Commit | Line | Data |
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47505b8b | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
60c778b2 | 2 | /* SCTP kernel implementation |
1da177e4 LT |
3 | * (C) Copyright IBM Corp. 2001, 2004 |
4 | * Copyright (c) 1999-2000 Cisco, Inc. | |
5 | * Copyright (c) 1999-2001 Motorola, Inc. | |
6 | * | |
60c778b2 | 7 | * This file is part of the SCTP kernel implementation |
1da177e4 LT |
8 | * |
9 | * These functions handle output processing. | |
10 | * | |
1da177e4 LT |
11 | * Please send any bug reports or fixes you make to the |
12 | * email address(es): | |
91705c61 | 13 | * lksctp developers <linux-sctp@vger.kernel.org> |
1da177e4 | 14 | * |
1da177e4 LT |
15 | * Written or modified by: |
16 | * La Monte H.P. Yarroll <piggy@acm.org> | |
17 | * Karl Knutson <karl@athena.chicago.il.us> | |
18 | * Jon Grimm <jgrimm@austin.ibm.com> | |
19 | * Sridhar Samudrala <sri@us.ibm.com> | |
1da177e4 LT |
20 | */ |
21 | ||
145ce502 JP |
22 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
23 | ||
1da177e4 LT |
24 | #include <linux/types.h> |
25 | #include <linux/kernel.h> | |
26 | #include <linux/wait.h> | |
27 | #include <linux/time.h> | |
28 | #include <linux/ip.h> | |
29 | #include <linux/ipv6.h> | |
30 | #include <linux/init.h> | |
5a0e3ad6 | 31 | #include <linux/slab.h> |
1da177e4 | 32 | #include <net/inet_ecn.h> |
8d2f9e81 | 33 | #include <net/ip.h> |
1da177e4 | 34 | #include <net/icmp.h> |
7c73a6fa | 35 | #include <net/net_namespace.h> |
1da177e4 | 36 | |
1da177e4 LT |
37 | #include <linux/socket.h> /* for sa_family_t */ |
38 | #include <net/sock.h> | |
39 | ||
40 | #include <net/sctp/sctp.h> | |
41 | #include <net/sctp/sm.h> | |
9ad0977f | 42 | #include <net/sctp/checksum.h> |
1da177e4 LT |
43 | |
44 | /* Forward declarations for private helpers. */ | |
86b36f2a XL |
45 | static enum sctp_xmit __sctp_packet_append_chunk(struct sctp_packet *packet, |
46 | struct sctp_chunk *chunk); | |
47 | static enum sctp_xmit sctp_packet_can_append_data(struct sctp_packet *packet, | |
48 | struct sctp_chunk *chunk); | |
e83963b7 | 49 | static void sctp_packet_append_data(struct sctp_packet *packet, |
86b36f2a XL |
50 | struct sctp_chunk *chunk); |
51 | static enum sctp_xmit sctp_packet_will_fit(struct sctp_packet *packet, | |
52 | struct sctp_chunk *chunk, | |
53 | u16 chunk_len); | |
1da177e4 | 54 | |
be297143 WY |
55 | static void sctp_packet_reset(struct sctp_packet *packet) |
56 | { | |
b7e10c25 RH |
57 | /* sctp_packet_transmit() relies on this to reset size to the |
58 | * current overhead after sending packets. | |
59 | */ | |
be297143 | 60 | packet->size = packet->overhead; |
b7e10c25 | 61 | |
be297143 WY |
62 | packet->has_cookie_echo = 0; |
63 | packet->has_sack = 0; | |
64 | packet->has_data = 0; | |
65 | packet->has_auth = 0; | |
66 | packet->ipfragok = 0; | |
67 | packet->auth = NULL; | |
68 | } | |
69 | ||
1da177e4 LT |
70 | /* Config a packet. |
71 | * This appears to be a followup set of initializations. | |
72 | */ | |
66b91d2c MRL |
73 | void sctp_packet_config(struct sctp_packet *packet, __u32 vtag, |
74 | int ecn_capable) | |
1da177e4 | 75 | { |
90017acc MRL |
76 | struct sctp_transport *tp = packet->transport; |
77 | struct sctp_association *asoc = tp->asoc; | |
feddd6c1 | 78 | struct sctp_sock *sp = NULL; |
df2729c3 | 79 | struct sock *sk; |
1da177e4 | 80 | |
bb33381d | 81 | pr_debug("%s: packet:%p vtag:0x%x\n", __func__, packet, vtag); |
1da177e4 | 82 | packet->vtag = vtag; |
1da177e4 | 83 | |
df2729c3 XL |
84 | /* do the following jobs only once for a flush schedule */ |
85 | if (!sctp_packet_empty(packet)) | |
86 | return; | |
90017acc | 87 | |
b7e10c25 | 88 | /* set packet max_size with pathmtu, then calculate overhead */ |
df2729c3 | 89 | packet->max_size = tp->pathmtu; |
feddd6c1 | 90 | |
b7e10c25 | 91 | if (asoc) { |
feddd6c1 MRL |
92 | sk = asoc->base.sk; |
93 | sp = sctp_sk(sk); | |
94 | } | |
95 | packet->overhead = sctp_mtu_payload(sp, 0, 0); | |
96 | packet->size = packet->overhead; | |
b7e10c25 | 97 | |
feddd6c1 | 98 | if (!asoc) |
df2729c3 | 99 | return; |
90017acc | 100 | |
df2729c3 | 101 | /* update dst or transport pathmtu if in need */ |
df2729c3 | 102 | if (!sctp_transport_dst_check(tp)) { |
feddd6c1 | 103 | sctp_transport_route(tp, NULL, sp); |
df2729c3 | 104 | if (asoc->param_flags & SPP_PMTUD_ENABLE) |
