb_dst(head) != tp->dst) { | |
540 | dst_hold(tp->dst); | |
541 | sk_setup_caps(sk, tp->dst); | |
8dc92f7e | 542 | } |
e4ff952a XL |
543 | rcu_read_unlock(); |
544 | goto chksum; | |
8dc92f7e | 545 | } |
1da177e4 | 546 | |
e4ff952a XL |
547 | if (sctp_checksum_disable) |
548 | return 1; | |
1da177e4 | 549 | |
e4ff952a XL |
550 | if (!(skb_dst(head)->dev->features & NETIF_F_SCTP_CRC) || |
551 | dst_xfrm(skb_dst(head)) || packet->ipfragok) { | |
552 | struct sctphdr *sh = | |
553 | (struct sctphdr *)skb_transport_header(head); | |
1da177e4 | 554 | |
e4ff952a XL |
555 | sh->checksum = sctp_compute_cksum(head, 0); |
556 | } else { | |
557 | chksum: | |
558 | head->ip_summed = CHECKSUM_PARTIAL; | |
dba00306 | 559 | head->csum_not_inet = 1; |
e4ff952a XL |
560 | head->csum_start = skb_transport_header(head) - head->head; |
561 | head->csum_offset = offsetof(struct sctphdr, checksum); | |
1da177e4 LT |
562 | } |
563 | ||
e4ff952a XL |
564 | return pkt_count; |
565 | } | |
566 | ||
567 | /* All packets are sent to the network through this function from | |
568 | * sctp_outq_tail(). | |
569 | * | |
570 | * The return value is always 0 for now. | |
571 | */ | |
572 | int sctp_packet_transmit(struct sctp_packet *packet, gfp_t gfp) | |
573 | { | |
574 | struct sctp_transport *tp = packet->transport; | |
575 | struct sctp_association *asoc = tp->asoc; | |
576 | struct sctp_chunk *chunk, *tmp; | |
577 | int pkt_count, gso = 0; | |
578 | struct dst_entry *dst; | |
579 | struct sk_buff *head; | |
580 | struct sctphdr *sh; | |
581 | struct sock *sk; | |
1da177e4 | 582 | |
e4ff952a XL |
583 | pr_debug("%s: packet:%p\n", __func__, packet); |
584 | if (list_empty(&packet->chunk_list)) | |
585 | return 0; | |
586 | chunk = list_entry(packet->chunk_list.next, struct sctp_chunk, list); | |
587 | sk = chunk->skb->sk; | |
1da177e4 | 588 | |
e4ff952a XL |
589 | /* check gso */ |
590 | if (packet->size > tp->pathmtu && !packet->ipfragok) { | |
591 | if (!sk_can_gso(sk)) { | |
592 | pr_err_once("Trying to GSO but underlying device doesn't support it."); | |
593 | goto out; | |
1da177e4 | 594 | } |
e4ff952a XL |
595 | gso = 1; |
596 | } | |
597 | ||
598 | /* alloc head skb */ | |
599 | head = alloc_skb((gso ? packet->overhead : packet->size) + | |
600 | MAX_HEADER, gfp); | |
601 | if (!head) | |
602 | goto out; | |
603 | skb_reserve(head, packet->overhead + MAX_HEADER); | |
604 | sctp_packet_set_owner_w(head, sk); | |
605 | ||
606 | /* set sctp header */ | |
d58ff351 | 607 | sh = skb_push(head, sizeof(struct sctphdr)); |
e4ff952a XL |
608 | skb_reset_transport_header(head); |
609 | sh->source = htons(packet->source_port); | |
610 | sh->dest = htons(packet->destination_port); | |
611 | sh->vtag = htonl(packet->vtag); | |
612 | sh->checksum = 0; | |
613 | ||
df2729c3 | 614 | /* drop packet if no dst */ |
e4ff952a XL |
615 | dst = dst_clone(tp->dst); |
616 | if (!dst) { | |
617 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); | |
618 | kfree_skb(head); | |
619 | goto out; | |
620 | } | |
621 | skb_dst_set(head, dst); | |
1da177e4 | 622 | |
e4ff952a XL |
623 | /* pack up chunks */ |
624 | pkt_count = sctp_packet_pack(packet, head, gso, gfp); | |
625 | if (!pkt_count) { | |
626 | kfree_skb(head); | |
627 | goto out; | |
628 | } | |
90017acc MRL |
629 | pr_debug("***sctp_transmit_packet*** skb->len:%d\n", head->len); |
630 | ||
e4ff952a XL |
631 | /* start autoclose timer */ |