3ebfdf08 | 105 | sctp_assoc_sync_pmtu(asoc); |
7307e4fa | 106 | } else if (!sctp_transport_pl_enabled(tp) && |
02dc2ee7 XL |
107 | asoc->param_flags & SPP_PMTUD_ENABLE) { |
108 | if (!sctp_transport_pmtu_check(tp)) | |
69fec325 | 109 | sctp_assoc_sync_pmtu(asoc); |
90017acc MRL |
110 | } |
111 | ||
d805397c XL |
112 | if (asoc->pmtu_pending) { |
113 | if (asoc->param_flags & SPP_PMTUD_ENABLE) | |
114 | sctp_assoc_sync_pmtu(asoc); | |
115 | asoc->pmtu_pending = 0; | |
116 | } | |
117 | ||
df2729c3 XL |
118 | /* If there a is a prepend chunk stick it on the list before |
119 | * any other chunks get appended. | |
120 | */ | |
121 | if (ecn_capable) { | |
122 | struct sctp_chunk *chunk = sctp_get_ecne_prepend(asoc); | |
1da177e4 | 123 | |
1da177e4 LT |
124 | if (chunk) |
125 | sctp_packet_append_chunk(packet, chunk); | |
126 | } | |
df2729c3 XL |
127 | |
128 | if (!tp->dst) | |
129 | return; | |
130 | ||
131 | /* set packet max_size with gso_max_size if gso is enabled*/ | |
132 | rcu_read_lock(); | |
133 | if (__sk_dst_get(sk) != tp->dst) { | |
134 | dst_hold(tp->dst); | |
135 | sk_setup_caps(sk, tp->dst); | |
136 | } | |
137 | packet->max_size = sk_can_gso(sk) ? tp->dst->dev->gso_max_size | |
138 | : asoc->pathmtu; | |
139 | rcu_read_unlock(); | |
1da177e4 LT |
140 | } |
141 | ||
142 | /* Initialize the packet structure. */ | |
66b91d2c MRL |
143 | void sctp_packet_init(struct sctp_packet *packet, |
144 | struct sctp_transport *transport, | |
145 | __u16 sport, __u16 dport) | |
1da177e4 | 146 | { |
bb33381d | 147 | pr_debug("%s: packet:%p transport:%p\n", __func__, packet, transport); |
1da177e4 LT |
148 | |
149 | packet->transport = transport; | |
150 | packet->source_port = sport; | |
151 | packet->destination_port = dport; | |
79af02c2 | 152 | INIT_LIST_HEAD(&packet->chunk_list); |
b7e10c25 RH |
153 | /* The overhead will be calculated by sctp_packet_config() */ |
154 | packet->overhead = 0; | |
be297143 | 155 | sctp_packet_reset(packet); |
1da177e4 | 156 | packet->vtag = 0; |
1da177e4 LT |
157 | } |
158 | ||
159 | /* Free a packet. */ | |
160 | void sctp_packet_free(struct sctp_packet *packet) | |
161 | { | |
79af02c2 | 162 | struct sctp_chunk *chunk, *tmp; |
1da177e4 | 163 | |
bb33381d | 164 | pr_debug("%s: packet:%p\n", __func__, packet); |
1da177e4 | 165 | |
79af02c2 DM |
166 | list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) { |
167 | list_del_init(&chunk->list); | |
1da177e4 | 168 | sctp_chunk_free(chunk); |
79af02c2 | 169 | } |
1da177e4 LT |
170 | } |
171 | ||
172 | /* This routine tries to append the chunk to the offered packet. If adding | |
173 | * the chunk causes the packet to exceed the path MTU and COOKIE_ECHO chunk | |
174 | * is not present in the packet, it transmits the input packet. | |
175 | * Data can be bundled with a packet containing a COOKIE_ECHO chunk as long | |
176 | * as it can fit in the packet, but any more data that does not fit in this | |
177 | * packet can be sent only after receiving the COOKIE_ACK. | |
178 | */ | |
86b36f2a XL |
179 | enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet, |
180 | struct sctp_chunk *chunk, | |
181 | int one_packet, gfp_t gfp) | |
1da177e4 | 182 | { |
86b36f2a | 183 | enum sctp_xmit retval; |
1da177e4 | 184 | |
5b5e0928 | 185 | pr_debug("%s: packet:%p size:%zu chunk:%p size:%d\n", __func__, |
942b3235 | 186 | packet, packet->size, chunk, chunk->skb ? chunk->skb->len : -1); |
1da177e4 LT |
187 | |
188 | switch ((retval = (sctp_packet_append_chunk(packet, chunk)))) { | |
189 | case SCTP_XMIT_PMTU_FULL: | |
190 | if (!packet->has_cookie_echo) { | |
64519440 XL |
191 | int error = 0; |
192 | ||
cea8768f | 193 | error = sctp_packet_transmit(packet, gfp); |
1da177e4 LT |
194 | if (error < 0) |
195 | chunk->skb->sk->sk_err = -error; | |
196 | ||
197 | /* If we have an empty packet, then we can NOT ever | |
198 | * return PMTU_FULL. | |
199 | */ | |
2e3216cd VY |
200 | if (!one_packet) |
201 | retval = sctp_packet_append_chunk(packet, | |
202 | chunk); | |
1da177e4 LT |
203 | } |
204 | break; | |
205 | ||
206 | case SCTP_XMIT_RWND_FULL: | |
207 | case SCTP_XMIT_OK: | |
526cbef7 | 208 | case SCTP_XMIT_DELAY: |
1da177e4 | 209 | break; |
3ff50b79 | 210 | } |
1da177e4 LT |
211 | |
212 | return retval; | |
213 | } | |
214 | ||
fe59379b XL |
215 | /* Try to bundle a pad chunk into a packet with a heartbeat chunk for PLPMTUTD probe */ |
216 | static enum sctp_xmit sctp_packet_bundle_pad(struct sctp_packet *pkt, struct sctp_chunk *chunk) | |
217 | { | |
218 | struct sctp_transport *t = pkt->transport; | |
219 | struct sctp_chunk *pad; | |
220 | int overhead = 0; | |
221 | ||
222 | if (!chunk->pmtu_probe) | |
223 | return SCTP_XMIT_OK; | |
224 | ||
225 | /* calculate the Padding Data size for the pad chunk */ | |
226 | overhead += sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr); | |
227 | overhead += sizeof(struct sctp_sender_hb_info) + sizeof(struct sctp_pad_chunk); | |
228 | pad = sctp_make_pad(t->asoc, t->pl.probe_size - overhead); | |
229 | if (!pad) | |
230 | return SCTP_XMIT_DELAY; | |
231 | ||
232 | list_add_tail(&pad->list, &pkt->chunk_list); | |
233 | pkt->size += SCTP_PAD4(ntohs(pad->chunk_hdr->length)); | |
234 | chunk->transport = t; | |
235 | ||
236 | return SCTP_XMIT_OK; | |
237 | } | |
238 | ||
4cd57c80 | 239 | /* Try to bundle an auth chunk into the packet. */ |
86b36f2a XL |
240 | static enum sctp_xmit sctp_packet_bundle_auth(struct sctp_packet *pkt, |
241 | struct sctp_chunk *chunk) | |
4cd57c80 VY |
242 | { |
243 | struct sctp_association *asoc = pkt->transport->asoc; | |
86b36f2a | 244 | enum sctp_xmit retval = SCTP_XMIT_OK; |
4cd57c80 | 245 | struct sctp_chunk *auth; |
4cd57c80 VY |
246 | |
247 | /* if we don't have an association, we can't do authentication */ | |
248 | if (!asoc) | |
249 | return retval; | |
250 | ||
251 | /* See if this is an auth chunk we are bundling or if | |
252 | * auth is already bundled. | |
253 | */ | |
4007cc88 | 254 | if (chunk->chunk_hdr->type == SCTP_CID_AUTH || pkt->has_auth) |
4cd57c80 VY |
255 | return retval; |
256 | ||
257 | /* if the peer did not request this chunk to be authenticated, | |
258 | * don't do it | |
259 | */ | |
260 | if (!chunk->auth) | |
261 | return retval; | |
262 | ||
1b1e0bc9 | 263 | auth = sctp_make_auth(asoc, chunk->shkey->key_id); |
4cd57c80 VY |
264 | if (!auth) |
265 | return retval; | |
266 | ||
1b1e0bc9 XL |
267 | auth->shkey = chunk->shkey; |
268 | sctp_auth_shkey_hold(auth->shkey); | |
269 | ||
ed106277 NH |
270 | retval = __sctp_packet_append_chunk(pkt, auth); |
271 | ||
272 | if (retval != SCTP_XMIT_OK) | |
273 | sctp_chunk_free(auth); | |
4cd57c80 VY |
274 | |
275 | return retval; | |
276 | } | |
277 | ||
1da177e4 | 278 | /* Try to bundle a SACK with the packet. */ |
86b36f2a XL |
279 | static enum sctp_xmit sctp_packet_bundle_sack(struct sctp_packet *pkt, |
280 | struct sctp_chunk *chunk) | |
1da177e4 | 281 | { |
86b36f2a | 282 | enum sctp_xmit retval = SCTP_XMIT_OK; |
1da177e4 LT |
283 | |
284 | /* If sending DATA and haven't aleady bundled a SACK, try to | |
285 | * bundle one in to the packet. | |
286 | */ | |
287 | if (sctp_chunk_is_data(chunk) && !pkt->has_sack && | |
288 | !pkt->has_cookie_echo) { | |
289 | struct sctp_association *asoc; | |
af87b823 | 290 | struct timer_list *timer; |
1da177e4 | 291 | asoc = pkt->transport->asoc; |
af87b823 | 292 | timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK]; |
1da177e4 | 293 | |
af87b823 DG |
294 | /* If the SACK timer is running, we have a pending SACK */ |
295 | if (timer_pending(timer)) { | |
1da177e4 | 296 | struct sctp_chunk *sack; |
4244854d NH |
297 | |
298 | if (pkt->transport->sack_generation != | |
299 | pkt->transport->asoc->peer.sack_generation) | |
300 | return retval; | |
301 | ||
1da177e4 LT |
302 | asoc->a_rwnd = asoc->rwnd; |
303 | sack = sctp_make_sack(asoc); | |
304 | if (sack) { | |
ed106277 NH |
305 | retval = __sctp_packet_append_chunk(pkt, sack); |
306 | if (retval != SCTP_XMIT_OK) { | |
307 | sctp_chunk_free(sack); | |
308 | goto out; | |
309 | } | |
4e7696d9 | 310 | SCTP_INC_STATS(asoc->base.net, |
7af03301 XL |
311 | SCTP_MIB_OUTCTRLCHUNKS); |
312 | asoc->stats.octrlchunks++; | |
1da177e4 | 313 | asoc->peer.sack_needed = 0; |
af87b823 | 314 | if (del_timer(timer)) |
1da177e4 LT |
315 | sctp_association_put(asoc); |
316 | } | |
317 | } | |
318 | } | |
ed106277 | 319 | out: |
1da177e4 LT |
320 | return retval; |
321 | } | |
322 | ||
ed106277 | 323 | |
1da177e4 LT |
324 | /* Append a chunk to the offered packet reporting back any inability to do |
325 | * so. | |
326 | */ | |
86b36f2a XL |
327 | static enum sctp_xmit __sctp_packet_append_chunk(struct sctp_packet *packet, |