632 | if (packet->has_data && sctp_state(asoc, ESTABLISHED) && | |
633 | asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) { | |
634 | struct timer_list *timer = | |
635 | &asoc->timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE]; | |
636 | unsigned long timeout = | |
637 | asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]; | |
1da177e4 | 638 | |
e4ff952a XL |
639 | if (!mod_timer(timer, jiffies + timeout)) |
640 | sctp_association_hold(asoc); | |
641 | } | |
90017acc | 642 | |
e4ff952a XL |
643 | /* sctp xmit */ |
644 | tp->af_specific->ecn_capable(sk); | |
645 | if (asoc) { | |
646 | asoc->stats.opackets += pkt_count; | |
647 | if (asoc->peer.last_sent_to != tp) | |
648 | asoc->peer.last_sent_to = tp; | |
90017acc MRL |
649 | } |
650 | head->ignore_df = packet->ipfragok; | |
486a43db | 651 | if (tp->dst_pending_confirm) |
c86a773c JA |
652 | skb_set_dst_pending_confirm(head, 1); |
653 | /* neighbour should be confirmed on successful transmission or | |
654 | * positive error | |
655 | */ | |
486a43db XL |
656 | if (tp->af_specific->sctp_xmit(head, tp) >= 0 && |
657 | tp->dst_pending_confirm) | |
c86a773c | 658 | tp->dst_pending_confirm = 0; |
1da177e4 | 659 | |
e4ff952a | 660 | out: |
79af02c2 DM |
661 | list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) { |
662 | list_del_init(&chunk->list); | |
1da177e4 | 663 | if (!sctp_chunk_is_data(chunk)) |
d808ad9a | 664 | sctp_chunk_free(chunk); |
1da177e4 | 665 | } |
41001faf | 666 | sctp_packet_reset(packet); |
e4ff952a | 667 | return 0; |
1da177e4 LT |
668 | } |
669 | ||
670 | /******************************************************************** | |
671 | * 2nd Level Abstractions | |
672 | ********************************************************************/ | |
673 | ||
e83963b7 | 674 | /* This private function check to see if a chunk can be added */ |
86b36f2a XL |
675 | static enum sctp_xmit sctp_packet_can_append_data(struct sctp_packet *packet, |
676 | struct sctp_chunk *chunk) | |
1da177e4 | 677 | { |
e83963b7 | 678 | size_t datasize, rwnd, inflight, flight_size; |
1da177e4 | 679 | struct sctp_transport *transport = packet->transport; |
1da177e4 | 680 | struct sctp_association *asoc = transport->asoc; |
1da177e4 LT |
681 | struct sctp_outq *q = &asoc->outqueue; |
682 | ||
683 | /* RFC 2960 6.1 Transmission of DATA Chunks | |
684 | * | |
685 | * A) At any given time, the data sender MUST NOT transmit new data to | |
686 | * any destination transport address if its peer's rwnd indicates | |
687 | * that the peer has no buffer space (i.e. rwnd is 0, see Section | |
688 | * 6.2.1). However, regardless of the value of rwnd (including if it | |
689 | * is 0), the data sender can always have one DATA chunk in flight to | |
690 | * the receiver if allowed by cwnd (see rule B below). This rule | |
691 | * allows the sender to probe for a change in rwnd that the sender | |
692 | * missed due to the SACK having been lost in transit from the data | |
693 | * receiver to the data sender. | |
694 | */ | |
695 | ||
696 | rwnd = asoc->peer.rwnd; | |
e83963b7 VY |
697 | inflight = q->outstanding_bytes; |
698 | flight_size = transport->flight_size; | |
1da177e4 LT |
699 | |
700 | datasize = sctp_data_size(chunk); | |
701 | ||
723189fa DL |
702 | if (datasize > rwnd && inflight > 0) |
703 | /* We have (at least) one data chunk in flight, | |
704 | * so we can't fall back to rule 6.1 B). | |
705 | */ | |