328 | struct sctp_chunk *chunk) | |
1da177e4 | 329 | { |
e2f036a9 | 330 | __u16 chunk_len = SCTP_PAD4(ntohs(chunk->chunk_hdr->length)); |
86b36f2a | 331 | enum sctp_xmit retval = SCTP_XMIT_OK; |
1da177e4 | 332 | |
e83963b7 VY |
333 | /* Check to see if this chunk will fit into the packet */ |
334 | retval = sctp_packet_will_fit(packet, chunk, chunk_len); | |
335 | if (retval != SCTP_XMIT_OK) | |
336 | goto finish; | |
1da177e4 | 337 | |
e83963b7 | 338 | /* We believe that this chunk is OK to add to the packet */ |
4cd57c80 | 339 | switch (chunk->chunk_hdr->type) { |
f7010e61 | 340 | case SCTP_CID_DATA: |
668c9beb | 341 | case SCTP_CID_I_DATA: |
e83963b7 VY |
342 | /* Account for the data being in the packet */ |
343 | sctp_packet_append_data(packet, chunk); | |
1da177e4 LT |
344 | /* Disallow SACK bundling after DATA. */ |
345 | packet->has_sack = 1; | |
4cd57c80 VY |
346 | /* Disallow AUTH bundling after DATA */ |
347 | packet->has_auth = 1; | |
348 | /* Let it be knows that packet has DATA in it */ | |
349 | packet->has_data = 1; | |
759af00e VY |
350 | /* timestamp the chunk for rtx purposes */ |
351 | chunk->sent_at = jiffies; | |
a6c2f792 XL |
352 | /* Mainly used for prsctp RTX policy */ |
353 | chunk->sent_count++; | |
4cd57c80 | 354 | break; |
f7010e61 | 355 | case SCTP_CID_COOKIE_ECHO: |
1da177e4 | 356 | packet->has_cookie_echo = 1; |
4cd57c80 VY |
357 | break; |
358 | ||
f7010e61 | 359 | case SCTP_CID_SACK: |
1da177e4 | 360 | packet->has_sack = 1; |
196d6759 MB |
361 | if (chunk->asoc) |
362 | chunk->asoc->stats.osacks++; | |
4cd57c80 VY |
363 | break; |
364 | ||
f7010e61 | 365 | case SCTP_CID_AUTH: |
4cd57c80 VY |
366 | packet->has_auth = 1; |
367 | packet->auth = chunk; | |
368 | break; | |
369 | } | |
1da177e4 LT |
370 | |
371 | /* It is OK to send this chunk. */ | |
79af02c2 | 372 | list_add_tail(&chunk->list, &packet->chunk_list); |
1da177e4 LT |
373 | packet->size += chunk_len; |
374 | chunk->transport = packet->transport; | |
375 | finish: | |
376 | return retval; | |
377 | } | |
378 | ||
ed106277 NH |
379 | /* Append a chunk to the offered packet reporting back any inability to do |
380 | * so. | |
381 | */ | |
86b36f2a XL |
382 | enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet, |
383 | struct sctp_chunk *chunk) | |
ed106277 | 384 | { |
86b36f2a | 385 | enum sctp_xmit retval = SCTP_XMIT_OK; |
ed106277 | 386 | |
bb33381d | 387 | pr_debug("%s: packet:%p chunk:%p\n", __func__, packet, chunk); |
ed106277 NH |
388 | |
389 | /* Data chunks are special. Before seeing what else we can | |
390 | * bundle into this packet, check to see if we are allowed to | |
391 | * send this DATA. | |
392 | */ | |
393 | if (sctp_chunk_is_data(chunk)) { | |
394 | retval = sctp_packet_can_append_data(packet, chunk); | |
395 | if (retval != SCTP_XMIT_OK) | |
396 | goto finish; | |
397 | } | |
398 | ||
399 | /* Try to bundle AUTH chunk */ | |
400 | retval = sctp_packet_bundle_auth(packet, chunk); | |
401 | if (retval != SCTP_XMIT_OK) | |
402 | goto finish; | |
403 | ||
404 | /* Try to bundle SACK chunk */ | |
405 | retval = sctp_packet_bundle_sack(packet, chunk); | |
406 | if (retval != SCTP_XMIT_OK) | |
407 | goto finish; | |
408 | ||
409 | retval = __sctp_packet_append_chunk(packet, chunk); | |
fe59379b XL |
410 | if (retval != SCTP_XMIT_OK) |
411 | goto finish; | |
412 | ||
413 | retval = sctp_packet_bundle_pad(packet, chunk); | |
ed106277 NH |
414 | |
415 | finish: | |
416 | return retval; | |
417 | } | |
418 | ||
99519122 XL |
419 | static void sctp_packet_gso_append(struct sk_buff *head, struct sk_buff *skb) |
420 | { | |
421 | if (SCTP_OUTPUT_CB(head)->last == head) | |
422 | skb_shinfo(head)->frag_list = skb; | |
423 | else | |
424 | SCTP_OUTPUT_CB(head)->last->next = skb; | |
425 | SCTP_OUTPUT_CB(head)->last = skb; | |
426 | ||
427 | head->truesize += skb->truesize; | |
428 | head->data_len += skb->len; | |
429 | head->len += skb->len; | |
0d32f177 | 430 | refcount_add(skb->truesize, &head->sk->sk_wmem_alloc); |
99519122 XL |
431 | |
432 | __skb_header_release(skb); | |
433 | } | |
434 | ||
e4ff952a XL |
435 | static int sctp_packet_pack(struct sctp_packet *packet, |
436 | struct sk_buff *head, int gso, gfp_t gfp) | |
1da177e4 LT |
437 | { |
438 | struct sctp_transport *tp = packet->transport; | |
e4ff952a | 439 | struct sctp_auth_chunk *auth = NULL; |
79af02c2 | 440 | struct sctp_chunk *chunk, *tmp; |
e4ff952a XL |
441 | int pkt_count = 0, pkt_size; |
442 | struct sock *sk = head->sk; | |
443 | struct sk_buff *nskb; | |
ecc515d7 | 444 | int auth_len = 0; |
1da177e4 | 445 | |
90017acc | 446 | if (gso) { |
90017acc | 447 | skb_shinfo(head)->gso_type = sk->sk_gso_type; |
99519122 | 448 | SCTP_OUTPUT_CB(head)->last = head; |
e4ff952a XL |
449 | } else { |
450 | nskb = head; | |
451 | pkt_size = packet->size; | |
452 | goto merge; | |
90017acc | 453 | } |
1da177e4 | 454 | |
90017acc | 455 | do { |
e4ff952a XL |
456 | /* calculate the pkt_size and alloc nskb */ |
457 | pkt_size = packet->overhead; | |
458 | list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, | |
459 | list) { | |
460 | int padded = SCTP_PAD4(chunk->skb->len); | |
6eabca54 | 461 | |
e4ff952a XL |
462 | if (chunk == packet->auth) |
463 | auth_len = padded; | |
464 | else if (auth_len + padded + packet->overhead > | |
465 | tp->pathmtu) | |
466 | return 0; | |
467 | else if (pkt_size + padded > tp->pathmtu) | |
468 | break; | |
469 | pkt_size += padded; | |
90017acc | 470 | } |
e4ff952a XL |
471 | nskb = alloc_skb(pkt_size + MAX_HEADER, gfp); |
472 | if (!nskb) | |
473 | return 0; | |
474 | skb_reserve(nskb, packet->overhead + MAX_HEADER); | |
1da177e4 | 475 | |
e4ff952a XL |
476 | merge: |
477 | /* merge chunks into nskb and append nskb into head list */ | |
90017acc MRL |
478 | pkt_size -= packet->overhead; |
479 | list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) { | |
e4ff952a XL |
480 | int padding; |
481 | ||
90017acc MRL |
482 | list_del_init(&chunk->list); |
483 | if (sctp_chunk_is_data(chunk)) { | |
cc6ac9bc XL |
484 | if (!sctp_chunk_retransmitted(chunk) && |
485 | !tp->rto_pending) { | |
90017acc MRL |
486 | chunk->rtt_in_progress = 1; |
487 | tp->rto_pending = 1; | |
488 | } | |
90017acc MRL |
489 | } |
490 | ||
e2f036a9 | 491 | padding = SCTP_PAD4(chunk->skb->len) - chunk->skb->len; |
90017acc | 492 | if (padding) |
b080db58 | 493 | skb_put_zero(chunk->skb, padding); |
90017acc | 494 | |
90017acc | 495 | if (chunk == packet->auth) |
e4ff952a XL |
496 | auth = (struct sctp_auth_chunk *) |
497 | skb_tail_pointer(nskb); | |
90017acc | 498 | |
59ae1d12 | 499 | skb_put_data(nskb, chunk->skb->data, chunk->skb->len); |
1da177e4 | 500 | |
90017acc MRL |
501 | pr_debug("*** Chunk:%p[%s] %s 0x%x, length:%d, chunk->skb->len:%d, rtt_in_progress:%d\n", |
502 | chunk, | |
503 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)), | |
504 | chunk->has_tsn ? "TSN" : "No TSN", | |
505 | chunk->has_tsn ? ntohl(chunk->subh.data_hdr->tsn) : 0, | |
506 | ntohs(chunk->chunk_hdr->length), chunk->skb->len, | |
507 | chunk->rtt_in_progress); | |
508 | ||
e2f036a9 | 509 | pkt_size -= SCTP_PAD4(chunk->skb->len); |
1da177e4 | 510 | |
f1533cce | 511 | if (!sctp_chunk_is_data(chunk) && chunk != packet->auth) |
90017acc MRL |
512 | sctp_chunk_free(chunk); |
513 | ||
514 | if (!pkt_size) | |
515 | break; | |
516 | } | |
517 | ||
e4ff952a | 518 | if (auth) { |
1b1e0bc9 XL |
519 | sctp_auth_calculate_hmac(tp->asoc, nskb, auth, |
520 | packet->auth->shkey, gfp); | |
e4ff952a XL |
521 | /* free auth if no more chunks, or add it back */ |
522 | if (list_empty(&packet->chunk_list)) | |
523 | sctp_chunk_free(packet->auth); | |
524 | else | |
1aa25ec2 XL |
525 | list_add(&packet->auth->list, |
526 | &packet->chunk_list); | |
f1533cce MRL |
527 | } |
528 | ||
99519122 XL |
529 | if (gso) |
530 | sctp_packet_gso_append(head, nskb); | |
e4ff952a XL |
531 | |
532 | pkt_count++; | |
90017acc | 533 | } while (!list_empty(&packet->chunk_list)); |
4cd57c80 | 534 | |
e4ff952a XL |
535 | if (gso) { |
536 | memset(head->cb, 0, max(sizeof(struct inet_skb_parm), | |
537 | sizeof(struct inet6_skb_parm))); | |
538 | skb_shinfo(head)->gso_segs = pkt_count; | |
539 | skb_shinfo(head)->gso_size = GSO_BY_FRAGS; | |
e4ff952a | 540 | goto chksum; |
8dc92f7e | 541 | } |
1da177e4 | 542 | |
e4ff952a XL |
543 | if (sctp_checksum_disable) |
544 | return 1; | |
1da177e4 | 545 | |
600af7fd XL |
546 | if (!(tp->dst->dev->features & NETIF_F_SCTP_CRC) || |
547 | dst_xfrm(tp->dst) || packet->ipfragok || tp->encap_port) { | |
e4ff952a XL |
548 | struct sctphdr *sh = |
549 | (struct sctphdr *)skb_transport_header(head); | |
1da177e4 | 550 | |
e4ff952a XL |
551 | sh->checksum = sctp_compute_cksum(head, 0); |