706 | return SCTP_XMIT_RWND_FULL; | |
1da177e4 | 707 | |
1da177e4 LT |
708 | /* RFC 2960 6.1 Transmission of DATA Chunks |
709 | * | |
710 | * B) At any given time, the sender MUST NOT transmit new data | |
711 | * to a given transport address if it has cwnd or more bytes | |
712 | * of data outstanding to that transport address. | |
713 | */ | |
714 | /* RFC 7.2.4 & the Implementers Guide 2.8. | |
715 | * | |
716 | * 3) ... | |
717 | * When a Fast Retransmit is being performed the sender SHOULD | |
718 | * ignore the value of cwnd and SHOULD NOT delay retransmission. | |
719 | */ | |
723189fa DL |
720 | if (chunk->fast_retransmit != SCTP_NEED_FRTX && |
721 | flight_size >= transport->cwnd) | |
722 | return SCTP_XMIT_RWND_FULL; | |
1da177e4 LT |
723 | |
724 | /* Nagle's algorithm to solve small-packet problem: | |
725 | * Inhibit the sending of new chunks when new outgoing data arrives | |
726 | * if any previously transmitted data on the connection remains | |
727 | * unacknowledged. | |
728 | */ | |
1da177e4 | 729 | |
4ea0c32f | 730 | if ((sctp_sk(asoc->base.sk)->nodelay || inflight == 0) && |
f9ba3501 | 731 | !asoc->force_delay) |
4ea0c32f | 732 | /* Nothing unacked */ |
723189fa DL |
733 | return SCTP_XMIT_OK; |
734 | ||
735 | if (!sctp_packet_empty(packet)) | |
736 | /* Append to packet */ | |
737 | return SCTP_XMIT_OK; | |
738 | ||
723189fa DL |
739 | if (!sctp_state(asoc, ESTABLISHED)) |
740 | return SCTP_XMIT_OK; | |
741 | ||
742 | /* Check whether this chunk and all the rest of pending data will fit | |
743 | * or delay in hopes of bundling a full sized packet. | |
744 | */ | |
9f8d3147 | 745 | if (chunk->skb->len + q->out_qlen > transport->pathmtu - |
668c9beb | 746 | packet->overhead - sctp_datachk_len(&chunk->asoc->stream) - 4) |
723189fa DL |
747 | /* Enough data queued to fill a packet */ |
748 | return SCTP_XMIT_OK; | |
749 | ||
750 | /* Don't delay large message writes that may have been fragmented */ | |
751 | if (!chunk->msg->can_delay) | |
752 | return SCTP_XMIT_OK; | |
753 | ||
754 | /* Defer until all data acked or packet full */ | |
526cbef7 | 755 | return SCTP_XMIT_DELAY; |
e83963b7 VY |
756 | } |
757 | ||
758 | /* This private function does management things when adding DATA chunk */ | |
759 | static void sctp_packet_append_data(struct sctp_packet *packet, | |
760 | struct sctp_chunk *chunk) | |
761 | { | |
762 | struct sctp_transport *transport = packet->transport; | |
763 | size_t datasize = sctp_data_size(chunk); | |
764 | struct sctp_association *asoc = transport->asoc; | |
765 | u32 rwnd = asoc->peer.rwnd; | |
766 | ||
1da177e4 LT |
767 | /* Keep track of how many bytes are in flight over this transport. */ |
768 | transport->flight_size += datasize; | |
769 | ||
770 | /* Keep track of how many bytes are in flight to the receiver. */ | |
771 | asoc->outqueue.outstanding_bytes += datasize; | |
772 | ||
a76c0adf | 773 | /* Update our view of the receiver's rwnd. */ |
1da177e4 LT |
774 | if (datasize < rwnd) |
775 | rwnd -= datasize; | |
776 | else | |
777 | rwnd = 0; | |
778 | ||
779 | asoc->peer.rwnd = rwnd; | |
d8dd1578 | 780 | sctp_chunk_assign_tsn(chunk); |
668c9beb | 781 | asoc->stream.si->assign_number(chunk); |
e83963b7 VY |
782 | } |
783 | ||
86b36f2a XL |
784 | static enum sctp_xmit sctp_packet_will_fit(struct sctp_packet *packet, |
785 | struct sctp_chunk *chunk, | |
786 | u16 chunk_len) | |
e83963b7 | 787 | { |