552 | } else { | |
553 | chksum: | |
554 | head->ip_summed = CHECKSUM_PARTIAL; | |
dba00306 | 555 | head->csum_not_inet = 1; |
e4ff952a XL |
556 | head->csum_start = skb_transport_header(head) - head->head; |
557 | head->csum_offset = offsetof(struct sctphdr, checksum); | |
1da177e4 LT |
558 | } |
559 | ||
e4ff952a XL |
560 | return pkt_count; |
561 | } | |
562 | ||
563 | /* All packets are sent to the network through this function from | |
564 | * sctp_outq_tail(). | |
565 | * | |
566 | * The return value is always 0 for now. | |
567 | */ | |
568 | int sctp_packet_transmit(struct sctp_packet *packet, gfp_t gfp) | |
569 | { | |
570 | struct sctp_transport *tp = packet->transport; | |
571 | struct sctp_association *asoc = tp->asoc; | |
572 | struct sctp_chunk *chunk, *tmp; | |
573 | int pkt_count, gso = 0; | |
e4ff952a XL |
574 | struct sk_buff *head; |
575 | struct sctphdr *sh; | |
576 | struct sock *sk; | |
1da177e4 | 577 | |
e4ff952a XL |
578 | pr_debug("%s: packet:%p\n", __func__, packet); |
579 | if (list_empty(&packet->chunk_list)) | |
580 | return 0; | |
581 | chunk = list_entry(packet->chunk_list.next, struct sctp_chunk, list); | |
582 | sk = chunk->skb->sk; | |
1da177e4 | 583 | |
e4ff952a | 584 | /* check gso */ |
fe59379b | 585 | if (packet->size > tp->pathmtu && !packet->ipfragok && !chunk->pmtu_probe) { |
e4ff952a XL |
586 | if (!sk_can_gso(sk)) { |
587 | pr_err_once("Trying to GSO but underlying device doesn't support it."); | |
588 | goto out; | |
1da177e4 | 589 | } |
e4ff952a XL |
590 | gso = 1; |
591 | } | |
592 | ||
593 | /* alloc head skb */ | |
594 | head = alloc_skb((gso ? packet->overhead : packet->size) + | |
595 | MAX_HEADER, gfp); | |
596 | if (!head) | |
597 | goto out; | |
598 | skb_reserve(head, packet->overhead + MAX_HEADER); | |
02968ccf | 599 | skb_set_owner_w(head, sk); |
e4ff952a XL |
600 | |
601 | /* set sctp header */ | |
d58ff351 | 602 | sh = skb_push(head, sizeof(struct sctphdr)); |
e4ff952a XL |
603 | skb_reset_transport_header(head); |
604 | sh->source = htons(packet->source_port); | |
605 | sh->dest = htons(packet->destination_port); | |
606 | sh->vtag = htonl(packet->vtag); | |
607 | sh->checksum = 0; | |
608 | ||
df2729c3 | 609 | /* drop packet if no dst */ |
600af7fd | 610 | if (!tp->dst) { |
e4ff952a XL |
611 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); |
612 | kfree_skb(head); | |
613 | goto out; | |
614 | } | |
1da177e4 | 615 | |
e4ff952a XL |
616 | /* pack up chunks */ |
617 | pkt_count = sctp_packet_pack(packet, head, gso, gfp); | |
618 | if (!pkt_count) { | |
619 | kfree_skb(head); | |
620 | goto out; | |
621 | } | |
90017acc MRL |
622 | pr_debug("***sctp_transmit_packet*** skb->len:%d\n", head->len); |
623 | ||
e4ff952a XL |
624 | /* start autoclose timer */ |
625 | if (packet->has_data && sctp_state(asoc, ESTABLISHED) && | |
626 | asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) { | |
627 | struct timer_list *timer = | |
628 | &asoc->timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE]; | |
629 | unsigned long timeout = | |
630 | asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]; | |
1da177e4 | 631 | |
e4ff952a XL |
632 | if (!mod_timer(timer, jiffies + timeout)) |
633 | sctp_association_hold(asoc); | |
634 | } | |
90017acc | 635 | |
e4ff952a XL |
636 | /* sctp xmit */ |
637 | tp->af_specific->ecn_capable(sk); | |
638 | if (asoc) { | |
639 | asoc->stats.opackets += pkt_count; | |
640 | if (asoc->peer.last_sent_to != tp) | |
641 | asoc->peer.last_sent_to = tp; | |
90017acc MRL |
642 | } |
643 | head->ignore_df = packet->ipfragok; | |
486a43db | 644 | if (tp->dst_pending_confirm) |
c86a773c JA |
645 | skb_set_dst_pending_confirm(head, 1); |
646 | /* neighbour should be confirmed on successful transmission or | |
647 | * positive error | |
648 | */ | |
486a43db XL |
649 | if (tp->af_specific->sctp_xmit(head, tp) >= 0 && |
650 | tp->dst_pending_confirm) | |
c86a773c | 651 | tp->dst_pending_confirm = 0; |
1da177e4 | 652 | |
e4ff952a | 653 | out: |
79af02c2 DM |
654 | list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) { |
655 | list_del_init(&chunk->list); | |
1da177e4 | 656 | if (!sctp_chunk_is_data(chunk)) |
d808ad9a | 657 | sctp_chunk_free(chunk); |
1da177e4 | 658 | } |
41001faf | 659 | sctp_packet_reset(packet); |
e4ff952a | 660 | return 0; |
1da177e4 LT |
661 | } |
662 | ||
663 | /******************************************************************** | |
664 | * 2nd Level Abstractions | |
665 | ********************************************************************/ | |
666 | ||
e83963b7 | 667 | /* This private function check to see if a chunk can be added */ |
86b36f2a XL |
668 | static enum sctp_xmit sctp_packet_can_append_data(struct sctp_packet *packet, |
669 | struct sctp_chunk *chunk) | |
1da177e4 | 670 | { |
e83963b7 | 671 | size_t datasize, rwnd, inflight, flight_size; |
1da177e4 | 672 | struct sctp_transport *transport = packet->transport; |
1da177e4 | 673 | struct sctp_association *asoc = transport->asoc; |
1da177e4 LT |
674 | struct sctp_outq *q = &asoc->outqueue; |
675 | ||
676 | /* RFC 2960 6.1 Transmission of DATA Chunks | |
677 | * | |
678 | * A) At any given time, the data sender MUST NOT transmit new data to | |
679 | * any destination transport address if its peer's rwnd indicates | |
680 | * that the peer has no buffer space (i.e. rwnd is 0, see Section | |
681 | * 6.2.1). However, regardless of the value of rwnd (including if it | |
682 | * is 0), the data sender can always have one DATA chunk in flight to | |
683 | * the receiver if allowed by cwnd (see rule B below). This rule | |
684 | * allows the sender to probe for a change in rwnd that the sender | |
685 | * missed due to the SACK having been lost in transit from the data | |
686 | * receiver to the data sender. | |
687 | */ | |
688 | ||
689 | rwnd = asoc->peer.rwnd; | |
e83963b7 VY |
690 | inflight = q->outstanding_bytes; |
691 | flight_size = transport->flight_size; | |
1da177e4 LT |
692 | |
693 | datasize = sctp_data_size(chunk); | |
694 | ||
723189fa DL |
695 | if (datasize > rwnd && inflight > 0) |
696 | /* We have (at least) one data chunk in flight, | |
697 | * so we can't fall back to rule 6.1 B). | |
698 | */ | |
699 | return SCTP_XMIT_RWND_FULL; | |
1da177e4 | 700 | |
1da177e4 LT |
701 | /* RFC 2960 6.1 Transmission of DATA Chunks |
702 | * | |
703 | * B) At any given time, the sender MUST NOT transmit new data | |
704 | * to a given transport address if it has cwnd or more bytes | |
705 | * of data outstanding to that transport address. | |
706 | */ | |
707 | /* RFC 7.2.4 & the Implementers Guide 2.8. | |
708 | * | |
709 | * 3) ... | |
710 | * When a Fast Retransmit is being performed the sender SHOULD | |
711 | * ignore the value of cwnd and SHOULD NOT delay retransmission. | |
712 | */ | |
723189fa DL |
713 | if (chunk->fast_retransmit != SCTP_NEED_FRTX && |
714 | flight_size >= transport->cwnd) | |
715 | return SCTP_XMIT_RWND_FULL; | |
1da177e4 LT |
716 | |
717 | /* Nagle's algorithm to solve small-packet problem: | |
718 | * Inhibit the sending of new chunks when new outgoing data arrives | |
719 | * if any previously transmitted data on the connection remains | |
720 | * unacknowledged. | |
721 | */ | |
1da177e4 | 722 | |
4ea0c32f | 723 | if ((sctp_sk(asoc->base.sk)->nodelay || inflight == 0) && |
f9ba3501 | 724 | !asoc->force_delay) |
4ea0c32f | 725 | /* Nothing unacked */ |
723189fa DL |
726 | return SCTP_XMIT_OK; |
727 | ||
728 | if (!sctp_packet_empty(packet)) | |
729 | /* Append to packet */ | |
730 | return SCTP_XMIT_OK; | |
731 | ||
723189fa DL |
732 | if (!sctp_state(asoc, ESTABLISHED)) |
733 | return SCTP_XMIT_OK; | |
734 | ||
735 | /* Check whether this chunk and all the rest of pending data will fit | |
736 | * or delay in hopes of bundling a full sized packet. | |
737 | */ | |
9f8d3147 | 738 | if (chunk->skb->len + q->out_qlen > transport->pathmtu - |
668c9beb | 739 | packet->overhead - sctp_datachk_len(&chunk->asoc->stream) - 4) |
723189fa DL |
740 | /* Enough data queued to fill a packet */ |
741 | return SCTP_XMIT_OK; | |
742 | ||
743 | /* Don't delay large message writes that may have been fragmented */ | |
744 | if (!chunk->msg->can_delay) | |
745 | return SCTP_XMIT_OK; | |
746 | ||
747 | /* Defer until all data acked or packet full */ | |
526cbef7 | 748 | return SCTP_XMIT_DELAY; |
e83963b7 VY |
749 | } |
750 | ||
751 | /* This private function does management things when adding DATA chunk */ | |
752 | static void sctp_packet_append_data(struct sctp_packet *packet, | |
753 | struct sctp_chunk *chunk) | |
754 | { | |
755 | struct sctp_transport *transport = packet->transport; | |
756 | size_t datasize = sctp_data_size(chunk); | |