86b36f2a | 788 | enum sctp_xmit retval = SCTP_XMIT_OK; |
7303a147 | 789 | size_t psize, pmtu, maxsize; |
e83963b7 | 790 | |
1b1e0bc9 XL |
791 | /* Don't bundle in this packet if this chunk's auth key doesn't |
792 | * match other chunks already enqueued on this packet. Also, | |
793 | * don't bundle the chunk with auth key if other chunks in this | |
794 | * packet don't have auth key. | |
795 | */ | |
796 | if ((packet->auth && chunk->shkey != packet->auth->shkey) || | |
797 | (!packet->auth && chunk->shkey && | |
798 | chunk->chunk_hdr->type != SCTP_CID_AUTH)) | |
799 | return SCTP_XMIT_PMTU_FULL; | |
800 | ||
e83963b7 | 801 | psize = packet->size; |
90017acc MRL |
802 | if (packet->transport->asoc) |
803 | pmtu = packet->transport->asoc->pathmtu; | |
804 | else | |
805 | pmtu = packet->transport->pathmtu; | |
e83963b7 VY |
806 | |
807 | /* Decide if we need to fragment or resubmit later. */ | |
90017acc MRL |
808 | if (psize + chunk_len > pmtu) { |
809 | /* It's OK to fragment at IP level if any one of the following | |
e83963b7 | 810 | * is true: |
90017acc MRL |
811 | * 1. The packet is empty (meaning this chunk is greater |
812 | * the MTU) | |
813 | * 2. The packet doesn't have any data in it yet and data | |
814 | * requires authentication. | |
e83963b7 | 815 | */ |
90017acc | 816 | if (sctp_packet_empty(packet) || |
e83963b7 VY |
817 | (!packet->has_data && chunk->auth)) { |
818 | /* We no longer do re-fragmentation. | |
819 | * Just fragment at the IP layer, if we | |
820 | * actually hit this condition | |
821 | */ | |
822 | packet->ipfragok = 1; | |
90017acc | 823 | goto out; |
e83963b7 | 824 | } |
90017acc | 825 | |
7303a147 MRL |
826 | /* Similarly, if this chunk was built before a PMTU |
827 | * reduction, we have to fragment it at IP level now. So | |
828 | * if the packet already contains something, we need to | |
829 | * flush. | |
830 | */ | |
831 | maxsize = pmtu - packet->overhead; | |
832 | if (packet->auth) | |
e2f036a9 | 833 | maxsize -= SCTP_PAD4(packet->auth->skb->len); |
7303a147 MRL |
834 | if (chunk_len > maxsize) |
835 | retval = SCTP_XMIT_PMTU_FULL; | |
836 | ||
90017acc MRL |
837 | /* It is also okay to fragment if the chunk we are |
838 | * adding is a control chunk, but only if current packet | |
839 | * is not a GSO one otherwise it causes fragmentation of | |
840 | * a large frame. So in this case we allow the | |
841 | * fragmentation by forcing it to be in a new packet. | |
842 | */ | |
843 | if (!sctp_chunk_is_data(chunk) && packet->has_data) | |
844 | retval = SCTP_XMIT_PMTU_FULL; | |
845 | ||
846 | if (psize + chunk_len > packet->max_size) | |
847 | /* Hit GSO/PMTU limit, gotta flush */ | |
848 | retval = SCTP_XMIT_PMTU_FULL; | |
849 | ||
850 | if (!packet->transport->burst_limited && | |
851 | psize + chunk_len > (packet->transport->cwnd >> 1)) | |
852 | /* Do not allow a single GSO packet to use more | |
853 | * than half of cwnd. | |
854 | */ | |
855 | retval = SCTP_XMIT_PMTU_FULL; | |
856 | ||
857 | if (packet->transport->burst_limited && | |
858 | psize + chunk_len > (packet->transport->burst_limited >> 1)) | |
859 | /* Do not allow a single GSO packet to use more | |
860 | * than half of original cwnd. | |
861 | */ | |
862 | retval = SCTP_XMIT_PMTU_FULL; | |
863 | /* Otherwise it will fit in the GSO packet */ | |
e83963b7 | 864 | } |
1da177e4 | 865 | |
90017acc | 866 | out: |
1da177e4 LT |
867 | return retval; |
868 | } |