757 | struct sctp_association *asoc = transport->asoc; | |
758 | u32 rwnd = asoc->peer.rwnd; | |
759 | ||
1da177e4 LT |
760 | /* Keep track of how many bytes are in flight over this transport. */ |
761 | transport->flight_size += datasize; | |
762 | ||
763 | /* Keep track of how many bytes are in flight to the receiver. */ | |
764 | asoc->outqueue.outstanding_bytes += datasize; | |
765 | ||
a76c0adf | 766 | /* Update our view of the receiver's rwnd. */ |
1da177e4 LT |
767 | if (datasize < rwnd) |
768 | rwnd -= datasize; | |
769 | else | |
770 | rwnd = 0; | |
771 | ||
772 | asoc->peer.rwnd = rwnd; | |
d8dd1578 | 773 | sctp_chunk_assign_tsn(chunk); |
668c9beb | 774 | asoc->stream.si->assign_number(chunk); |
e83963b7 VY |
775 | } |
776 | ||
86b36f2a XL |
777 | static enum sctp_xmit sctp_packet_will_fit(struct sctp_packet *packet, |
778 | struct sctp_chunk *chunk, | |
779 | u16 chunk_len) | |
e83963b7 | 780 | { |
86b36f2a | 781 | enum sctp_xmit retval = SCTP_XMIT_OK; |
7303a147 | 782 | size_t psize, pmtu, maxsize; |
e83963b7 | 783 | |
1b1e0bc9 XL |
784 | /* Don't bundle in this packet if this chunk's auth key doesn't |
785 | * match other chunks already enqueued on this packet. Also, | |
786 | * don't bundle the chunk with auth key if other chunks in this | |
787 | * packet don't have auth key. | |
788 | */ | |
789 | if ((packet->auth && chunk->shkey != packet->auth->shkey) || | |
790 | (!packet->auth && chunk->shkey && | |
791 | chunk->chunk_hdr->type != SCTP_CID_AUTH)) | |
792 | return SCTP_XMIT_PMTU_FULL; | |
793 | ||
e83963b7 | 794 | psize = packet->size; |
90017acc MRL |
795 | if (packet->transport->asoc) |
796 | pmtu = packet->transport->asoc->pathmtu; | |
797 | else | |
798 | pmtu = packet->transport->pathmtu; | |
e83963b7 VY |
799 | |
800 | /* Decide if we need to fragment or resubmit later. */ | |
90017acc MRL |
801 | if (psize + chunk_len > pmtu) { |
802 | /* It's OK to fragment at IP level if any one of the following | |
e83963b7 | 803 | * is true: |
90017acc MRL |
804 | * 1. The packet is empty (meaning this chunk is greater |
805 | * the MTU) | |
806 | * 2. The packet doesn't have any data in it yet and data | |
807 | * requires authentication. | |
e83963b7 | 808 | */ |
90017acc | 809 | if (sctp_packet_empty(packet) || |
e83963b7 VY |
810 | (!packet->has_data && chunk->auth)) { |
811 | /* We no longer do re-fragmentation. | |
812 | * Just fragment at the IP layer, if we | |
813 | * actually hit this condition | |
814 | */ | |
815 | packet->ipfragok = 1; | |
90017acc | 816 | goto out; |
e83963b7 | 817 | } |
90017acc | 818 | |
7303a147 MRL |
819 | /* Similarly, if this chunk was built before a PMTU |
820 | * reduction, we have to fragment it at IP level now. So | |
821 | * if the packet already contains something, we need to | |
822 | * flush. | |
823 | */ | |
824 | maxsize = pmtu - packet->overhead; | |
825 | if (packet->auth) | |
e2f036a9 | 826 | maxsize -= SCTP_PAD4(packet->auth->skb->len); |
7303a147 MRL |
827 | if (chunk_len > maxsize) |
828 | retval = SCTP_XMIT_PMTU_FULL; | |
829 | ||
90017acc MRL |
830 | /* It is also okay to fragment if the chunk we are |
831 | * adding is a control chunk, but only if current packet | |
832 | * is not a GSO one otherwise it causes fragmentation of | |
833 | * a large frame. So in this case we allow the | |
834 | * fragmentation by forcing it to be in a new packet. | |
835 | */ | |
836 | if (!sctp_chunk_is_data(chunk) && packet->has_data) | |
837 | retval = SCTP_XMIT_PMTU_FULL; | |
838 | ||
839 | if (psize + chunk_len > packet->max_size) | |
840 | /* Hit GSO/PMTU limit, gotta flush */ | |
841 | retval = SCTP_XMIT_PMTU_FULL; | |
842 | ||
843 | if (!packet->transport->burst_limited && | |
844 | psize + chunk_len > (packet->transport->cwnd >> 1)) | |
845 | /* Do not allow a single GSO packet to use more | |
846 | * than half of cwnd. | |
847 | */ | |
848 | retval = SCTP_XMIT_PMTU_FULL; | |
849 | ||
850 | if (packet->transport->burst_limited && | |
851 | psize + chunk_len > (packet->transport->burst_limited >> 1)) | |
852 | /* Do not allow a single GSO packet to use more | |
853 | * than half of original cwnd. | |
854 | */ | |
855 | retval = SCTP_XMIT_PMTU_FULL; | |
856 | /* Otherwise it will fit in the GSO packet */ | |
e83963b7 | 857 | } |
1da177e4 | 858 | |
90017acc | 859 | out: |
1da177e4 LT |
860 | return retval; |
861 | } |